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The Fitness-Fatigue Model Revisited: Implications for Planning Short- and Long-Term Training
Abstract
High-level human performance requires years of diligent training. Coaches and athletes should not leave performance adaptations to chance. Proper planning and organization of training results in the desired performance outcomes, and empirical and scientific evidence is in support of modeling training after the fitness-fatigue theory. From the design of the yearly training structure to each individual training session, an athlete's training plan should account for fitness and fatigue after-effects in an effort to maximize the effects of training.
... Noteworthy, the magnitude of PAPE depends on the balance between fatigue and potentiation, which is related to some factors including individual physical fitness (Chiu and Barnes, 2003;Guerra Junior et al., 2020), athlete's training status (Wilson et al., 2013), the endurance running performance level (Del Rosso et al., 2021), the rest period after CA (Wilson et al., 2013), and intensity of CAs (Seitz and Haff, 2016;Wilson et al., 2013). An enhancement in performance occurs when potentiation overlaps fatigue, however, performance decreases when fatigue overlaps the potentiation (Rassier and Macintosh, 2000). ...
... These results suggest that non-runners may also benefit from PAPE after a non-fatiguing CA. Previously, Chiu and Barnes (2003) observed an impairment (1 to 4%) in jump performance (i.e., drop jump) for physically active individuals after a CA performed at 90% of the 1RM (five sets / 1 repetition), whereas for trained individuals, jump performance improved (1 to 3%). Although with resistance training, this and previous studies may confirm that CA intensity adjusted to the individual's conditioning level may be an important factor for PAPE in physically active individuals. ...
... These results reinforce that athletes with more volume of endurance training could benefit more from PAPE after intense CAs. Previous studies have already shown that training status can influence the magnitude of PAPE (Chiu and Barnes, 2003;Wilson et al., 2013) in resistance trained individuals. Thus, this is the first study confirming that more trained runners present greater PAPE. ...
The aim of this study was to verify post-activation performance enhancement (PAPE) in jumping and sprinting after two endurance volume-equated running protocols with different intensities, in runners vs. active individuals. Nine recreational runners (age: 34.5 ± 9.3 years, body mass: 73.1 ± 11.9 kg, body height: 1.76 ± 0.06 m, 17.4 ± 4.4 %body fat; maximum aerobic speed [MAS]: 16.4 ± 1.0 km•h⁻¹), and 9 active individuals (age: 34.1 ± 9.4 years; body mass: 83.2 ± 7.7 kg; body height: 1.79 ± 0.06 m; 25.6 ± 5.4 %body fat; MAS: 13.3 ± 1.2 km•h⁻¹) volunteered for participation. The evaluations were performed over three days as follows: 1) anthropometric measures, physical fitness tests, and the University of Montreal Track Test (UMTT) to determine MAS and the distance to be covered in the running protocols; 2 and 3) the countermovement jump (CMJ) and the flying 20-m sprint (SPRINT) were assessed pre- and post-running at 70% of MAS or a time trial race (TTR), equated by volume and completed in random order. A three-way ANOVA (time*group*running) was performed to analyze the PAPE effects. The results showed a time effect (F = 10 .716; p < 0.01) and a group*running interaction (F = 12.094; p < 0.01) for the CMJ, indicating that active individuals demonstrated PAPE after running at 70% of MAS, while for runners both running interventions (70% of MAS and TTR) induced PAPE in CMJ performances. For the SPRINT, a time*group interaction (F = 4.790; p = 0.044) and a group effect were observed, with runners showing greater SPRINT performances than active individuals. From the current results, it can be suggested that training background and intensity can modulate PAPE responses in jumping and sprinting after volume-equated running protocols at different intensities.
... However, the postpriming response following comparable volume loads of resistance exercise seems to be strongly influenced by the duration separating the exercise stimulus and neuromuscular performance test. Furthermore, the literature suggests that training status will influence the manifestation of potentiation or fatigue following resistance exercise involving similar volume loads (21,22,114). Studies that have reported significant postpriming performance improvements in resistancetrained participants within 8 hours used volume loads between 560-1,190 AU (38,57,69,101). ...
... A higher percentage of these fibers strongly correlates with greater relative MHC IIa area, an indicator of the strength training history (51,52,54,142). As such, the magnitude of potentiation or fatigue following resistance priming exercise completed on the same day may be influenced by training status (21,22). Nevertheless, further research examining the relationship between these muscle adaptations and the postexercise response subsequent to resistance priming strategies with lower exercise volumes that may be effective to improve performance within this time frame is needed. ...
... Given that high-intensity resistance exercise has been shown to elicit greater repetition duration, impulse, and total work (16) and higher peak and rate of muscle activation (66,131), there is a heightened possibility of residual fatigue, which can reduce force production postexercise (94). However, resistance training improves resistance to fatigue (22,23), and there is evidence to suggest that the training status can affect the magnitude of potentiation or fatigue following resistance exercise completed on the same day (21,22). In participants with a more extensive history of resistance training, isometric RFD was recovered to a greater degree 4-6 hours after a bout of fatiguing resistance exercise (22). ...
“Priming exercises” are gaining popularity as a precompetition strategy to improve subsequent performance. Although priming exercise has been shown to improve various neuromuscular performance measures within 48 hours, a number of studies have also found no change or significant decreases in performance following priming interventions. Inconsistencies in findings are likely due to the many different variables used in the research. In addition, evidence suggests that the potential performance response following a priming stimulus is likely to be influenced by individual characteristics. Therefore, the purpose of this review is to examine the available evidence and identify those variables that most strongly determine whether priming stimuli involving resistance and stretch-shortening cycle exercise tasks are likely to improve performance within 48 hours of that stimulus. In addition to making recommendations based on the evidence to date, directions for future research are also identified.
... Taking into consideration other variables such as sleep [10] and stress [11], the rate of recovery may dictate the readiness for the subsequent workout. Although less recovery time between each resistance training session (i.e., < 24 h between sessions vs. < 48-72 h between sessions) may not necessarily cause negative outcomes in muscle growth and strength within a short period of time (i.e., 12 weeks) [12], it has been suggested that improper post-exercise recovery or sequence of training may result in an increase in accumulated fatigue [13,14]. ...
... The concept of long-term fatigue accumulation has appeared repeatedly in the literature without clear elucidation of what is accumulating and how/why this is occurring [13][14][15][16][17][18][19]. Fatigue accumulation refers to the fatigue that summates over repeated bouts of training that is believed to be additive to pre-existing fatigue. ...
... Fitness after-effect causes a positive physiological response that increases performance, whereas fatigue after-effect causes a negative physiological response that adversely influences performance. The fitness gain resulting from training is suggested to be moderate in magnitude but long-lasting (i.e., increases in muscle strength), while the fatigue effect is large in magnitude with a brief duration (i.e., reduction in forcegenerating capacity) [14,21]. Consequently, the difference between these two antagonist effects is believed to describe performance and state of preparedness (preparedness = fitness − fatigue). ...
It has been suggested that improper post-exercise recovery or improper sequence of training may result in an ‘accumulation’ of fatigue. Despite this suggestion, there is a lack of clarity regarding which physiological mechanisms may be proposed to contribute to fatigue accumulation. The present paper explores the time course of the changes in various fatigue-related measures in order to understand how they may accumulate or lessen over time following an exercise bout or in the context of an exercise program. Regarding peripheral fatigue, the depletion of energy substrates and accumulation of metabolic byproducts has been demonstrated to occur following an acute bout of resistance training; however, peripheral accumulation and depletion appear unlikely candidates to accumulate over time. A number of mechanisms may contribute to the development of central fatigue, postulating the need for prolonged periods of recovery; however, a time course is difficult to determine and is dependent on which measurement is examined. In addition, it has not been demonstrated that central fatigue measures accumulate over time. A potential candidate that may be interpreted as accumulated fatigue is muscle damage, which shares similar characteristics (i.e., prolonged strength loss). Due to the delayed appearance of muscle damage, it may be interpreted as accumulated fatigue. Overall, evidence for the presence of fatigue accumulation with resistance training is equivocal, making it difficult to draw the conclusion that fatigue accumulates. Considerable work remains as to whether fatigue can accumulate over time. Future studies are warranted to elucidate potential mechanisms underlying the concept of fatigue accumulation.
... Wilson et al. (53) suggested that Banister Fitness Fatigue Model may sufficiently explain their findings as the greatest increases in batting performance were observed between 4 and 8 minutes. This model proposes that performance is a balance between fitness and fatigue, whereby changes to the former outlast those of the latter following recent contractile activity (23). This implies that maximal performance does not occur immediately following the training stimulus, thus explaining the delayed enhancement of performance following a weighted implement protocol as exhibited in the study of Wilson et al. (53). ...
... Postactivation potentiation is defined as the transient increase in short-duration contractile force capabilities of a high-velocity, short-duration competitive movement as a result of previous contractile activity of relatively higher intensity (27). This phenomenon has been suggested as the most appropriate physiological evidence of the acute effects of the fitness-fatigue model (23). Specifically, the realization of PAP is a function of the net balance between potentiation and fatigue, subsequent to the imposed conditioning activity (37). ...
... As verification of PAP requires observation of increased peak twitch force/torque and increased rate of twitch force/torque development, which are verified via electrical stimulation of single muscles/muscle groups (3,24,35), it may, however, be suggested that Banister model (23) and postactivation performance enhancement (PAPE) (35) are the most appropriate explanations of the acute effects of weighted implements based on the recommended mechanisms of the included studies. However, although these models may sufficiently explain reports of enhanced batting performance following a weighted bat warm-up in studies using a stationary target, the findings of studies assessing such effects when intercepting a dynamic target potentially diminish the efficacy of attaining such potentiated peripheral states. ...
Jermyn, S, Neill, CO, and Coughlan, EK. The acute effects from the use of weighted implements on skill enhancement in sport: A systematic review. J Strength Cond Res 35(10): 2922–2935, 2021—Weighted implements are used before competitive performance with the aim of enhancing motor skill execution on return to the standard implement. The purpose of this review was to analyze the existing literature pertaining to the acute effects of weighted implements on respective sporting performance. Following a systematic screening process, 25 studies were identified. This review highlighted the effects of (a) weighted balls and bats on throwing and batting performance and (b) indoor weight throw implements on indoor weight throw performance. Studies reported conflicting effects on immediate performance post–warm-up with the respective implements. Notably, although overweighted bats and overweight attachments are a prominent preparatory tool in baseball, this review found consistent and repeated evidence of degraded batting performance in striking-based studies. Decreased bat velocity, altered swing patterns, subjective-objective mismatches of bat speed and weight, temporal accuracy errors, and inadequate recalibration to the standard bat were identified as acute effects. This review identified an obvious dearth of research into the acute effects of weighted implements on motor skills in other sports with equally complex perceptual motor patterns, such as football (soccer), golf, rugby, basketball, and American football. Future weighted implement research should investigate the acute effects of respective implements on motor skill performance in other sports, such as those aforementioned, with the purpose of exploring relevant implications for preparatory strategies and immediate performance on return to the standard implement.
... Towards the end of this phase, the athlete's work capacity increases and reaches pre-conditioning levels and even surpasses the pre-conditioning level and reaches a climax. At the end of the cycle, the work capacity returns to pre-conditioning levels (Chiu & Barnes, 2003). Chiu and Barnes (2003:44) describe the general adaptation syndrome as "the initial response, the alarm stage, is negative, with the physiological state of the athlete decreasing following the imposition of stress. ...
... The fitness-fatigue theory, as defined by Zatsiorsky (1995) and depicted in Figure 2.5, describes the interrelationships between fitness, fatigue and preparedness. In theory, the result of every session or training cycle creates two physiological after-effects, namely fatigue and fitness, which combine to influence the athlete's level of preparedness and performance (Chiu & Barnes, 2003). This theory is in contrast to the GAS/supercompensation theory based on a cause-and-effect relationship between these factors. ...
... However, Bompa and Haff (2009) state that "fatigue dissipates at a more rapid rate than fitness, this means that the athletes state of preparedness is allowed to evelate and along with that the performance too." The physiological after-effects from training as described by Chiu and Barnes (2003) earlier are also refered to as residual training effects, which serve as the bases for most periodisation models. Specifically, the residual-effects from one training block has the ability to enhance the level of preparedness in the following training blocks as shown in Figure 2.5, depending on the periodisation models utilised in the design of the broader training plan (Haff & Haff, 2012). ...
An investigation into the effect of a block periodisation system in an elite olympic sprinter over the duration of three competitive seasons.
... (2014), en iyi ASPA yanıtının squat sonrası güçlü bireylerde 6. dakikada, zayıf bireylerde ise 9. dakikada oluştuğu bildirilmiştir. Güçlü bireylerin zayıf bireylere kıyasla yorgunluğa karşı daha hızlı toparlanma gerçekleştirmeleri, ASPA etkisinin güçlü bireylerde daha kısa sürede oluşmasının nedeni olarak açıklanabilmektedir (Chiu ve Barnes, 2003ve Hamada vd., 2000. Ayrıca ön yüklemeler sonrası sprint performansını inceleyen bir derlemede, %90 1 TM şiddetinde uygulanan squat ve power clean gibi direnç egzersizlerinin bireylerde sprint performansının artış gösterebilmesi için 4-8 dakikalık dinlenme süresi verilmesi gerektiği belirtilmektedir (Healy ve Comyns, 2017: 8). ...
... Bazı katılımcıların performansı artmış veya azalmışken, bazılarında herhangi bir farklılık tespit edilmemiştir (Lim ve Kong, 2013: 2734. Birçok çalışma bireylerin antrenman seviyesi, kronolojik yaş, antrenman yaşı, baskın kas lif tipi ve güç seviyelerinin farklılık göstermesinin ASPA'ya verilen bireysel cevapları etkileyebileceğini vurgulamıştır (Hamada vd., 2000;Chiu ve Barnes, 2003;Robbins, 2005 Bir motor beceri sergilendiğinde, performansın sonucu veya bu sonuca neyin neden olduğu hakkında iki genel bilgi türü (geri bildirim) vardır. Bunlardan biri beceriyi gerçekleştirmenin doğal parçası olan içsel geri bildirimdir. ...
İnsan türü evrimsel görüşe göre daha uzun alt uzuvlar, iki ayaklılık (bipedalizm), vücut boyutundaki ve metabolizmadaki değişiklikler ile yeni ekosistemde yiyecek arama ve hayatta kalma davranışını oldukça kolaylaştırmıştır. Bu nedenle, Afrika Homo erectusu olarak kabul edilen insan türünün en eski temsilcisi gerçekten de “koşmak için doğmuş (born to run)” sayılabilir. Yani önceki hominidlerin (büyük insansı maymun) yiyecek topladığı ormanlık alanlardan çarpıcı biçimde farklı bir ortamda doğal seçilim baskısı ile başa çıkmak (survival of the fittest: çevreye olan uyuma göre en iyinin hayatta kalması) için evrilmiş olabilir. Arkaik atalarımızın değişmiş kalça eklemi, daha hafif iskelet dahil olmak üzere çeşitli kas- iskelet sistemi adaptasyonları gibi anatomik değişiklikleri, vücutlarının dayanıklılık ve fiziksel aktivite için özelleşmesi yoluyla uzun mesafeler ve süreler boyunca yürümesine/ koşmasına izin vermiştir. Bu açıdan belki de türümüzün devamının bedensel hareket kabiliyetimize bağlı oluşu bizleri fiziksel hareketin doğasını keşfetmeye daha da meraklı hale getirmektedir. Nitekim bu doğrultuda yapılan güncel çalışmalar da aslında günümüzde sedanter yaşam tarzlarımızın bizlere getirdiği birçok hastalığa karşı tekrar türümüzü kurtaracak en etkili ve umut verici yöntemin düzenli egzersiz olduğunu göstermektedir. Bu yüzden bu kitapta yer alan tüm çalışmaların egzersiz bilincini topluma yaymak adına oldukça önemli olacağını düşünüyorum.
Mustafa Kemal Atatürk “Benim manevi mirasım ilim ve akıldır. Benden sonra, beni benimsemek isteyenler, bu temel mihver üzerinde akıl ve ilmin rehberliğini kabul ederlerse, manevi mirasçılarım olurlar. Bilim ve fen nerede ise oradan alacağız ve her ulus kişisinin kafasına koyacağız.” sözüyle bilimsel bilgiyi edinmenin ve yaymanın önemini vurgulamıştır. Nitekim bu manevi mirasa ortak olarak bu kitabın oluşturulmasına katkı sunan değerli yazarlarımıza teşekkürlerimi sunuyorum. Açıkçası bu süreçte birbirinden değerli ve güncel çalışmaların bir araya getirilmesini titizlikle sağlayan Eğitim Yayınevi ailesini de ayrıca tebrik etmek gerekiyor.
Son olarak her zaman koşulsuz şekilde yanımda olan sevgili aileme teşekkür ve minnetlerimi sunuyorum.
... 11 In addition, in the case of sports with one, two or even more weekly competitions, as in the case of indoor team sports, fatigue can accumulate with greater frequency and intensity. 12 On the other hand, the workload derived from training and development of the physical qualities that are decisive for the performance of the sport in question, can also induce additional levels of fatigue. 13 Therefore, monitoring the fatigue status of players in team sports is a topic of growing interest today. ...
... 13 Therefore, monitoring the fatigue status of players in team sports is a topic of growing interest today. 14,15 In a phenomenon as complex as fatigue, with a high number of interdependent variables of a diverse nature, 12,16 as well as individualized responses to the same training load, 17 it makes monitoring of fatigue must comprise a wide spectrum of parameters (mental, physical and emotional), to minimize injuries and illnesses. 11,18 Monitoring tools have been widely used as valid and reliable indicators for monitoring the recovery status of elite athletes, 19 allowing for greater efficacy in injury/illness prevention by prescribing training and recovery loads. ...
The aims of this study were: (1) to analyze how the periodization of workloads can induce states of accumulated fatigue in the short, medium and long term in indoor team sports and (2) to identify these periods of fatigue through the interpretation internal and external performance variables. This systematic review was carried out under PRISMA guidelines. The Web of Science, PubMed and Scopus databases were searched for relevant published studies between 1st January 2010 and 25th April 2021. The STROBE scale and MINORS checklist were used to assess the reporting and methodological risk of bias, respectively. Of the 2219 studies initially identified, 20 were selected for a full review. The main conclusions were that a periodic and integrative evaluation of monitoring variables of a different nature is needed to identify states of fatigue accurately and rigorously. The end of the preparatory periods (PPs) and the second phase of the competitive periods (CPs) seem to be the most exhausting moments of the season (high values of RPE, CK, LDH, and oxidative stress markers, and decrease in the T/C ratio). Specifically, congested weeks promote the development of high levels of acute and subacute fatigue (high levels of DOMS and fatigue along with low levels of RPE). Therefore, it is recommended to extend the duration of the preseason and the implementation of more active recovery days during congested weeks, in order to improve resistance to acute and subacute fatigue, and therefore avoid reaching a state of overtraining.
... The fitness-fatigue model has evolved to consider that there are more than one fitness and fatigue after-effects (Chiu & Barnes, 2003). Specific systems of the body such as the neuromuscular and cardiovascular system show unique fitness and fatigue after-effects from exercise training (Chiu & Barnes, 2003). ...
... The fitness-fatigue model has evolved to consider that there are more than one fitness and fatigue after-effects (Chiu & Barnes, 2003). Specific systems of the body such as the neuromuscular and cardiovascular system show unique fitness and fatigue after-effects from exercise training (Chiu & Barnes, 2003). In addition, there are inter-and intra-individual differences in the dose-response relationship of training and its associated "fitness" and "fatigue" (Morton, 1997). ...
Background: The popularity of endurance running events has rapidly increased in recent years with more recreational runners entering the field. How recreational runners train is not well known. Understanding this and the relationship between training and performance in this group of runners is important for prescribing appropriate training to maximise performance and decrease the risk of injury. This forms the underlying theme throughout this thesis.
Aim: The broad aims of this thesis were to better understand the ad libitum training habits of well-trained competitive recreational runners and to determine the relationships between performance, training load, and submaximal heart rate (HR) in this cohort.
Methods: Five inter-related studies were performed to: 1) determine relationships between 56-km race performance and pacing (n = 7,327) in competitive recreational runners; 2) determine relationships between 56-km race performance, pacing, and training load in competitive recreational runners (n = 69); 3) determine the accuracy of GPS sport watches in measuring distance (n = 255); 4) develop a feasible and reliable submaximal running test, and 5) determine relationships between performance on a submaximal running test, training load, and submaximal HR in well-trained competitive recreational runners (n = 29).
Main findings: A group of well-trained competitive recreational runners performed 44 22 km/week (median IQR) in a six-month time frame while training ad libitum. This group had a wide range of inter-individual differences in training load performed even when considering participants who had the same relative marathon performance. The same group of well-trained competitive recreational runners maintained most of their training over a six-month period in a range of 0.81 – 1.14 for the acute: chronic workload ratio (ACWR). When the ACWR values reached > 1.50, it was mainly due to participation in endurance running races (> 21-km). When looking at relative weekly changes in training load, the maximum increase was 30% with only two participants having maximum increases of < 10%. The increases in load were predominantly short term (one to two weeks). Submaximal HR had a negative linear relationship with performance in 21% of the study participants. In those participants, poor performances were associated with a higher submaximal HR. Training load was only related to changes in performance in one participant.
Conclusion: This thesis confirms that no single variable can provide the necessary information on how to adjust training load to maximise performance. Athletes, coaches, and sports scientists need to have a holistic view of stress exposure and how this affects the body. Although we can only speculate, when the participants had a poor performance it may have been due to factors such as lack of motivation, fatigue, mental stress, dehydration, and/or sleep deprivation. It is important for runners, coaches, and sports scientists to approach the training load – recovery balance as being unique for each athlete. Even in a homogenous group of well-trained competitive recreational runners, their ad libitum training load is widely varied and was not associated with performance or ability level. The balance should be adjusted over time based on the athlete’s symptoms.
... A climber`s potential performance known as climbing readiness varies in time. The prevalent theory of training and adaptation is based on the Fitness-Fatigue paradigm (Chiu and Barnes, 2003;Zatsiorski and Kraemer, 2006) stating that the athlete`s readiness can be measured with the primary after-effects of training: fitness and fatigue. Physical fitness is a slow-changing motor component that remains relatively stable over several hours or even days, but fatigue or psychological overstress can quickly change a climber`s disposition toward leading a climbing route. ...
... Strategies maximizing fitness and minimizing fatigue have the greatest potential to optimize athlete`s readiness (Zatsiorski and Kraemer, 2006). The Fitness-Fatigue paradigm differentiates between the impact of various stressors that induce different neuromuscular and metabolic stress responses (Chiu and Barnes, 2003). ...
The aim of this study was to determine changes in climbers’ hormonal, cardiovascular, neuromuscular, sleep and fatigue status, and their relationship with performance and workloads during a sport rock climbing camp. Mean difficulty of individual leading climbing routes (mean Difficulty) was calculated for six male, intermediate level sport rock climbers participating in a 2-week camp in Orpierre. Additionally, each morning climbers were tested for: cortisol (d-Cortisol) and testosterone (d-Testosterone) concentrations, testosterone/cortisol ratio (T/C), heart rate and heart rate variability in supine (d-L-HR, d-L-SD1, d-L-SD2) and standing positions (d-S-HR, d-S-SD1, d-S-SD2), difference in S-HR and L-HR (HR-S-L), maximal voluntary hand grip strength (MVC), sleep duration (Sleep) and the self-perception of fatigue (M-Fatigue). Only M-Fatigue and d-Testosterone did not change significantly during the camp. Changes in other variables were large and significant, especially in the second week of the camp when the mean Difficulty was > 70%. The greatest changes were noted on the last day, when T/C, HR-S-L, and Sleep decreased and d-Cortisol, d-L-HR, and d-SD1 increased. The monitoring of the uncoupling of neuromuscular, hormonal, and cardiovascular markers can be instrumental in determining the level of athletes’ morning fatigue and readiness during a climbing camp. An increase in d-Cortisol and a decrease in T/C and HR-S-L are relevant indicators of overreaching in sport climbers.
... This is accompanied by altered stride parameters (e.g., increased contact time and stride duration, reduced stride frequency and length) and, ultimately, slower sprint times (14,52). While fatigue can be important for adaptation (27), adopting programming strategies to help maintain mechanical efficiency during RST could enhance sprint performance. ...
Repeated-sprint training (RST) involves maximal-effort, short-duration sprints (≤10 seconds) interspersed with brief (≤60 seconds) recovery periods. It can enhance a range of physical qualities to help prepare intermittent sport athletes for the high-intensity demands of competition. This review provides a scientific basis for applying running-based RST with intermittent sport athletes. The acute and chronic responses to RST are reviewed, as well as the manipulation of programming variables to target specific training outcomes (i.e., sprint modality, number of repetitions and sets, repetition distance, rest time, rest modality, volume, training frequency, and program duration). Furthermore, practical considerations for an individualized approach to RST and an applied framework for how and when it can be best integrated into the annual training program are presented.
... While the current study did not evaluate physiological parameters, it is worth noting that previous research indicates that the differences seen may be largely attributed to enhanced fatigue resistance and improved muscle contractile properties [32,33]. Less fatigability following resistance training seems to be a result of muscle angiogenesis [32]. ...
This study aimed to determine the effect of complex training (CT) on post-activation performance enhancement (PAPE) effect magnitude, 5- and 30-m linear sprint, 5-0-5 change-of-direction (COD), back squat (BS) and hip thrust (HT) one-repetition maximum [1RM], and jumping performance (countermovement jump [CMJ], drop jump [DJ], and broad jump [BJ]). The PAPE effect was elicited before and after each intervention by 3 BS repetitions at 90% 1RM and verified by CMJ performance. Twenty-four soccer players were randomly and equally assigned to 6 weeks of either medium (MED; [65–70%1RM]) or high-intensity (HIGH; [80–85%1RM]) CT performed twice a week. The HIGH group significantly improved their 5-m time (p < 0.001; effect size [ES] = 1.91), 30-m time (p = 0.001; ES = 0.66), BS 1RM (p = 0.019; ES = 0.19) and HT 1RM (p = 0.035; ES = 0.26), BJ length (p = 0.012; ES = 0.62) and DJ height (p = 0.002; ES = 0.57) from pre- to post-intervention. The MED group significantly improved their 5-m time (p = 0.004; ES = 0.52), BS 1RM (p = 0.019; ES = 0.36) and BJ length (p = 0.012; ES = 0.7). Significantly shorter 5-m sprint time (p = 0.001; ES = 1.63) and greater DJ height percentage increase (p < 0.001; ES = 1.81) were found in the HIGH group compared to the MED group. Moreover, a significant main effect of the group, indicating a higher PAPE response in the MED group compared to the HIGH group for CMJ peak power output, was observed at both pre- and post-CT intervention (p = 0.045; η2 = 0.171). Six weeks of either medium or high-intensity CT could be used to enhance jumping performance, linear speed and lower-body maximum strength among soccer players. Superior improvements in acceleration and DJ might be expected after high-intensity CT than medium intensity. Medium-intensity CT can improve PAPE response.
... Collectively, these findings indicate the importance of the volume of plyometric CA as it might cause either potentiation or fatigue (Hanson, Leigh & Mynark, 2007;Khamoui et al., 2009 There are several other factors that can influence the effect of PAPE. Studies have indicated that recovery times following CA may impact the PAPE response, and that these optimal rest intervals may also depend on the strength level of individuals (Hamada, Sale, Macdougall & Tarnopolsky, 2000;Chiu & Barnes, 2003;Seitz & Haff, 2016;Blazevich & Babault, 2019). It is likely that why the multi-set CA (3 x 10 reps) in this research was unable to improve jump performance was attributable to the short recovery time after CA. ...
Post-activation performance enhancement is a principle that suggests that an acute bout of high intensity voluntary exercise will be followed by an improvement in strength, power, jump and speed of a subsequent task. This study aimed to investigate changes in 15 s repetitive vertical jump performance after one set (1 x 10 repetitions) or three sets (3 x 10 repetitions) of tuck jumps conditioning activity. Twelve male (age 21.6 ± 1.5 years) trained volleyball players participated in this study. The participants performed three experimental sessions with a randomized, counterbalanced, and crossover research design: a-) single set of tuck jump (SJ); b-) multiset of tuck jump (MJ); and c-) control (CON). Each experimental session was composed of a standard warm-up, conditioning activity, 5 minutes of rest, and then 15 s vertical jump test, respectively. Peak (p=0.029) and average (p=0.018) jump height, peak (p=0.029) and average (p = 0.007) power output were significantly greater in SJ than CON. No significant differences were observed in the fatigue index between conditions (p=0.657). Overall, there were no significant differences in any parameters between MJ and CON and between SJ and MJ (p>0.05). These results showed that a SJ could improve repetitive vertical jump performance in trained male volleyball players, but caution should be given while using MJ before trainings or matches including activities with repetitive jumping.
... In a fitness-fatigue model, muscle strength and power improved once the development of muscle potentiation after high-intensity conditioning activities outweighed the development of fatigue [27]. Therefore, an ideal conditioning activity should facilitate the development of potentiation while avoiding the rapid development of fatigue. ...
This study investigated the effect of different resistance increments during warm-up on snatch performance of male weightlifters. Nine male college weightlifters were recruited. The 3 warm-up protocols were performed every 7 days with a randomized order: 1. Power snatch exercise with 10 % resistance increment (50 %, 60 %, 70 %, and 80 % of one-repetition maximum); 2. Power snatch exercise with 15 % resistance increment (50 %, 65 %, and 80 % of one-repetition maximum); 3. Self-selected resistance increment. Participants were tested based on 85 % maximum weight snatch after warm-up. Snatch performance was measured using peak vertical ground reaction force. Postural stability was measured using center-of-pressure displacement. Activation of seven shoulder, back, and leg muscles was measured using electromyography on the dominant side. In snatch performance, the 10 % increment protocol had a significantly higher peak vertical ground reaction force during the second-pull phase than the 15 % increment (d = 0.92, p < 0.05) and self-selected (d = 1.32, p < 0.05) protocols. In postural stability, no significant differences in center-of-pressure displacement among the three protocols were observed. For muscle activation, the 10 % increment protocol resulted in significantly higher activation of shoulder (d = 1.2–2.2, p < 0.05) during the second-pull phase than the other two protocols and higher activation of hip muscles (d = 1.73, p < 0.05) than self-selected protocol. To conclude, a warm-up protocol combining slow progression is preferable in improving power output during snatch in male weightlifters, probably through facilitating the activation of proximal limb muscles. It can enhance training quality while potentially reducing the risk of sports injuries.
... This type of model is also commonly referred to as an impulse-response model, which is based on observing the organism's response to a perturbation in homeostasis caused by the impulse (training load) within a specific time frame. Bannister's original model also assumes only two contrasting factors that start their after-effects at the end of the training session, which has been considered misleading by a revised version considering multiple fitness and fatigue after-effects [37]. It is also argued that while the maximal value of fatigue after-effects is taken immediately after the session, the fitness after-effects are known to be progressive, continuing from the end of the session [38]. ...
This study examined the impact of training load periodization on neuromuscular readiness in elite football players using the Locomotor Efficiency Index (LEI) as a measure of performance optimization. Throughout the 2021/22 and 2022/23 seasons, 106 elite male players (age: 19.5 ± 3.9 years) from an Italian professional football club were monitored using Global Positioning Systems (GPS) external load data. The LEI was derived from a machine learning model, specifically random forest regression, which compared predicted and actual PlayerLoad™ values to evaluate neuromuscular efficiency. Players were categorized by weekly LEI into three readiness states: bad, normal, and good. Analysis focused on the variation in weekly LEI relative to weekly load percentage variation (large decrease, moderate decrease, no variation, moderate increase, large increase), which included total distance, high-speed distance (above 25.2 km/h), and mechanical load, defined as the sum of accelerations and decelerations. Statistical analysis showed significant differences only with variations in total distance and mechanical load. Specifically, reducing weekly loads improved LEI in players in lower readiness states, while maintaining or slightly increasing loads promoted optimal readiness. This approach enables coaches to tailor training prescriptions more effectively, optimizing workload and recovery to sustain player performance throughout a demanding season.
... A importância da organização e estruturação do treinamento esportivo torna-se fundamental no sentido de fazer com que os atletas alcancem seu melhor desempenho, principalmente durante o período competitivo 1,2 . Assim, é necessário um monitoramento preciso das cargas de treinamento para identificar se os atletas estão se adaptando ao programa de treinamento planejado e para evitar as adaptações negativas, como lesões, doenças e overreaching não-funcional1. ...
O presente estudo buscou investigar o efeito da frequência de jogos na distribuição das cargas de treinamento e do estado de recuperação em diferentes tipos de treinamento, e a variabilidade das cargas através da razão da carga de trabalho agudo-crônica durante o período competitivo de uma equipe profissional de voleibol. Participaram deste estudo 13 atletas profissionais do voleibol masculino (21,5 ± 1,8 anos, 90,9 ± 8,0 kg e 196 ± 7 cm). A Carga de Treinamento Semanal Total (CTST) foi calculada pela soma das cargas internas de treinamento da semana. Também foi calculada a razão da carga de trabalho agudo-crônica (ACWR) para cada jogador pela razão entre a CTST da semana pela CTST média das últimas quatro semanas. O estado de recuperação foi medido no início (TQR inicial) e no final da semana (TQR final). A CTST média da temporada competitiva foi de 3606 ± 970 U.A., a TQR média inicial e final foi de 14,8 ± 1,4 e 13,5 ± 0,8 U.A., respectivamente. Houve redução na CTST das sessões de treino de força e de quadra conforme aumentou a frequência de jogos na semana (p< 0,05). Houve diminuição da TQR inicial com o aumento do número de jogos por semana (p< 0,05). Em adição, a TQR final foi maior na semana com um jogo em comparação com a semana com dois jogos. Em relação a ACWR, 75% das sessões de treino ficaram dentro da zona de segurança recomendada (0,8 a 1,3). Portanto, a ACWR se mostrou uma ferramenta sensível para avaliação individualizada da carga de treino durante o período competitivo de uma equipe profissional de voleibol. Em adição sugere-se a análise da carga de treino e do estado de recuperação de acordo com a frequência de jogos e o tipo de treino realizado para melhor compreensão dos estímulos de treino.
... According to classical training theory, physical training results in a transient reduction in performance (often simply referred to as "fatigue"), which is followed by a delayed performance improvement as a result of positive physiological adaptations to the training stimulus (Chiu and Barnes 2003;Bompa and Haff 2009). Since the early work of Banister et al. (1975), it has been theorized that following a single training session, both the acute decrements and subsequent improvements in performance are proportional to the magnitude of the training load, or "impulse", a term often used to describe the training "dose" of a single session. ...
Classical training theory postulates that performance fatigability following a training session should be proportional to the total work done (TWD); however, this notion has been questioned. This study investigated indices of performance and perceived fatigability after primary sessions of high-intensity interval training (HIIT) and constant work rate (CWR) cycling, each followed by a cycling time-to-task failure (TTF) bout. On separate days, 16 participants completed an incremental cycling test, and, in a randomized order, (i) a TTF trial at 80% of peak power output (PPO), (ii) an HIIT session, and (iii) a CWR session, both of which were immediately followed by a TTF trial at 80% PPO. Central and peripheral aspects of performance fatigability were measured using interpolated twitch technique, and perceptual measures were assessed prior to and following the HIIT and CWR trials, and again following the TTF trial. Despite TWD being less following HIIT (P = 0.029), subsequent TTF trial was an average of 125 s shorter following HIIT versus CWR (P < 0.001), and this was accompanied by greater impairments in voluntary and electrically evoked forces (P < 0.001), as well as exacerbated perceptual measures (P < 0.001); however, there were no differences in any fatigue measure following the TTF trial (P ≥ 0.149). There were strong correlations between the decline in TTF and indices of peripheral (r = 0.70) and perceived fatigability (r ≥ 0.80) measured at the end of HIIT and CWR. These results underscore the dissociation between TWD and performance fatigability and highlight the importance of peripheral components of fatigability in limiting endurance performance during high-intensity cycling exercise.
... Coaches are advised to introduce the load progressively and, in the middle of the pre-season period, decrease the training loads to allow recovery and better balance the fitness-fatigue relationship [67]. In fact, elevated injury rates have been observed during this period in other sports [68]. ...
Background
Volleyball, with its unique calendar structure, presents distinct challenges in training and competition scheduling. Like many team sports, volleyball features an unconventional schedule with brief off-season and pre-season phases, juxtaposed against an extensive in-season phase characterized by a high density of matches and training. This compact calendar necessitates careful management of training loads and recovery periods. The effectiveness of this management is a critical factor, influencing the overall performance and success of volleyball teams. In this review, we explore the associations between training stress measures, fatigue, and well-being assessments within this context, to better inform future research and practice.
Methods
A systematic literature search was conducted in databases including PsycINFO, MEDLINE/PubMed, SPORTDiscus, Web of Science, and Scopus. Inclusion criteria were original research papers published in peer-reviewed journals involving volleyball athletes.
Results
Of the 2535 studies identified, 31 were thoroughly analysed. From these 31 articles, 22 included professional athletes, seven included collegiate-level volleyball athletes, and two included young athletes. Nine studies had female volleyball players, while the remaining 22 had male volleyball athletes.
Conclusions
Internal training load should be collected daily after training sessions and matches with the session rating of perceived exertion method. External training load should also be measured daily according to the methods based on jump height, jump count, and kinetic energy. If force platforms are available, neuromuscular fatigue can be assessed weekly using the FT:CT ratio of a countermovement jump or, in cases where force platforms are not available, the average jump height can also be used. Finally, the Hooper Index has been shown to be a measure of overall wellness, fatigue, stress, muscle soreness, mood, and sleep quality in volleyball when used daily.
... In this context, optimisation of physical capacities is of crucial importance. Therefore, this topic is well-studied with much scientific research focusing on construction of balanced training schemes (Chiu & Bradford, 2003), finding the right nutrition (Beck et al., 2015), and identifying proper genetic endowment (Guth & Roth, 2013). Moreover, recent technological developments and advances in machine learning opened up new promising directions for detailed athlete monitoring and further optimisation physical performance in road cycling Hilmkil et al., 2018;Karetnikov et al., 2021). ...
We investigate the relationships between age and race performance in women’s road cycling. Therefore, we consider public data from ProCyclingStats (PCS) on race results of 558 female riders present in the top 500 of one of the yearly rankings between 1993 and 2021. We apply a data-driven approach consisting of three subsequent steps. First, we train decision tree classifiers to distinguish between race profiles. Second, we cluster the riders based on the fraction of PCS points obtained in different race types and uniquely identified the speciality of a rider as Sprinter, All Rounder or One Day. Third, we use polynomial
regression to determine relationships between age and a rider’s yearly race performance, defined as the average number of points per race entered in a single year, for each cluster. We obtain that the yearly performance is independent of age for one-day specialists. For sprinters and all-rounders, we found that the race performance increases until it reaches a maximum at 28.7 (sprinters) and 27.0 (all-rounders) years and then decreases again. Our findings can be used as a benchmarking tool for monitoring the development of women’s road cyclists, talent identification or constructing long-term training programmes.
... Within the context of sports, adaptation to training is reflective of the organisms' (in this scenario the athlete as the system) ability to adjust and adapt to the stimuli that disrupts homeostasis throughout the training process and the systems' ability to return to homeostasis (recover for the next stimuli) (Chiu & Barnes, 2003;Cunanan et al., 2018;Plisk & Stone, 2003;Selye, 1956). A negative trend in adaptations may indicate, and result, in an overall residual fatigue state that without sufficient recovery, over a prolonged period, may contribute to injuries, illness, and reduced performance leading to overreaching and in severe cases overtraining (Edwards, 2018;Thorpe et al., 2017). ...
As the demands of training and competition increase so does the potential risk of injury and illness to the athlete whilst seeking to maximize their adaptive processes to promote optimal performance. Therefore, as a strategy to mitigate this risk, strength and conditioning coaches need reliable and valid monitoring tools to track an athlete's status throughout training to ensure the progression of adaptation, and that the athlete remains healthy throughout the adaptation process. The purpose of this article is to provide the reader with an evidence-driven outline of basic, simple, and cost-effective monitoring tools that are reliable and valid to observe the fitness/fatigue paradigm and track overall athlete physical adaptation and health throughout the training process, suitable for most settings. A weekly example calculating sessional ratings of perceived exertion (sRPE), training load, monotony, and strain is provided along with a basic monitoring system as a guide for the reader.
... Findings show that positive and negative responses to different perceptual measures may be expected approximately 3 hours after completing upper-body priming exercise. These can be likened to the fitness-fatigue model, in which performance is determined by the interaction of fitness (positive) and fatigue (negative) factors (3). Within this context, negative changes to perceived muscular heaviness and recovery after 3 hours seem to be opposed by other positive responses in perceived aggression and physical state. ...
Harrison, PW, Kelly, VG, Jenkins, DG, McGuigan, MR, Holmberg, PM, and James, LP. Does moderate-load priming activity influence maximal upper-body performance and perceptual state?. J Strength Cond Res 37(11): e581–e587, 2023—The results of previous research indicate that resistance exercise “priming” may improve strength-power measures within 48 hours after their completion. Although researchers have primarily examined performance responses after lower-body priming stimuli, investigations examining the effects of upper-body resistance priming exercises are presently limited. Therefore, the aim of this study was to examine upper-body pushing and pulling performance in addition to perceptual responses 3 and 27 hours after moderate-load (ML) upper-body resistance priming exercise. Fourteen resistance-trained men were assigned to complete ML priming (4 × 3 bench press and bench pull at 65% 1RM [repetition maximum]) and control (rest) protocols in a randomized and counterbalanced order. Peak velocity during the bench throw and bench pull tests involving different loads (25, 50, and 75% 1RM) showed no practical change at 3 and 27 hours after the priming session ( p = 0.216–0.99, Cliff's d = −0.041 to 0.225). Small effect size increases in perceptual measures (“physical feeling,” “physical performance,” “aggression” [ p = 0.400–0.553, Cliff's d = 0.183–0.201], and “muscular heaviness” [ p = 0.178, Cliff's d = 0.231]) were found at 3 hours postpriming. A moderate practical increase was observed in perceived “physical feeling” compared with control ( p = 0.385, Cliff's d = 0.349) in addition to small effect size increases in perceived “physical performance” and “aggression” (Cliff's d = 0.243–0.290) at 27 hours after priming activities. These results indicate that upper-body strength-power changes within 27 hours after ML upper-body resistance exercise priming are not practically meaningful.
... Restoration was accompanied by a trend of potential improvement in CMJ-TYP output variables (Figure 3). According to the fitness-fatigue model, exercise stress induces positive and negative responses, fitness and fatigue after effect, respectively, and as the duration of the fitness after effect persists longer than the fatigue after effect, the performance remains high while fatigue is diminished (8). Acute fitness after effects seems to be primarily related to neural factors, including optimization of magnitude and rate of activation of the neuromuscular complex, coactivation of intrafusal fibers, and decreased autogenic inhibition (35,36). ...
Yoshida, N, Hornsby, WG, Sole, CJ, Sato, K, and Stone, MH. Effect of neuromuscular fatigue on the countermovement jump characteristics: basketball related high-intensity exercises. J Strength Cond Res XX(X): 000-000, 2023-The purpose of this study was to investigate basketball specific neuromuscular (NM) fatigue effect on countermovement jump (CMJ) force-time (F-T) curve characteristics. Eleven male college-level basketball athletes performed 6 CMJ trials at 3 baseline (pre) and 6 postexercise time points. The fatiguing protocol consisted of high-intensity basketball related exercises commensurate with basketball game or practice. Typical CMJ (CMJ-TYP) and phase-specific CMJ variables were derived from the F-T curve. Meaningful differences in CMJ performance were examined using effect size (ES) compared with baseline and previous postexercise time point. Baseline with 3 separated measurements demonstrated suitable CMJ variables reproducibility (CV, coefficient of variation). Most CMJ-TYP output and performance variables displayed substantial alterations immediately postexercise (0 hour) and returned to baseline at 24 hours postexercise, whereas the time and rate-related CMJ-TYP and CMJ-phase variables tended to display delayed decline peaked at 2 hours and delayed recovery to baseline at 48 hours postexercise. In conjunction with the return of the time and rate-related variables, CMJ performance displayed supercompensation at 72 hours postexercise. The results indicate altered NM functions with desired CMJ performance, such as jump height, which imply an altered movement strategy at early stage of recovery process. Full recovery may take 48-72 hours. Practitioners are, therefore, advised to monitor variables reflecting NM functions for precise manipulation of the intensity and volume of exercise to avoid prolonging the recovery from NM fatigue.
... where the experienced stress is greater than the organisms ability to adapt (Chiu and Barnes, 2003). This basic theoretical model was the basis for Banister's Fitness-Fatigue model (Banister et al., 1975). ...
... impairment in the muscles ability to produce force) imposed by RST, with considerable decrements in CMJ height observed immediately after its implementation. However, while fatigue may be detrimental to acute performance, it also can be important for adaptation [85]. ...
Background
Repeated-sprint training (RST) involves maximal-effort, short-duration sprints (≤ 10 s) interspersed with brief recovery periods (≤ 60 s). Knowledge about the acute demands of RST and the influence of programming variables has implications for training prescription.
Objectives
To investigate the physiological, neuromuscular, perceptual and performance demands of RST, while also examining the moderating effects of programming variables (sprint modality, number of repetitions per set, sprint repetition distance, inter-repetition rest modality and inter-repetition rest duration) on these outcomes.
Methods
The databases Pubmed, SPORTDiscus, MEDLINE and Scopus were searched for original research articles investigating overground running RST in team sport athletes ≥ 16 years. Eligible data were analysed using multi-level mixed effects meta-analysis, with meta-regression performed on outcomes with ~ 50 samples (10 per moderator) to examine the influence of programming factors. Effects were evaluated based on coverage of their confidence (compatibility) limits (CL) against elected thresholds of practical importance.
Results
From 908 data samples nested within 176 studies eligible for meta-analysis, the pooled effects (± 90% CL) of RST were as follows: average heart rate (HRavg) of 163 ± 9 bpm, peak heart rate (HRpeak) of 182 ± 3 bpm, average oxygen consumption of 42.4 ± 10.1 mL·kg⁻¹·min⁻¹, end-set blood lactate concentration (B[La]) of 10.7 ± 0.6 mmol·L⁻¹, deciMax session ratings of perceived exertion (sRPE) of 6.5 ± 0.5 au, average sprint time (Savg) of 5.57 ± 0.26 s, best sprint time (Sbest) of 5.52 ± 0.27 s and percentage sprint decrement (Sdec) of 5.0 ± 0.3%. When compared with a reference protocol of 6 × 30 m straight-line sprints with 20 s passive inter-repetition rest, shuttle-based sprints were associated with a substantial increase in repetition time (Savg: 1.42 ± 0.11 s, Sbest: 1.55 ± 0.13 s), whereas the effect on sRPE was trivial (0.6 ± 0.9 au). Performing two more repetitions per set had a trivial effect on HRpeak (0.8 ± 1.0 bpm), B[La] (0.3 ± 0.2 mmol·L⁻¹), sRPE (0.2 ± 0.2 au), Savg (0.01 ± 0.03) and Sdec (0.4; ± 0.2%). Sprinting 10 m further per repetition was associated with a substantial increase in B[La] (2.7; ± 0.7 mmol·L⁻¹) and Sdec (1.7 ± 0.4%), whereas the effect on sRPE was trivial (0.7 ± 0.6). Resting for 10 s longer between repetitions was associated with a substantial reduction in B[La] (−1.1 ± 0.5 mmol·L⁻¹), Savg (−0.09 ± 0.06 s) and Sdec (−1.4 ± 0.4%), while the effects on HRpeak (−0.7 ± 1.8 bpm) and sRPE (−0.5 ± 0.5 au) were trivial. All other moderating effects were compatible with both trivial and substantial effects [i.e. equal coverage of the confidence interval (CI) across a trivial and a substantial region in only one direction], or inconclusive (i.e. the CI spanned across substantial and trivial regions in both positive and negative directions).
Conclusions
The physiological, neuromuscular, perceptual and performance demands of RST are substantial, with some of these outcomes moderated by the manipulation of programming variables. To amplify physiological demands and performance decrement, longer sprint distances (> 30 m) and shorter, inter-repetition rest (≤ 20 s) are recommended. Alternatively, to mitigate fatigue and enhance acute sprint performance, shorter sprint distances (e.g. 15–25 m) with longer, passive inter-repetition rest (≥ 30 s) are recommended.
... 55 It is suggested that the greater the duration of the training phase, the longer adaptations will last, and with a greater resistance to detraining. 68 The Fit-Fat model (Figure 3) is currently a popular concept of recovery-adaptation 11,43,68 that considers sport preparedness. The characteristic of sports preparedness deals with the degree to which an athlete is ready to perform. ...
... For example, the realization and translation of these adaptations into positive competition performances are also required for success. They have been expressed throughout various concepts such as the fitness-fatigue model (19) and tapering strategies (12), among others, that discuss or aim to facilitate athlete readiness and preparedness on the day of competition (43). However, this article highlights and discusses acute (single-session) exercise-based strategies commencing several days until minutes before competition and their potential performanceenhancing effect(s). ...
Athletes engage in training programs that develop physical and physiological
attributes to improve performance over time. However, ensuring athletes are
optimally prepared just before competition is also of utmost importance. Indeed,
such approaches may often adopt 1 or more strategies in the days, hours,
and minutes preceding competition, including exercise priming, active warmup, and/or postactivation performance enhancing (PAPE) activities. Despite a plethora of discrete research, such information seems poorly synthesized, making it difficult for coaches and athletes to implement optimal evidence based physical preparation approaches in many sporting contexts. This article aims to provide a scoping overview of evidence, facilitate discussion, and where possible, propose practical exercise based recommendations that may be useful leading up to (;48 hours–;
1 minute) tasks with a short or prolonged endurance component or requiring
repeated intermittent efforts (e.g., team based field sports). Well-timed and -designed activities can facilitate several aspects of physical performance, potentially improve athletes’ psychological state(s) and mental preparedness. The
benefits of a warm-up are most well documented, but priming and PAPE
strategies also warrant consideration. It is intended that the evidence and suggestions presented will be useful for strength and conditioning professionals preparing athletes for competition.
... Igualmente, es necesario mencionar que las respuestas a los protocolos de potenciación post activación están ligadas a las características individuales de los participantes (Sanchez-Sanchez et al., 2018), por lo que también se podrían encontrar casos de sujetos "no-respondedores" a pesar de aplicar el protocolo en mención. Por lo tanto, se debe tener en cuenta que la respuesta individual puede variar acorde a la duración de tiempo para la recuperación (Hamada et al., 2000;Chiu & Barnes, 2003) y los niveles de fuerza del deportista (Seitz & Haff, 2016). En consecuencia, se requiere un enfoque más personalizado para establecer las dosis de precarga "óptimas", así como el tiempo de descanso más adecuado para poder aprovechar la máxima aplicación de la post-activación en la planificación deportiva (Sari et al., 2022). ...
En esta investigación se presentan los resultados sobre los efectos agudos de dos protocolos de Potenciación Post-Activación a partir del salto sobre la agilidad de jugadores de balonmano colombianos. Metodología: estudio cuantitativo con diseño pretest y post test, en el que participaron 16 jugadores y 14 jugadoras de balonmano distribuidos bajo aleatorización simple en 3 grupos: Potenciación post-activación con saltos verticales (PPAV), Potenciación postactivación con saltos horizontales (PPAH) y control (CTRL). Resultados: Se encontraron efectos triviales en hombres para PPAV (TE = 0,05) y PPAH (TE = 0,02), y en las mujeres se obtuvieron efectos bajos para PPAH (TE = 0,41) y PPAV (TE= 0,23). No se evidenciaron mejoras en CTRL en hombres ni mujeres. Conclusión: los protocolos de salto vertical y salto horizontal implementados en este estudio influencian de forma positiva la agilidad en hombres y mujeres colombianas practicantes de balonmano.
... Periodization modulates training loads via daily, weekly, or monthly alterations in training load, frequency, repetition scheme, and/ or exercise variation to potentially enhance strength adaptation [2], [3]. The two main guiding principles of training prescription have been developed utilizing two theories of adaptation and performance: the Selye general adaptation syndrome [4] and the fitness-fatigue theory [5]. The final block of training is considered the peaking block and is comprised of two phases: (a) overreaching and (b) taper. ...
Powerlifting competition is comprised of three barbell lifts: squat, bench press, and deadlift that are all completed in a single day and summed together, ultimately normalized to the lifter’s body weight via the Wilks Coefficient. This figure is then subsequently employed to determine the “best” athlete in that meet. During the competition preparation, powerlifters often undergo peaking protocols which include physiologically taxing overreach and low-volume, recovery-focused taper phases to collectively induce super-compensatory strength adaptations. Heart rate variability (HRV) has emerged as an easily accessible, user-friendly biomarker for autonomic nervous system-associated fatigue and readiness. Therefore, the purpose of this observational study was to investigate the potential impact of a peaking protocol on fatigue/readiness via HRV measurements and its possible relationship with competitive powerlifting performance. Daily measurements of HRV were taken, each morning, using the HRV4Trainning smartphone application by nineteen competitive powerlifters (26.16±4.56 years) from 14-days prior to a peaking protocol, throughout individual peaking phases, on meet day, and 14-
days following competition. A quadratic regression was used to determine the predictability of HRV measurements and powerlifting performance. The change in HRV from competition day to baseline was found to be a significant predictor of Wilks coefficient (p=0.038, R2=0.336; mean±SE log- transformed root mean square of successive R-R intervals [lnRMSSD] = -51.98±22.23). Although extrapolations of the present study are limited by inherent subject peaking protocol variability, these data suggest HRV may nonetheless represent a viable means to modulate individual athlete training programs to promote recovery.
... O'Leary, Collett, Howells, et al. [29] investigated the effects of a 6-week cycling training program on neuromuscular function, and despite finding a decrease in the voluntary activation after the time to exhaustion tests, these values did not also change along the 6 weeks. These findings indicate that the fatigue after-effects did not occur at post-training period, due to possible central adaptations induced by training as attenuated cerebral ammonia uptake, enhanced spinal reflex excitability, improved handling of serotonin and cerebral oxygenation, and higher resistance to the central inhibitory effects of group III/IV afferent firing [29,30]. ...
This study aimed to investigate the effects of 6-week specific preparatory period and 2-week taper period on neuromuscular fatigue profile in 100-m front crawl swimming performance. Seventeen competitive-level young-adult swimmers performed a 100-m swimming performance at baseline and after 6-week specific preparatory followed by 2-week taper periods. Neuromuscular fatigue profile was assessed through percutaneous electrical stimuli on the femoral nerve during a maximal voluntary contraction performed before and immediately after each 100-m maximal effort. Performance improved (p = 0.001) 2.24 and 3.06 % after specific and taper, respectively. Potentiated peak force at post-effort condition decreased (p < 0.001) 16.26 % at baseline, 11.70 % at specific, and 12.86 % at taper period. Maximal voluntary contraction force also decreased (p < 0.001) at post-effort condition by about 6.77 and 9.33 % at baseline and specific period, respectively. Both variables did not present significant differences between times. No condition or time effects were observed to superimposed peak force and voluntary activation, both related to central fatigue. In conclusion, neuromuscular fatigue during 100-m swimming performance was exclusively developed by peripheral mechanisms regardless of the training period, and 2-week taper was able to prevent decreases in maximal voluntary contraction induced by 100-m maximal effort.
... The enhancement of muscular strength, muscular power and performance variables associated with these physical traits are suggested to occur as a result of CT taking advantage of a physiological event known as post-activation potentiation (PAP) (Jones et al., 2013). PAP is classified as a 'phenomenon' whereby a strong muscular contraction (usually resulting from ST using loads >87% 1RM) augments subsequent force-generation capabilities via elevated neural stimulation, enhanced motor-unit recruitment and myosin light-chain phosphorylation (Chiu & Barnes, 2003;Farup & Sørensen, 2010;Gilbert & Lees, 2005;Hrysomallis & Kidgell, 2001). As a result, CT can enhance force potential due to superior motor-unit availability in subsequent muscular contractions (Crewther et al., 2011), making this method of RT potentially useful to boxing where RFD is critical to success (Aagaard et al., 2002;Olsen & Hopkins, 2003;Loturco et al., 2016). ...
Punches in boxing are intricate actions requiring the coordinated and synergistic recruitment of leg, trunk and arm musculature. Maximal punches can have a marked impact on the outcomes of boxing contests. Currently, there is an absence of research appraising the biomechanics and physical performance-related qualities associated with boxing punches, and as such, there are no practical guidelines pertaining to resistance training and its impact upon these important characteristics. In this respect, coaches and boxers are reliant consequently upon non-scientific approaches to training and contest preparation. Thus, the purpose of this thesis was to quantify the biomechanics and physical performance-related qualities associated with maximal punching techniques common to amateur boxing, and investigate the extent to which resistance training enhances such features.
Study 1 quantified the three-dimensional kinetics and kinematics of maximal punches common to boxing competition to identify the differences between punch types (straights, hooks, and uppercuts), whilst Study 2 investigated the movement variability of these measures across punch types. These studies revealed significant differences for the majority of kinetic and kinematic variables between punch types. High within-subject, between-subject, and biological variability were recorded for the same variables across punch types, independent of the amount of boxing experience. These findings confirm that kinetic and kinematic characteristics vary from punch to punch, with boxers appearing to manipulate kinematic variables in order to achieve a consistent intensity and end-product. Study 3 quantified the relationships between physical performance-related traits and kinetic and kinematic qualities of maximal punches, and revealed moderate-to-large associations with muscular strength and power. From this, Study 4 appraised the extent to which strength and contrast resistance training enhanced maximal punch biomechanics and physical performance-related qualities. The findings highlighted that contrast training was superior among male amateur boxers over a six-week intervention, though strength training alone also brought about improvements.
This current research has advanced our understanding of maximal punching and the influence of resistance training on a variety of its determinants. Nonetheless, future research is required to identify if the same findings can be generalised to higher standards of boxing and whether alternative strength and conditioning strategies are equally, or more effective.
... Fitness-Fatigue model suffers from its univariate configuration in modelling athletic performances. While it is known that athletic performance is multifactorial (Avalos, Hellard, and Chatard 2003;Bazyler, Abbott, Bellon, et al. 2015;Mujika, Busso, Lacoste, et al. 1996;Stone, Stone, and Sands 2007), variations in performances may not be fully explained by the dynamics of training loads only, resulting in poor predictive capability (Chiu and Barnes 2003;Pfeiffer 2008;Taha and Thomas 2003). Recently, Piatrikova, Willsmer, Altini, et al. 2021 provided a multivariate alternative to the original FFM. ...
The first models of training effects on athletic performance emerged with the work of Banister and Calvert through the so-called Fitness-Fatigue model (FFM). One major drawback of FFMs is that the features stem from a single source of data. That is not in line with the existing consensus about a multifactorial aspect of athletic performance. Hence, multivariate modelling approaches from statistics and machine-learning (ML) emerged.
A research issue arises from the quantification of training Loads (TL) in resistance training (RT) which lack of physiological evidence. In the first study, we provided a new method of TL quantification in RT based on physiological observations. To achieve that, we initially modelled the torque-velocity profiles of fifteen participants during an isokinetic leg extension task and assessed a set of physiological responses to various resistance exercises intensities. Each session was volume-equated according to the formulation of volume load (i.e. the product of the number of repetitions and the relative intensity).
Higher led to greater muscular fatigue described by neuromuscular impairments. Conversely, systemic and local pulmonary responses (measured through oxygen uptake) and metabolic changes (according to blood lactate concentrations) were more significant at low intensities, suggesting different contributions of metabolic pathways.
From these results, we provided a new index of TL based on the neuromuscu- lar impairments observed at exercise. We showed that to exponentially weight TL by the average rate decay of force development rate yielded better correla- tions with any of the significant physiological responses to exercise. In addition, information compressed within a principal component could be a valuable TL index.
In the second study, we provided a robust modelling methodology that relies on model generalisation. Using data from elite speed skaters, we compared a dose-response model to regularisation methods and machine-learning models.
Regularisation procedures provided the greatest performances in both generalisa- tion and accuracy. Also, we highlighted the pertinence of computing one model over the group of athletes instead of a model per athlete in a context of a small sample size.
Finally, ML approaches could be a way of improving FFMs through ensemble learning methods.
In the third study, we modelled acceleration-velocity directly from global posi- tioning system (GPS) measurements and attempted to predict the coefficients of the relationship between acceleration and velocity.
First, a baseline model was defined by time-series forecasting using game data only. Then, we proceeded to multivariate modelling using commercial features. A regularised linear regression and a long short term memory neural network were compared. Finally, we extracted features directly from raw GPS data and compared these features to the commercial ones for prediction purposes.
The results showed only slight differences between model accuracy, and no models significantly outperformed the baseline in the prediction task. Given the multi- factorial nature of athletic performance, using only GPS data for predicting such athletic performance criterion provided an acceptable accuracy. Using time-domain and frequency-domain features extracted from raw data led to similar performances compared to the commercial ones, despite being evidence-based. It suggests that raw data should be considered for future athletic performance and injury occurrence analysis.
Lastly, we developed an athlete management system for long-distance runners. This application provided an athlete monitoring module and a predictive module based on a physiological model of running performance.
A second development was realised under the SAP analytics cloud solution. Team management and automated dashboards were provided herein, in close collaboration with a professional Rugby team.
... However, the top down approach proposed by Gorban et al. [11,12] may allow for new incorporations and evolutions of the concept of AE within exercise science. For example, the fitness fatigue model of adaption suggests that individuals accumulate both fitness and fatigue over time [13]. Although not completely understood, exercise science provides several mechanisms which may explain fatigue and others that may explain increases in "fitness". ...
... Por un lado, los métodos tradicionales recurrieron a grandes bloques de preparación que culminaban con un periodo breve de competición (Matveyev, 1977), fundamentadas en el síndrome general de adaptación (Selye) y en las leyes biológicas. Por otro lado, los modelos contemporáneos obligados por el actual formato de competición y la integración de nuevos formatos de entrenamientos con la incorporación del balón en las tareas físicas modificaron la orientación y distribución de las cargas de entrenamiento (Andersen, 2006;Arjol, 2012;Chiu, & Barnes, 2003;Dantas, E., García-Manso, J. M. Salum de Godoy, E., Sposito-Araujo, C. A. & Gomes, 2010;Kiely, 2012) con el objetivo de asegurar un estado de forma idóneo y numerosos picos de rendimiento a lo largo de la competición (Navarro, 2000). ...
El objetivo de este estudio fue conocer en qué medida influyen los partidos de fútbol y su distribución durante una pretemporada en la planificación del entrenamiento. Para ello, 21 jugadores semi-profesionales masculinos (20.9 ± 1.7 años; 1.8 ± 0.05 m.; 73.1 ± 5.3 kg.; 8 ± 0.9 % graso; VO2máx. 56.06 ± 2.68 ml./kg./min.) participaron en este estudio. Las variables analizadas durante los partidos fueron: la distancia total recorrida; la velocidad media y máxima; la intensidad de juego clasificada según su velocidad en varias zonas: carrera (14-19 km./h.), carrera intensa (19-24 km./h.) y sprint (>24 km./h.); así como la carrera a alta intensidad (sumatorio de la carrera, carrera intensa y sprint). Tras analizar la carga externa de los 6 microciclos que componían la pretemporada se ha podido observar que la distribución y el número de partidos de fútbol durante una pretemporada han podido influir en la planificación de las sesiones de entrenamiento. Por tanto, se debería prestar especial atención al diseño del volumen e intensidad de la primera y última semana de entrenamiento, evitando, por un lado, cualquier situación lesiva que pudiera apartar al jugador de las sesiones de entrenamiento y, por otro lado, evitar la fatiga acumulada durante el periodo preparatorio ya que podría provocar un descenso del rendimiento al comienzo de la temporada debido a la selección de tareas, al número de partidos disputados y al escaso tiempo de recuperación durante el periodo preparatorio.Palabras clave. Pretemporada; fútbol; planificación; fatiga; G.P.S.Abstract. The aim this study was to determine the extent of the influence of football matches and their distribution during a pre-season training programme planning. For this purpose, 21 male semi-professional players (20.9 ± 1.7 years; 1.8 ± 0.05 m.; 73.1 ± 5.3 kg.; 8 ± 0.9% fat; VO2max. 56.06 ± 2.68 ml./kg./min.) participated in this study. The variables analysed during the matches were: total distance covered; average and maximum speed; game intensity classified in several speeds: running (14-19 km./h.), high intensity running (19-24 km./h.) and sprinting (> 24 km./h.); and distance at high intensity (sum of running, high intensity running and sprinting). After analysing the external load of the 6 microcycles and 9 matches composing the pre-season, we have observed that the distribution and the number of football matches during a pre-season have influenced the training sessions planning. Therefore, special attention should be paid to the design of the volume and intensity of the first and last week of training, avoiding on the one hand, any harmful situation that could take the player apart from the training sessions and on the other hand, avoid the accumulated fatigue during the preparatory period, as it may cause a drop in performance at the beginning of the season due to the selection of tasks, the number of matches and the limited recovery time during the preparatory period.Keywords. Pre-season; football; planning; fatigue; G.P.S.
... Provided enough time is given for the negative effect of fatigue to subside between exercise bouts, the cumulative fitness effects of long term training will lead to improved physical capacity (Bompa & Haff, 1999). It has also been proposed that there are fitness and fatigue effects on more than one system of the body (Chiu & Barnes, 2003). Specific stimuli will have different fatigue responses (e.g. ...
... Fitness-fatigue models (FFMs) underpin concepts guiding the theory and practice of physical training in exercise science 1 . In general, FFMs posit that a single bout of training creates two antagonistic after-effects including a positive long-lasting and low magnitude fitness effect, and a negative short-lasting and high-magnitude fatigue effect 2 . ...
The standard fitness-fatigue model (FFM) was developed more than 40 years ago and remains a prominent conceptual model within exercise science. Translation from a conceptual form into a mathematical structure reveals a collection of models (FFMs) with common properties linking training inputs to performance outcomes. The greatest potential use of FFMs is to predict future performance of athletes with sufficient accuracy to assist with training program design and planning key tapering periods. However, despite a long history and consistent study, there has been limited uptake in practice. This is most likely due to a lack of accessible resources explaining key concepts and processes required to fit models, and uncertainty regarding overall predictive validity. Part I of this review series provides a comprehensive overview of FFMs and discusses three key aspects of fitting models including: 1) training load quantification; 2) criterion performance selection; and 3) parameter estimation. As the majority of athletes engage in sports where performance is complex and determined by a range of physical, psychological and technical factors, it is argued that FFMs may be best placed to quantify components of fitness (e.g., strength, power) targeted by an athlete’s training, rather than competitive outcomes. Additionally, contemporary approaches to training monitoring (e.g., measurement of barbell velocity and repetitions in reserve) are recommended as tools to generate high frequency “performance” measures to better fit FFMs. Essential further developments require collaboration between researchers and practitioners with larger data sets to establish conditions where accurate predictions to future training could be obtained. A set of code-based resources in the R programming language are included with the review series to assist in fitting and evaluating models, and to enhance understanding of concepts described.
... Therefore, the previous descriptions of autoregulation can be seen as adjustments that are made on the basis of measuring performance, where deviations may be disproportionately affected by one or more of the constituents. For example, with an untrained individual engaging in an intense strength training programme, it is probable that rapid increases in performance will occur [57]. In such a case, adjustments made to training through measurement of performance will be influenced primarily by fitness. ...
Autoregulation is a process that is used to manipulate training based primarily on the measurement of an individual's performance or their perceived capability to perform. Despite being established as a training framework since the 1940s, there has been limited systematic research investigating its broad utility. Instead, researchers have focused on disparate practices that can be considered specific examples of the broader autoregulation training framework. A primary limitation of previous research includes inconsistent use of key terminology (e.g., adaptation, readiness, fatigue, and response) and associated ambiguity of how to implement different autoregulation strategies. Crucially, this ambiguity in terminology and failure to provide a holistic overview of autoregulation limits the synthesis of existing research findings and their dissemination to practitioners working in both performance and health contexts. Therefore, the purpose of the current review was threefold: first, we provide a broad overview of various autoregulation strategies and their development in both research and practice whilst highlighting the inconsistencies in definitions and terminology that currently exist. Second, we present an overarching conceptual framework that can be used to generate operational definitions and contextualise autoregulation within broader training theory. Finally, we show how previous definitions of autoregulation fit within the proposed framework and provide specific examples of how common practices may be viewed, highlighting their individual subtleties.
... Prior research has suggested non-caffeine consumers display heightened physiological and psychological responses to caffeine 26 . Furthermore, the non-caffeine consumers in this study reported high physical activity participation (Table 1), suggesting tolerance of a single-bout of aerobic exercise with little fatigue and discomfort 27 . Previous studies have identified that exercise tolerance is implicated in exercise-cognition investigations as individuals who do not regularly exercise are more likely to experience fatigue, which has been associated with impaired cognitive performance 28 . ...
Studies show that a single bout of exercise confers cognitive benefits. However, many individuals use psychoactive substances such as caffeine to enhance cognitive performance. The effects of acute exercise in comparison to caffeine on cognition remain unknown. Furthermore, caffeine use is associated with withdrawal symptoms upon cessation. Whether acute exercise can reduce withdrawal symptoms also remains unknown. The objectives of this study were to compare the effects of acute moderate intensity aerobic exercise to caffeine on working memory (WM) and caffeine withdrawal symptoms (CWS). In Phase I, non-caffeine (n = 29) and caffeine consumers (n = 30) completed a WM assessment, followed by acute exercise and caffeine. In Phase II, caffeine consumers (n = 25) from Phase I underwent the WM assessment and reported CWS following a 12-hour deprivation period. Acute moderate intensity aerobic exercise and caffeine (1.2 mg/kg) significantly improved WM accuracy and reduced CWS comparably. WM performance was not reduced following caffeine deprivation.
... The fitness-fatigue model has been used for decades primarily as a conceptual framework that describes the training process. 1 In its most basic form, the model posits that a single bout of training creates two antagonistic after-effects including a positive longlasting and low-magnitude fitness effect, and a negative short-lasting and high-magnitude fatigue effect. These antagonist components then combine to describe an athlete's performance and state of preparedness. ...
This study investigated the effects of measurement error and testing frequency on prediction accuracy of the standard fitness-fatigue model. A simulation-based approach was used to systematically assess measurement error and frequency inputs commonly used when monitoring the training of athletes. Two hypothetical athletes (intermediate and advanced) were developed and realistic training loads and daily ‘true’ power values were generated using the fitness-fatigue model across 16 weeks. Simulations were then completed by adding Gaussian measurement errors to true values with mean 0 and set standard deviations to recreate more and less reliable measurement practices used in real-world settings. Errors were added to the model training phase (weeks 1–8) and sampling of data was used to recreate different testing frequencies (every day to once per week) when obtaining parameter estimates. In total, 210 sets of simulations (N = 10⁴ iterations) were completed using an iterative hill-climbing optimisation technique. Parameter estimates were then combined with training loads in the model testing phase (weeks 9–16) to quantify prediction errors. Regression analyses identified positive associations between prediction errors and the linear combination of measurement error and testing frequency ( R adj 2 =0.87–0.94). Significant model improvements (P < 0.001) were obtained across all scenarios by including an interaction term demonstrating greater deleterious effects of measurement error at low testing frequencies.The findings of this simulation study represent a lower-bound case and indicate that in real-world settings, where a fitness-fatigue model is used to predict training response, measurement practices that generate coefficients of variation greater than ≈ 4% will not provide satisfactory results.
... Thus, it would appear a typical training week has minimal detrimental effects on the training status of individual players. This may be due to the players being Due to the physically demanding nature of high-intensity training drills in which the aim is to disrupt homeostasis to promote physiological adaptation, it may be possible players experience a period of residual fatigue (Chiu & Barnes, 2003;Twomey et al., 2017). It is therefore of interest to establish the effect of high-intensity training drills on neuromuscular function and investigate the associated time-course of recovery. ...
The physical demands of soccer match play have significantly increased in recent years. As such, training methods must evolve to ensure players are able to cope with these demands over the course of a season. Speed endurance training is recommended to improve physical performance in elite soccer players, however scientific investigations into different protocols and modalities are sparse.
The aim of Study 1 was to determine the exposure to speed endurance training over a season relative to all other conditioning drills. Secondary data was quantified over a 42-week season in an elite youth soccer team using five different conditioning drill categorisations. Speed endurance maintenance and extensive endurance where the most prominent conditioning drills whilst speed endurance production was the least frequent. Nonetheless, the relative distribution of running drills and small-sided games were almost equal for both speed endurance protocols. An investigation into different speed endurance modes and protocols in Study 2 revealed running drills elicit greater heart rate, blood lactate concentration and subjective ratings of perceived exertion than respective small- sided games. Players covered less total distance and high-intensity running distance in the small-sided games, but greater high-intensity acceleration/deceleration distance than in the respective running drills. Additionally, the speed endurance production drills produced greater blood lactate concentrations and high speed running demands than the respective maintenance protocols. These findings suggest speed endurance small-sided games could be used to train the anaerobic energy system, however a greater physiological response may be possible with soccer drills that expose players to greater high speed running demands.
The aim of study 3 was to quantify movement patterns, technical skills and tactical actions associated with high speed running efforts during elite match play to provide information for position-specific speed endurance drills. Twenty individual English Premier League players high-intensity running profiles were observed multiple times using a computerised tracking system. Data was coded using a novel ‘High-intensity Movement Programme’ and revealed position-specific trends in and out of possession. This investigation was the first study to contextualise why playing positions perform high- intensity running efforts rather than simply reporting distances covered. In possession, wide midfielders executed more tricks post effort than centre backs and central midfielders whilst fullbacks and wide midfielders performed more crosses post effort than other positions. Out of possession, forwards completed more efforts closing down the opposition but less efforts tracking opposition runners than other positions. Distinct movement patterns were also evident out of possession with forwards performing more arc runs before efforts compared to centre backs, fullbacks and wide midfielders, however centre backs completed more 0-90° turns compared to fullbacks, central and wide midfielders.
The data from Study 3 was used to design five individual position-specific speed endurance drills with the aim of exposing players to high speed running and the associated technical and tactical actions performed during a match. An investigation into the position- specific speed endurance drills in Study 4 revealed players covered greater distances across all speed thresholds attaining greater peak and average running speeds during the speed endurance production protocol compared to the maintenance drill. Mean and peak heart rate responses were greater in the maintenance protocol whilst blood lactate concentrations were higher following the production protocol. Minimal differences in neuromuscular function and ratings of perceived recovery were evident following either protocol up to 24 h post drill. The findings suggest position-specific speed endurance production drills should be prescribed to achieve a greater anaerobic stimulus and expose players to high running speeds whilst the maintenance protocol should be administered when a greater cardiovascular load is desirable with a concomitant reduction in high speed running.
This research programme provides novel information comparing the physiological response and physical demands of various speed endurance drills in soccer. These studies were the first to report seasonal speed endurance practice and detail generic and position-specific speed endurance soccer drills based on contextualised match data. It is hoped the data from this research project can help applied staff understand the most appropriate speed endurance practices for elite youth players.
Pairwise comparison of heavy dynamic strength and fast dynamic strength interventions on sprint performance: a systematic review and meta-analysis. J Strength Cond Res 38(8): 1509–1520, 2024—Previous studies have shown that both heavy dynamic strength (HDS) and fast dynamic strength (FDS) training can be used to improve sprint performance; however, a review and meta-analysis investigating pairwise studies that compare these two training interventions have not been performed. The aims of the study were to systematically review and analyze HDS and FDS training methodologies and evaluate their effect size difference, in pairwise comparison studies to determine and compare their effects on sprint performance. Databases were systematically searched using Boolean phrasing to identify eligible articles, and meta-analyses were performed on the extracted data. Seven studies met the inclusion criteria, which resulted in data from 138 subjects across 24 separate sprint assessments. Overall, there was a small effect in favor of FDS (standardized mean difference = 0.27, 95% confidence intervals [−0.07; 0.60], 95% prediction intervals [−1.01; 1.55]), but this was deemed not significant because of the wide-ranging prediction intervals. There is no distinguishable difference between HDS and FDS training on sprint performance. The wide-ranging prediction intervals suggest the variability is too great to determine whether one training type is more effective than the other. Practitioners should consider the individual needs of their athletes when deciding which training type to use for long-term sprint development.
The use of exercise interventions to maximize athletes' performance is a common practice in competitions. This systematic review aimed to compile research that explored the effectiveness of priming strategies to maximize physical performance in track and field. The literature search was conducted from PubMed and Scopus. One hundred eighty-two studies were assessed against the inclusion criteria: (a) minimum 1-year participation/competition experience; (b) randomized controlled trials with pre-post intervention outcomes; and (c) studies involving exercise interventions applied ≤6 hours before outcome measures were collected. Fifteen studies satisfied the criteria and were categorized according to the exercise interventions used (i.e., resistance training, plyometric/ballistic training, resisted sprints, and modified warm-ups). Heavy-loaded resistance training (i.e., >85% 1 repetition maximum) and resisted sprints increased subsequent sprint performance. Plyometrics/ballistic training also positively impacted subsequent jumping (i.e., long jump) and throwing performance (i.e., shot put). Modified warm-ups (i.e., high-intensity sprints and heavier throwing implements) also improved subsequent running and throwing performance. Overall, exercise interventions performed at high intensity and low volume augment subsequent physical performance as close to 4 minutes before the event. However, a sufficient recovery interval must be considered for a positive performance response.
Fatigue is a phenomenon associated with decreases in both physical and cognitive performances and increases in injury occurrence. Competitive athletes are required to complete demanding training programmes with high workloads to elicit the physiological and musculoskeletal adaptations plus skill acquisition necessary for performance. High workloads, especially sudden rapid increases in training loads, are associated with the occurrence of fatigue. At present, there is limited evidence elucidating the underlying mechanisms associating the fatigue generated by higher workloads and with an increase in injury risk. The multidimensional nature and manifestation of fatigue have led to differing definitions and dichotomies of the term. Consequently, a plethora of physiological, biochemical, psychological and performance markers have been proposed to measure fatigue and recovery. Those include self-reported scales, countermovement jump performance, heart rate variability, and saliva and serum biomarker analyses. The purpose of this review is to provide an overview of the fatigue and recovery plus methods of assessments.
This study aimed to analyze acute changes in the muscle mechanical properties of the triceps brachii long head after bench press exercise performed at different external loads and with different intensities of effort along with power performance. Ten resistance-trained males (age: 27.7 ± 3.7 yr, body mass: 90.1 ± 17.1 kg, height: 184 ± 4 cm; experience in resistance training: 5.8 ± 2.6 yr, relative one-repetition maximum (1RM) in the bench press: 1.23 ± 0.22 kg/body mass) performed two different testing conditions in a randomized order. During the experimental session, participants performed four successive sets of two repetitions of the bench press exercise at: 50, 70, and 90% 1RM, respectively, followed by a set at 70% 1RM performed until failure, with a 4 min rest interval between each set. Immediately before and after each set, muscle mechanical properties of the dominant limb triceps brachii long head were assessed via a Myoton device. To determine fatigue, peak and average barbell velocity were measured at 70% 1RM and at 70% 1RM until failure (only first and second repetition). In the control condition, only muscle mechanical properties at the same time points after the warm-up were assessed. The intraclass correlation coefficients indicated “poor” to “excellent” reliability for decrement, relaxation time, and creep. Therefore, these variables were excluded from further analysis. Three-way ANOVAs (2 groups × 2 times × 4 loads) indicated a statistically significant group × time interaction for muscle tone (p = 0.008). Post hoc tests revealed a statistically significant increase in muscle tone after 70% 1RM (p = 0.034; ES = 0.32) and 90% 1RM (p = 0.011; ES = 0.56). No significant changes were found for stiffness. The t-tests indicated a significant decrease in peak (p = 0.001; ES = 1.02) and average barbell velocity (p = 0.008; ES = 0.8) during the first two repetitions of a set at 70% 1RM until failure in comparison to the set at 70% 1RM. The results indicate that low-volume, high-load resistance exercise immediately increases muscle tone but not stiffness. Despite no significant changes in the mechanical properties of the muscle being registered simultaneously with a decrease in barbell velocity, there was a trend of increased muscle tone. Therefore, further studies with larger samples are required to verify whether muscle tone could be a sensitive marker to detect acute muscle fatigue.
Post-activation potentiation (PAP) is a phenomenon which can improve force performance executed after a previous conditioning activity. PAP is usually evoked through heavy resistance, but many new methods are being suggested that acutely improve performance in post-activation potentiation protocols. The purpose of this study was to examine the effect of simultaneous application of Smith machine back squats (BS) with electromyostimulation (EMS) on sprint performance. Sixteen male (age = 22.9 ± 2.3 years, body mass = 79.9 ± 13.8 kg, BS one-repetition maximum (1 RM) = 120.5 ± 17.3) amateur football and rugby players volunteered for this study. Participants randomly performed PAP protocols (CON = no load, BS = 3 × 85% of 1 RM BS, EMS = 3 × weightless squat with electric current and BS + EMS = 3 × 85% 1 RM BS with electric current) on four different days with at least 48 h intervals. Participants rested passively for 7 min after preloads and performed the 30 m sprint test. Sprint times for 10 and 30 m were recorded for each condition. As a result, no significant difference was found in the 10 m (p = 0.13) and 30 m (p = 0.10) sprint performance between the preload protocols. The effect size was found to be trivial (ηp2: 0.13 for 10 m; ηp2: 0.11 for 30 m). In individual results, the 10 m sprint performance of five participants and 30 m sprint performance of two participants decreased in BS, EMS, or BS + EMS conditions compared with CON. No PAP effect in other participants was observed. In conclusion, preloads did not affect 10 m and 30 m sprint performance of football and rugby players. It can be said that the applied PAP protocols or physical exertion alone may cause fatigue in some individuals.
As sports technology has continued to develop, monitoring athlete workloads, performance , and recovery has demonstrated boundless benefits for athlete and team success. Specifically, technologies such as global positioning systems (GPS) and heart rate (HR) monitors have granted the opportunity to delve deeper into performance contributors, and how variations may exist based upon context. A team of NCAA Division I women's soccer athletes were monitored during games throughout one competitive season. Individual athlete, positional groups, and team external and internal workloads were explored for differences based upon game location, opponent ranking, game result, and the final score differential. Game location and opponent ranking were found to have no effect on team-wide absolute or relative external workloads, whereas game result and score differential did. Internal workloads across the team tended to only vary by game half, independent of game context; however, the HR of defenders was determined to be higher during losses as compared to wins (p = 0.0256). Notably, the games that resulted in losses also represented the games with the fewest number of substitutions. These findings suggest high value in monitoring performance and workloads that are characteristic of varying, often multifaceted, contexts. It is hoped that this information can lead to more informed approaches to vital game-time and coaching decisions.
In 1987, we analyzed the changes in correlation graphs between various features of the organism during stress and adaptation. After 33 years of research of many authors, discoveries and rediscoveries, we can say with complete confidence: It is useful to analyze correlation graphs. In addition, we should add that the concept of adaptability (‘adaptation energy’) introduced by Selye is useful, especially if it is supplemented by ‘adaptation entropy’ and free energy, as well as an analysis of limiting factors. Our review of these topics, “Dynamic and Thermodynamic Adaptation Models”, attracted many comments from leading experts, with new ideas and new problems, from the dynamics of aging and the training of athletes to single-cell omics. Methodological backgrounds, like free energy analysis, were also discussed in depth. In this article, we provide an analytical overview of twelve commenting papers.
Everett, KLA, Chapman, DW, Mitchell, JA, and Ball, N. Changes in loaded countermovement jumps during precompetition and competition training mesocycles in elite rowers. J Strength Cond Res 36(9): 2622-2627, 2022-To assess changes in velocity, displacement, and power as an indicator of neuromuscular fatigue (NMF) within and between precompetition and competition mesocycles in elite male rowers using loaded countermovement jumps (CMJs). Twenty highly trained rowers completed regular training (on-water rowing, rowing ergometer, and resistance training sessions) in 2 consecutive mesocycles. Athletes completed a single set of 6 loaded (20 kg) CMJs in the first and final week of each mesocycle. Countermovement jumps were assessed for jump height (JH), eccentric displacement, mean velocity (MV), eccentric MV (EMV), and mean power. Changes between time points were reported as Cohen's d effect sizes (95% confidence interval [CI]). The magnitude of the differences was also considered based on their relative strength levels using a linear mixed model. Within the precompetition mesocycle, trivial-to-small reductions for all variables (0.5-4.1%) were observed. During the competition mesocycle, trivial-to-small increases were shown for EMV (1.4%) and eccentric displacement (2.0%) with no change in JH and small reductions in MV (0.5%) and mean power (2.8%). No differences between the precompetition and competition mesocycles were shown. Only mean power showed a significant reduction in weaker athletes (3.2%) compared with stronger athletes (2.3%). Training completed during a precompetition and competitive mesocycle did not result in significant decreases in athlete's loaded CMJ performance, indicating that NMF was minimized. Alternatively, use of a loaded CMJ may not be sensitive enough to observe NMF in elite rowers during the mesocycle immediately leading into and during a competition mesocycle.
Background:
Athlete self-report measures (ASRM) are methods of athlete monitoring, which have gained considerable popularity in recent years. The Multicomponent Training Distress Scale (MTDS), consisting of 22 items, is a promising self-report measure to assess training distress among athletes. The present study aimed to investigate the factorial validity of the Norwegian version of MTDS (MTDS-N) among student-athletes (n = 632) attending the optional program subject "Top-Level Sports" in upper secondary schools in Norway.
Methods:
A confirmatory factor analysis (CFA) was conducted to assess the six-factor model proposed by Main and Grove (2009). McDonald's omega (ω) along with confidence intervals (CIs) were used to estimate scale reliability. After examining the fit of the CFA model in the total sample, covariates were included to investigate group differences in latent variables of MTDS-N, resulting in the multiple indicators multiple causes (MIMIC) model. Further, direct paths between the covariates and the factor indicators were included in an extended MIMIC model to investigate whether responses to items differed between groups, resulting in differential item functioning (DIF).
Results:
When modification indices (MIs) were taken into consideration, the alternative CFA model revealed that MTDS-N is an acceptable psychometric tool with a good fit index. The factors in MTDS-N all constituted high scale reliability with McDonald's ω ranging from 0.725-0.862. The results indicated statistically significant group differences in factor scores for gender, type of sport, hours of training per week, school program, and school level. Further, results showed that DIF occurred in 13 of the MTDS-N items. The student-athletes' reports of training distress were moderate.
Conclusion:
The MTDS-N may be suitable for use in a Norwegian population to assess student-athletes' training distress in a reliable manner. The indications of group effects suggest that caution should be used if one is interested in making group comparisons when the MTDS-N is used among student-athletes in Norway until further research is conducted.
PQ] © by IAAF 11:4:67-81,1996 % ^ /n numerous sports and sport events performance is, to a great extent, determined by the level of speed-strength. An optimal preparation (worm-up) is necessary to achieve the highest possible realization of speed-strength in training and competition. Some top international athletes ore said to have produced the highest speed and speed-strength performances immediately after having performed a few Maximal Voluntary Contractions (MVCs). However, os yet no target-oriented and systematic studies of MVCs. as an element of warm-up programmes, have been conducted. Therefore the focus of the following study is on the following questions: (1) To what extent can the short-term potentia-tion of speed-strength induced by MVCs be considered us a general effect? (2) Can effects of post-tetanic potentiation be triggered in human beings by MVCs? (3) To what extent Is there a connection between possible short-term increases in speed-strength and neuronal effects of post-tetanic potentiation? The results of two complex training experiments show that MVCs carried out during the warm-up can really lead to a considerable increase In speed-strength performances of the lower extremities in alt athletics sprint and jumping events and of the upper extremities in the shot put and the throws, m ^ Dr Arne Gütlich was. from 1992 to 1996.
The concentrations of serum testosterone, sex-hormone-binding-globulin (SHBG) and luteinizing hormone (LH) were examined throughout 1-year of training in six elite weightlifters. A systems model, providing an estimation of fatigue and fitness, was applied to records of training volume and performance levels in clean and jerk. The analysis focused on a 6-week training period during which blood samples were taken at 2-week intervals. A 4-week period of intensive training (period I) could be distinguished from the following 2-week period of reduced training (period II). During period I, decreases in serum testosterone (P less than 0.05) and increases in serum LH concentrations (P less than 0.01) were observed; a significant correlation (r = 0.90, P less than 0.05) was also observed between the changes in serum LH concentration and in estimated fitness. The magnitude of LH response was not related to the change in serum androgens. On the other hand, the change in testosterone:SHBG ratio during period II was significantly correlated (r = 0.97, P less than 0.01) to the LH variations during period I. These finding suggested that the LH response indicated that the decrease in testosterone concentration was not primarily due to a dysfunction of the hypothalamic-pituitary system control, and that the fatigue/fitness status of an athlete could have influenced the LH response to the decreased testosterone concentration. The negative effect of training on hormonal balance could have been amplified by its influence on the hypothalamic-pituitary axis. A decrease in physiological stress would thus have been necessary for the completion of the effect of LH release on androgenic activity.
To examine endogenous anabolic hormonal responses to two different types of heavy resistance exercise protocols (HREPs), eight male and eight female subjects performed two randomly assigned protocols (i.e. P-1 and P-2) on separate days. Each protocol consisted of eight identically ordered exercises carefully designed to control for load, rest period length, and total work (J) effects. P-1 utilized a 5 RM load, 3-min rest periods and had lower total work than P-2. P-2 utilized a 10 RM load, 1-min rest periods and had a higher total work than P-1. Whole blood lactate and serum glucose, human growth hormone (hGH), testosterone (T), and somatomedin-C [SM-C] (i.e. insulin-like growth factor 1, IGF-1) were determined pre-exercise, mid-exercise (i.e. after 4 of the 8 exercises), and at 0, 5, 15, 30, and 60 min post-exercise. Males demonstrated significant (p less than 0.05) increases above rest in serum T values, and all serum concentrations were greater than corresponding female values. Growth hormone increases in both males and females following the P-2 HREP were significantly greater at all time points than corresponding P-1 values. Females exhibited significantly higher pre-exercise hGH levels compared to males. The P-1 exercise protocol did not result in any hGH increases in females. SM-C demonstrated random significant increases above rest in both males and females in response to both HREPs.(ABSTRACT TRUNCATED AT 250 WORDS)
To examine endogenous anabolic hormone and growth factor responses to various heavy resistance exercise protocols (HREPs), nine male subjects performed each of six randomly assigned HREPs, which consisted of identically ordered exercises carefully designed to control for load [5 vs. 10 repetitions maximum (RM)], rest period length (1 vs. 3 min), and total work effects. Serum human growth hormone (hGH), testosterone (T), somatomedin-C (SM-C), glucose, and whole blood lactate (HLa) concentrations were determined preexercise, midexercise (i.e., after 4 of 8 exercises), and at 0, 5, 15, 30, 60, 90, and 120 min postexercise. All HREPs produced significant (P less than 0.05) temporal increases in serum T concentrations, although the magnitude and time point of occurrence above resting values varied across HREPs. No differences were observed for T when integrated areas under the curve (AUCs) were compared. Although not all HREPs produced increases in serum hGH, the highest responses were observed consequent to the H10/1 exercise protocol (high total work, 1 min rest, 10-RM load) for both temporal and time integrated (AUC) responses. The pattern of SM-C increases varied among HREPs and did not consistently follow hGH changes. Whereas temporal changes were observed, no integrated time (AUC) differences between exercise protocols occurred. These data indicate that the release patterns (temporal or time integrated) observed are complex functions of the type of HREPs utilized and the physiological mechanisms involved with determining peripheral circulatory concentrations (e.g., clearance rates, transport, receptor binding). All HREPs may not affect muscle and connective tissue growth in the same manner because of possible differences in hormonal and growth factor release.
Twelve, highly trained male swimmers were studied before, during, and after 10 successive days of increased training in an attempt to determine the physical effects of training over-load. Their average training distance was increased from 4,266 to 8,970 m.d-1, while swimming intensity was maintained at 94% (SE +/- 2%) of their maximal oxygen uptake, resulting in an average caloric cost during training of 2,293 kcal.d-1 (+/- 74). As a result of the intensified training regimen, the swimmers experienced local muscular fatigue and difficulty in completing the training sessions. Nevertheless, their swimming power, sprinting (s.22.86 m-1), endurance (s.365.8 m-1) performance, aerobic capacity, and muscle (m. deltoid) citrate synthase were unchanged as a consequence of the 10-d training regimen. Four of the 12 swimmers were, however, unable to tolerate the heavier training demands, and were forced to swim at significantly slower (P less than 0.05) speeds during the training sessions. These men were found to have significantly reduced muscle glycogen values, which was the result of their abnormally low carbohydrate intake. The findings of this research suggest that some swimmers may experience chronic muscular fatigue as a result of their failure to ingest sufficient carbohydrate to match the energy demands of heavy training.
The purpose of this investigation was to study a high-intensity resistance exercise overtraining protocol resulting in muscular strength decrements. Seventeen weight-trained males were divided into an overtraining group (OT; N = 11; mean +/- SE, age = 22.0 +/- 0.9 yr,) that exercised on a squat machine daily for 2 wk with 100% of 1 repetition maximum (RM) relative intensity, and a control group (CON; N = 6; age = 23.7 +/- 2.4 yr) that exercised 1 d.wk-1 with low intensity (50% 1 RM). Test batteries were conducted at the beginning (test 1), after 1 wk (test 2), and after 2 wk (test 3) of the study. One RM performance significantly decreased from test 1 to test 3 (P < 0.05) for the OT group (mean = -12.2 +/- 3.8 kg), but not the CON group (mean = -1.1 +/- 0.8 kg). Isokinetic and stimulated isometric muscle force significantly decreased for the OT group compared with the CON group by test 3. The primary site of maladaptation appeared to be in the periphery as indicated by changes in stimulated force, circulating CK activity, and exercise-induced lactate responses. This protocol produced a significant decrease in 1 RM performance, thus providing a model for the study of short-term, high-intensity resistance exercise overtraining.
The purpose of this study was to compare two ways of estimating both fatigue and fitness indicators from a systems model of the effects of training on performance. The model was applied to data concerning the training of a hammer thrower. The variations in performance were mathematically related to the successive amounts of training. The model equation was composed of negative (NF) and positive (PF) functions. The NF and PF were associated with the fatigue and fitness estimated in previous studies. Using another method, fatigue and fitness indicators were estimated from a combination of NF and PF. The influence of training on performance was negatively associated with fatigue (NI), and positively to fitness (PI). The changes in performance were well described by the model in the present study (r = 0.96, N = 19, P < 0.001). Significant correlations were observed between PF and PI (r = 0.90, P < 0.001) on the other. The absolute values and the time variations of PI and NI were closer to the change in performance than NF and PF. The NF and PF were accounted for mainly by the accumulation of amounts of training. On the other hand, NI and PI were accounted for rather by the impact of these amounts of training on performance.
An 8-wk progressive resistance training program for the lower extremity was performed twice a week to investigate the time course for skeletal muscle adaptations in men and women. Maximal dynamic strength was tested biweekly. Muscle biopsies were extracted at the beginning and every 2 wk of the study from resistance-trained and from nontrained (control) subjects. The muscle samples were analyzed for fiber type composition, cross-sectional area, and myosin heavy chain content. In addition, fasting blood samples were measured for resting serum levels of testosterone, cortisol, and growth hormone. With the exception of the leg press for women (after 2 wk of training) and leg extension for men (after 6 wk of training), absolute and relative maximal dynamic strength was significantly increased after 4 wk of training for all three exercises (squat, leg press, and leg extension) in both sexes. Resistance training also caused a significant decrease in the percentage of type IIb fibers after 2 wk in women and 4 wk in men, an increase in the resting levels of serum testosterone after 4 wk in men, and a decrease in cortisol after 6 wk in men. No significant changes occurred over time for any of the other measured parameters for either sex. These data suggest that skeletal muscle adaptations that may contribute to strength gains of the lower extremity are similar for men and women during the early phase of resistance training and, with the exception of changes in the fast fiber type composition, that they occur gradually.
Nine eumenorrheic women (age 24.11 +/- 4.28 yr) performed each of six randomly assigned heavy-resistance protocols (HREPs) on separate days during the early follicular phase of the menstrual cycle. The HREPs consisted of two series [series 1 (strength, S) and series 2 (hypertrophy, H)] of three protocols, each using identically ordered exercises controlled for load [5 vs. 10 repetitions maximum (RM)], rest period length (1 vs. 3 min), and total work (J) within each three-protocol series. Blood measures were determined pre-, mid- (after 4 of 8 exercises), and postexercise (0, 5, 15, 30, 60, 90, 120 min and 24 and 48 h). In series 1, a significant (P < 0.05) reduction in growth hormone (GH) was observed at 90 min postexercise for all three protocols. In series 2, the 10-RM protocol with 1-min rest periods (H10/1) produced significant increases above rest in GH concentrations at 0, 5, and 15 min postexercise, and the H10/1 and H5/1 protocols demonstrated significant reductions at 90 and 120 min postexercise. Cortisol demonstrated significant increases in response to the S10/3 protocol at 0 min, to the H10/1 protocol at midexercise and at 0 and 5 min postexercise, and to the H5/1 protocol at 5 and 15 min postexercise. No significant changes were observed in total insulin-like growth factor I, total testosterone, urea, or creatinine for any of the HREPs. Significant elevations in whole blood lactate and ammonia along with significant reductions in blood glucose were observed. Hormonal and metabolic blood variables measured in the early follicular phase of the menstrual cycle varied in response to different HREPs. The most dramatic increases above resting concentrations were observed with the H10/1 protocol, indicating that the more glycolytic HREPs may stimulate greater GH and cortisol increases.
Twitch potentiation and fatigue in skeletal muscle are two conditions in which force production is affected by the stimulation history. Twitch potentiation is the increase in the twitch active force observed after a tetanic contraction or during and following low-frequency stimulation. There is evidence that the mechanism responsible for potentiation is phosphorylation of the regulatory light chains of myosin, a Ca2+-dependent process. Fatigue is the force decrease observed after a period of repeated muscle stimulation. Fatigue has also been associated with a Ca2+-related mechanism: decreased peak Ca2+ concentration in the myoplasm is observed during fatigue. This decrease is probably due to an inhibition of Ca2+ release from the sarcoplasmic reticulum. Although potentiation and fatigue have opposing effects on force production in skeletal muscle, these two presumed mechanisms can coexist. When peak myoplasmic Ca2+ concentration is depressed, but myosin light chains are relatively phosphorylated, the force response can be attenuated, not different, or enhanced, relative to previous values. In circumstances where there is interaction between potentiation and fatigue, care must be taken in interpreting the contractile responses.
Various resistance activities are used today to increase the force-generating capacity of specific skeletal muscles. Many interdependent factors influence the magnitude of improvement, but great muscular tension during training appears necessary to elicit the desired changes in muscle function. If adequate tension is to be manifested in specific muscles, they must not be excessively fatigued. Consequently, sufficient rest should be provided during and between strength-training sessions in order for recovery to occur. In addition, when other components of motor or physical fitness are concurrently being developed, precautions should be taken so that fatigue does not adversely affect strength development. In many cases, this requires the conduction of strength training and other conditioning activities during dedicated times within a session or at different times of the day. Rest may be categorized as occurring during a training session (intratraining-session rest), between training sessions (intertraining session rest) and just before a performance or test (pre-performance rest). In order to enhance muscular tension during strength training, the phosphagen system should serve as the primary catabolic vehicle for the resynthesis of adenosine triphosphate (ATP). Five or fewer repetitions of each lift should be completed per set, and exercises involving some of the same muscle groups should be separated by about three or four minutes, depending on the trainee’s recovery capacity. Specific guidelines currently are unavailable concerning intertraining-session rest due to methodological dilemmas in experiments designed to test them. The primary problems to be resolved are to identify a physiological marker indicating the point of maximal overcompensation consequent to each training session, and whether training volume should be standardized per session or per week. Evidence relating strength to pre-performance rest is meager at best. However, some preliminary work appears to indicate that 96 hours of rest may enhance strength performance as measured against a constant external load, while 48, 72 and 120 hours of rest appear to have no significant effect on moderately trained men. Although these findings are preliminary, they do seem to coincide with the effects of tapering during training for competitive swimmers.
The purpose of this study was to determine if 3 weeks of high relative intensity (percent one repetition maximum [1RM]) free-weight resistance training using the parallel barbell squat results in overtraining and to determine what types of performance would be affected. Six weight-trained males (X̄ ± SD; age = 27.5 ± 5.4 year) trained 2 d·wk-1 for 4 weeks with a normal protocol (Monday, 3 X 10 repetition maximum [RM]; Thursday, 3 X 5 RM), followed by 3 weeks of high-intensity training 3 d·wk-1 (Monday, Wednesday, Friday) using 2 X 1 95% 1RM and 3 X 1 90% 1RM. A time-series study design was utilized, with each subject serving as his own control (pretest [Pre] - test 1 = normal training; tests 1-4 = high-intensity training; test 4 - posttest [Post] = recovery). One repetition maximum increased (p < 0.05) during normal training but did not change during high-intensity or recovery training (Pre = 139.5 ± 29.9 kg; test 1 = 154.6 ± 27.7 kg; test 2 = 160.3 ± 26.9 kg; test 3 = 163.7 ± 27.9 kg; test 4 = 161.0 ± 27.2 kg; Post = 161.7 ± 33.3 kg). Muscular and joint pain and soreness were not evident according to self-report training questionnaires. Also during the high-intensity phase, sprint times for 9.1 m increased (test 1 = 1.75 ± 0.12 seconds; test 4 = 1.86 ± 0.12 seconds) and peak isokinetic squat force at 0.20 m·s-1 decreased (test 1 = 2,473.2 ± 685.6 N; test 4 = 2,193.3 ± 534.5 N). In general, no changes were observed for body composition, flexibility, lower body reaction time, vertical jumps, 36.6-m sprints, lateral agility, isokinetic squat force at 0.82 and 1.43 m·s-1, or isokinetic back extension at 0.17 and 1.05 rad·s-1. Although use of single repetitions at a high relative intensity is often used to increase 1RM, this was not observed in the present study. While 1RM performance did not decrease, other performance measures were adversely affected, suggestive of an excessive use of high relative intensity resistance exercise.
To examine the efficacy of a 3-week, high-intensity, resistance exercise protocol for inducing overtraining, 9 subjects trained their lower body on a squat-simulating resistance exercise machine. Five subjects performed a training (Trn) protocol 5 days a week to elicit an overtraining response. Four subjects performed a control (Con) protocol 2 days a week. Test batteries of sprints, jumps, and strength tests were performed four times during the study at l-week intervals (Tl, T2, T3, T4). One-RM performances increased for the Trn group by T2 and remained augmented through T4. Overtraining did not occur, but other performances were attenuated for the Trn group. Increased sprint times for 9.1 m and 36.6 m were evident by T2 for the Trn group and remained slower through T4. Leg extension torque decreased for the Trn group by T4. Future attempts to induce intensity-dependent overtraining for study should use greater training intensities or different training modalities and should monitor physiological factors that may contribute to this phenomenon.
(C) 1994 National Strength and Conditioning Association
Various resistance activities are used today to increase the force-generating capacity of specific skeletal muscles. Many interdependent factors influence the magnitude of improvement, but great muscular tension during training appears necessary to elicit the desired changes in muscle function. If adequate tension is to be manifested in specific muscles, they must not be excessively fatigued. Consequently, sufficient rest should be provided during and between strength-training sessions in order for recovery to occur. In addition, when other components of motor or physical fitness are concurrently being developed, precautions should be taken so that fatigue does not adversely affect strength development. In many cases, this requires the conduction of strength training and other conditioning activities during dedicated times within a session or at different times of the day.
Rest may be categorized as occurring during a training session (intratraining-session rest), between training sessions (intertraining session rest) and just before a performance or test (pre-performance rest). In order to enhance muscular tension during strength training, the phosphagen system should serve as the primary catabolic vehicle for the resynthesis of adenosine triphosphate (ATP). Five or fewer repetitions of each lift should be completed per set, and exercises involving some of the same muscle groups should be separated by about three or four minutes, depending on the trainee's recovery capacity. Specific guidelines currently are unavailable concerning intertraining-session rest due to methodological dilemmas in experiments designed to test them. The primary problems to be resolved are to identify a physiological marker indicating the point of maximal overcompensation consequent to each training session, and whether training volume should be standardized per session or per week. Evidence relating strength to pre-performance rest is meager at best. However, some preliminary work appears to indicate that 96 hours of rest may enhance strength performance as measured against a constant external load, while 48, 72 and 120 hours of rest appear to have no significant effect on moderately trained men. Although these findings are preliminary, they do seem to coincide with the effects of tapering during training for competitive swimmers.
(C) 1991 National Strength and Conditioning Association
To determine if training status directly impacted the response to postactivation potentiation, athletes in sports requiring explosive strength (ATH; n = 7) were compared to recreationally trained (RT; n = 17) individuals. Over the course of 4 sessions, subjects performed rebound and concentric-only jump squats with 30%, 50%, and 70% 1 RM loads. Jump squats were performed 5 minutes and 18.5 minutes following control or heavy load warm-ups. Heavy load warm-up consisted of 5 sets of 1 repetition at 90% 1 RM back squat. Jump squat performance was assessed with a force platform and position transducer. Heavy load warm-up did not have an effect on the subjects as a single sample. However, when percent potentiation was compared between ATH and RT groups, force and power parameters were significantly greater for ATH (p < 0.05). Postactivation potentiation may be a viable method of acutely enhancing explosive strength performance in athletic but not recreationally trained individuals.
(C) 2003 National Strength and Conditioning Association
The effects of a 1 year training period on 13 elite weight-lifters were investigated by periodical tests of electromyographic, muscle fibre and force production characteristics. A statistically non-significant increase of 3.5% in maximal isometric strength of the leg extensors, from 48411104 to 50101012 N, occured over the year. Individual changes in the high force portions of the force-velocity curve correlated (p<0.05–0.01) with changes in weight-lifting performance. Training months 5–8 were characterized by the lowest average training intensity (77.1+2.0%), and this resulted in a significant (p<0.05) decrease in maximal neural activation (IEMG) of the muscles, while the last four month period, with only a slightly higher average training intensity (79.13.0%), led to a significant (p<0.01) increase in maximum IEMG. Individual increases in training intensity between these two training periods correlated with individual increases both in muscular strength (p<0.05) and in the weight lifted in the clean & jerk (p<0.05). A non-significant increase of 3.9% in total mean muscle fibre area occurred over the year. The present findings demonstrate the limited potential for strength development in elite strength athletes, and suggest that the magnitudes and time courses of neural and hypertrophic adaptations in the neuromuscular system during their training may differ from those reported for previously untrained subjects. The findings additionally indicate the importance of training intensity for modifying training responses in elite strength athletes.
Effects of fatigue produced by a maintained 60% isometric loading on electromyographic and isometric force-time and relaxation-time characteristics of human skeletal muscle were studied in 21 males accustomed to strength training. Fatigue loading resulted in a slight but not significant change in the maximal integrated EMG of a maximal isometric contraction, and a large decrease (20.46.3%, p<0.001) in maximal force. Fatigue loading increased (p<0.05–0.01) neural activation of the muscles during rapidly produced submaximal isometric forces, but had a considerable adverse effect (p<0.001) on the corresponding force-time characteristics. Correlations between the relative changes after fatigue in the IEMG/force ratio at the maximal force level, and in the IEMG/force ratios of the early phases of the force-time curve were not significant, but gradually became significant (p<0.01) at higher force levels. The average IEMG of the muscles in the relaxation phase of contraction remained unaltered by fatigue, while a marked deleterious change in the relaxation-time variables (p<0.001) occurred concomitantly. During the subsequent 3 min rest period considerable (12.17.0%, p<0.001) recovery was noted in the maximal force, with smaller (insignificant or p<0.05–0.01) changes in the force-time and relaxation-time variables, while the average IEMG of force production decreased (p<0.01–0.001). The present findings suggest that fatigue leading to a worsening in force-time, in maximal force and in the relaxation-time parts of a maximal isometric contraction might take place primarily in the contractile processes.
Effects of fatigue produced by a maintained 50% isometric loading on electromyographic (EMG) and mechanical characteristics of voluntary and reflex contractions of human skeletal muscles were studied in 14 males. A continuous isometric loading of the knee extensors caused significant (P < 0.001) increase in integrated EMG (IEMG) and decrease (P < 0.001) in mean power frequency (MPF) of the EMG spectrum. The decrease in MPF was related (P < 0.05) to percentage fast twitch (FT) fibre area of the vastus lateralis muscle. In reflexly induced contractions no changes were observed during fatigue in reflex latency (LAT) but electromechanical delay (EMD) increased significantly (P < 0.01). The decrease in voluntary MPF and increase in reflex EMD were interrelated (P < 0.05). Fatigue loading increased (P < 0.05) the peak-to-peak amplitude of EMG of the reflex contraction but decreased (P < 0.01) the corresponding force amplitude. The increase (P < 0.01) in this reflex EMG/force ratio was related (P < 0.05) to the corresponding increase observed in IEMG/force ratio of the voluntary contraction. The present findings support the differential fatiguing properties of fast twitch and slow twitch muscle fibres. In addition the fatigue effects on reflexly induced contractions show that fatigue took place primarily in the contractile processes and that muscle spindle sensitivity was increased during fatigue loading.
The effects were investigated in ten women of intensive heavy resistance strength training lasting for 3 weeks on electromyographic (EMG) activity, muscle cross-sectional area (CSA) and voluntary force production characteristics of leg extensor muscles. Blood samples for the determinations of serum hormones were taken from five of the subjects. Significant increases occurred in the higher force portions of the isometric force-time curve with an increase of 9.7 (SD 8.4)% (P less than 0.01) in maximal peak force. An increase of 15.8 (SD 20.9)% (P less than 0.05) took place also in the maximal neural activation (integrated EMG) of the trained muscles, while an enlargement of 4.6 (SD 7.4)% (P less than 0.05) occurred in the CSA of the quadriceps femoris muscle. Maximal force per muscle CSA increased significantly (P less than 0.05). No statistically significant changes were observed during the training in the mean concentrations of serum testosterone, free testosterone, cortisol and sex hormone binding globulin (SHBG). The individual concentrations of serum testosterone:SHBG ratio correlated with the individual changes obtained during the training in the muscle CSA (r = 0.99; P less than 0.01). The present findings in women indicated that the increases in maximal strength during short-term but intensive strength training were primarily due to the increased voluntary activation of the trained muscles, while muscle hypertrophy remained limited in magnitude. Large interindividual differences in women in serum testosterone concentrations could indicate corresponding differences in muscle hypertrophy and strength development even during a short-term but intensive strength training period.
This study examined some of the physiological and performance effects of three different tapers in highly trained athletes. After 8 wk of training, nine male middle-distance runners were randomly assigned to one of three different 7-day tapers: a high-intensity low-volume taper (HIT), a low-intensity moderate-volume taper (LIT), or a rest-only taper (ROT). After the first taper, subjects resumed training for 4 wk and performed a second taper and then resumed training for 4 wk and completed the remaining taper, so that each subject underwent all three tapers. Performance was measured before and after each taper by a treadmill run to fatigue at a velocity equivalent each subject's best 1,500-m time. Voluntary isometric strength and evoked contractile properties of the quadriceps were measured before and after each taper, as were muscle glycogen concentration and citrate synthase activity (from needle biopsies) and total blood and red cell volume by 125I and 51Cr tagging. Maximal O2 consumption was unaffected by all three tapers, but running time to fatigue increased significantly after HIT (+22%). It was unaffected by LIT (+6%) and ROT (-3%) procedure. Citrate synthase activity increased significantly with HIT and decreased significantly with ROT. Muscle glycogen concentration increased significantly after ROT and HIT, and strength increased after all three tapers. Total blood volume increased significantly after HIT and decreased after ROT.(ABSTRACT TRUNCATED AT 250 WORDS)
Overtraining may be one frequent cause of stagnation or decrease in performance capacity of athletes. Israel (19) differentiates between addisonoid (parasympathetic) and basedowoid (sympathetic) overtraining, characterized by inhibition or excitation. We tried to induce an overtraining syndrome in 8 experienced middle- and long-distance runners, based on an increase in training volume from an average 85.9 km (week 1) to 115.1 km (week 2) and 143.1 km (week 3) to 174.6 km per week (week 4). The influence of this training on cardiovascular, metabolic and hormonal parameters was examined with special respect to plasma and urinary catecholamines. Laboratory testing including graded treadmill running was performed on the days 0, 14 and 28. Training was held six days each week, with nearly 30 km per day in the fourth week. A stagnation in endurance performance capacity (running velocity at the aerobic-anaerobic transition range) and a decrease in maximum working capacity were observed in 6 and a stagnation in 2 of the 8 sportsmen, indicated by a decrease in total running distance from 4719 + 912 m to 4361 + 788 m during incremental treadmill ergometry. The sportsmen could neither improve nor could they even approximately reach their personal records during the subsequent competitive season. Subjective complaints, classified on a four-point scale, increased from 1.2 (week 1) to 3.2 in week 4. Glucose, lactate, ammonia, glycerol, free fatty acids, albumin, LDL, VLDL cholesterol, hemoglobin level (transient), leukocytes, and heart rate (before and during exercise) decreased significantly. Urea, creatinine, uric acid, GOT, GPT, gamma-GT, serum electrolytes (except phosphate and calcium) remained constant at the measuring times, CPK was elevated.(ABSTRACT TRUNCATED AT 250 WORDS)
Training-induced adaptations in the endocrine system and strength development were investigated in nine male strength athletes during two separate 3-week intensive strength training periods. The overall amount of training in the periods was maintained at the same level. In both cases the training in the first 2 weeks was very intensive: this was followed by a 3rd week when the overall amount of training was greatly decreased. The two training periods differed only in that training period I included one daily session, while during the first 2 weeks of period II the same amount of training was divided between two daily sessions. In general, only slight and statistically insignificant changes occurred during training period I in mean concentrations of serum hormones examined or sex hormone-binding globulin as well as in maximal isometric leg extensor force. However, during training period II after 2 weeks of intensive strength training a significant decrease (P less than 0.05) was observed in serum free testosterone concentration [from 98.4 (SD 24.5) to 83.8 (SD 14.7) pmol.l-1] during the subsequent week of reduced training. No change in the concentration of total testosterone was observed. This training phase was also accompanied by significant increases (P less than 0.05) in serum luteinizing hormone (LH) and cortisol concentrations. After 2 successive days of rest serum free testosterone and LH returned to (P less than 0.05) their basal concentrations. Training period II led also to a significant increase (P less than 0.05) [from 3942 (SD 767) to 4151 (SD 926) N] in maximal force.(ABSTRACT TRUNCATED AT 250 WORDS)
Neuromuscular adaptations during a 2-week "normal" strength training period followed by a 1-week reduced training period were investigated in ten strength athletes. No systematic changes were observed in the maximal voluntary neural activation (averaged integrated EMG) of leg extensor muscles, in the cross-sectional area (CSA) of the QF muscle or in maximal voluntary isometric force production characteristics of the leg extensor muscles in the whole subject sample over the entire strength training period of 3 weeks. However, significant increases were observed both in the maximal neural activation (p less than 0.05) and maximal force (from 4547 +/- 613 to 4923 +/- 901 N; p less than 0.05) of the muscles at the very end of the 1-week reduced training period in group A which consisted of five best strength athletes within the whole subject group. In group B consisting of five other athletes at a lower level no systematic changes were observed during the reduced training period. The present findings suggest that neuromuscular adaptations in strength athletes are very limited in magnitude at least during short term strength training. Maximal strength performance in highly trained strength athletes may be brought to the peak level not necessarily during "normal" strength training but more likely after some period of time with a reduced volume of training. The present observations support the concept of the periodization of training in highly trained strength athletes and indicate the important role of the nervous system in leading to the peak in their maximal strength.
Acute effects of fatigue produced by a maintained 60% isometric loading on force production and relaxation characteristics of the leg extensor muscles were studied in male endurance (n = 9), power (n = 6) and strength athletes (n = 9). The initial non-fatigued isometric force-time curves differed considerably (p less than 0.05-0.001) between the groups so that the times of force production were the shortest and correspondingly the maximal rate of force production the greatest in the power athletes but the longest and the smallest in the endurance athletes. The endurance time of 70.7 +/- 32.9 s at the 60% fatiguing loading was in the endurance athletes longer (p less than 0.01) than in the power (30.6 +/- 7.1 s) and strength groups (31.7 +/- 5.5 s). The present fatiguing loading resulted in all athlete groups in significant (p less than 0.05-0.001) worsening in maximal force, in the times of force production and in the maximal rates of force production and relaxation. However, this worsening in the endurance athletes in maximal force (to 92.9 +/- 7.1%) as well as in the maximal rates of force production (to 79.2 +/- 20.8%) and relaxation (to 73.1 +/- 29.2%) were significantly (p less than 0.05-0.01) smaller than the corresponding decreases in the power athletes (to 64.3 +/- 8.0%, 74.8 +/- 7.4% and to 40.9 +/- 12%, respectively) and in the strength athletes (to 65.7 +/- 7.0%, 56.7 +/- 16.0% and to 34.8 +/- 6.7%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)
A systems model, providing an estimation of fatigue and fitness levels was applied to a 1-year training period of six elite weight-lifters. The model parameters were individually determined by fitting the predicted performance (calculated as the difference between fitness and fatigue) to the actual one. The purpose of this study was to validate the systems model by comparing the estimated levels of fatigue and fitness with biological parameters external to the model calculation. The predicted and the actual performances were significantly correlated in each subject. The calculated fitness and fatigue levels were related to serum testosterone concentration, testosterone: cortisol and testosterone: sex hormone binding globulin ratios. The best results were obtained by the comparison between fitness and testosterone levels, which varied in parallel in each subject. In two subjects this correlation was significant (r = 0.91, P less than 0.05, and r = 0.92, P less than 0.01). The fitness changes calculated in each subject between the 15th and the 51st weeks of training were significantly correlated with the changes in serum testosterone concentration measured in the same period (r = 0.99, P less than 0.001). For the whole group testosterone and fitness variations were also significantly intercorrelated (r = 0.73, P less than 0.001). Correlations, less homogeneous and less significant, were calculated also for other hormones and ratios. These results suggest that (1) the relationships between training and performance can be described by the systems model, (2) the estimated index of fitness has a physiological meaning. The fatigue index remains to be clarified.
Daily changes in neural activation, force-time and relaxation characteristics of the leg extensor muscles were examined in 8 elite strength athletes during a very intense strength training period with two daily sessions for one week. The maximal neural activation (integrated EMG) of the muscles and their maximal isometric extension force remained statistically unaltered during the entire experimental period. Average integrated EMG of the muscles during the rapid relaxation phase of the isometric contraction and the relaxation-time curve remained statistically unaltered as well. However, considerable decreases (p less than 0.05-0.001) occurred both in the neural activation and in the force production in the early phases of the rapid isometric contraction during the course of the one-week period. After one full day of rest only slight and statistically nonsignificant changes took place in the mean values of the neuromuscular performance variables examined. The present findings indicate that the high overall daily volume of heavy resistance strength training stimuli may have a considerable role in leading to temporary worsening specifically in the rapid neural activation and correspondingly in rapid force production of the neuromuscular performance capacity even during a very short training period. In athletic training the volume of these types of training stimuli should therefore be carefully considered and matched with the specific purpose of the training season and with the specific requirements of various athletic activities.
Neuromuscular and hormonal adaptations to prolonged strength training were investigated in nine elite weight lifters. The average increases occurred over the 2-yr follow-up period in the maximal neural activation (integrated electromyogram, IEMG; 4.2%, P = NS), maximal isometric leg-extension force (4.9%, P = NS), averaged concentric power index (4.1%, P = NS), total weight-lifting result (2.8%, P less than 0.05), and total mean fiber area (5.9%, P = NS) of the vastus lateralis muscle, respectively. The training period resulted in increases in the concentrations of serum testosterone from 19.8 +/- 5.3 to 25.1 +/- 5.2 nmol/l (P less than 0.05), luteinizing hormone (LH) from 8.6 +/- 0.8 to 9.1 +/- 0.8 U/l (P less than 0.05), follicle-stimulating hormone (FSH) from 4.2 +/- 2.0 to 5.3 +/- 2.3 U/l (P less than 0.01), and testosterone-to-serum sex hormone-binding globulin (SHBG) ratio (P less than 0.05). The annual mean value of the second follow-up year for the serum testosterone-to-SHBG ratio correlated significantly (r = 0.84, P less than 0.01) with the individual changes during the 2nd yr in the averaged concentric power. The present results suggest that prolonged intensive strength training in elite athletes may influence the pituitary and possibly hypothalamic levels, leading to increased serum levels of testosterone. This may create more optimal conditions to utilize more intensive training leading to increased strength development.
Twenty-four men and 26 women (25 +/- 5 years) participating in 10 weeks (n = 27) and 18 weeks (n = 23) of variable resistance strength training programs were recruited to complete 12 weeks of reduced training. Training consisted of one set of 7-10 bilateral knee extensions performed to volitional failure. Prior to the reduced training phase of the project, the subjects were training either 2 days.week-1 (n = 23) or 3 days.week-1 (n = 18). The subjects who trained 3 days.week-1 reduced training frequency to 2 days.week-1 (n = 9), 1 day.week-1 (n = 7), or 0 days.week-1 (n = 2). The subjects who trained 2 days.week-1 reduced training frequency to 1 day.week-1 (n = 12) or 0 days.week-1 (n = 11). Nine subjects served as controls and did not train. Isometric knee extension strength was assessed at 9, 20, 35, 50, 65, 80, 95, and 110 degrees of knee flexion on two separate occasions prior to and immediately post-training and following reduced training. After training, mean relative increases in peak isometric knee extension strength and dynamic training weight were 21.4% +/- 17.5% (P less than or equal to 0.01) and 49.5% +/- 14.7% (P less than or equal to 0.01), respectively. The subjects who stopped training (0 days.week-1) lost 68% (P less than or equal to 0.01) of the isometric strength gained during training.(ABSTRACT TRUNCATED AT 250 WORDS)
Daily adaptive responses in the neuromuscular and endocrine systems to a 1-week very intensive strength training period with two training sessions per day were investigated in eight elite weight lifters. The morning and the afternoon sessions resulted in acute decreases (P less than 0.05-0.01) in maximal isometric strength and in the maximal neural activation (iEMG) of the leg extensor muscles, but the basic levels remained unaltered during the entire training period. Significant (P less than 0.05-0.01) acute increases in serum total and free testosterone levels were found during the afternoon sessions. During the 1-week training period, serum total and free testosterone concentrations decreased gradually (P less than 0.05-0.001) as observed in the basic morning values before the sessions, but after 1 day of rest serum total and free testosterone reached (P less than 0.01 and 0.05) the pretraining level. The sessions resulted also in acute changes (P less than 0.05-0.01) in serum cortisol and somatotropin concentrations, but the basic morning levels did not change during the training period. The present findings suggest that during a short period of intense strength training the changes especially in serum testosterone concentrations indicate the magnitude of physiologic stress of training. The acute changes in serum hormone concentrations during a period of a few days do not, however, necessarily directly imply the changes in performance capacity. A longer period of follow-up lasting a few weeks is probably needed if an individual trainability status of a strength athlete is to be evaluated on the basis of the hormone determinations.
Acute neuromuscular and endocrine adaptations to weight-lifting were investigated during two successive high intensity training sessions in the same day. Both the morning (I) (from 9.00 to 11.00 hours) and the afternoon (II) (from 15.00 hours to 17.00 hours) training sessions resulted in decreases in maximal isometric strength (p less than 0.01 and less than 0.05), shifts (worsening) in the force-time curve in the absolute scale (p less than 0.05 and ns.) and in decreases in the maximal integrated EMG (p less than 0.01 and less than 0.05) of the selected leg extensor muscles. Increases in serum total (p less than 0.05) and free testosterone (p less than 0.01) and in cortisol (p less than 0.01) concentrations were found during training session II. These were followed by decreases (p less than 0.001 and p less than 0.01 and ns.) in the levels of these hormones one hour after the termination of the session. The responses during the morning training session were different with regard to the decreases in serum total testosterone (p less than 0.05), free testosterone (ns.) and cortisol (p less than 0.05). Only slight changes were observed in the levels of luteinizing hormone and sex hormone-binding globulin during the training sessions. Increases (p less than 0.01) took place in somatotropin during both training sessions. The present findings suggest that high intensity strengthening exercises may result in acute adaptive responses in both the neuromuscular and endocrine systems. The diurnal variations may, however, partly mask the exercise-induced acute endocrinological adaptations in the morning.(ABSTRACT TRUNCATED AT 250 WORDS)
Effects of fatigue on the neural activation and force production of the knee extensor muscles were investigated in 7 strength athletes during 60% concentric loading with a variable resistance D-machine. The observations were then compared with the data obtained during a corresponding loading with a normal constant resistance (CR) machine. The primary findings showed that in the CR-loading the number of repetitions (32.3±9.0) to cause fatigue was significantly (p<0.05) greater than in the D-machine (167.7±3.5) but the CR-loading was associated with a gradual decrease (p<0.05) in the knee angle of the full extension phase. The averaged integrated electromyographic activity (IEMG) of the superficial knee extensor muscles increased (p<0.05-0.01) during the course of both types of submaximal continuous fatiguing loading. However, the average shape of the IEMG-angle curve changed differently. During the final phase of the fatigue the activation of the muscles was the same for all knee angles in the D-machine, while in the CR-loading the muscle activation decreased (p<0.05) for the final knee angular phases of the extension. The fatiguing loading in the D-machine resulted in an immediate great (p<0.001) decrease in the maximal isometric force with a slight change in the maximal IEMG of the contraction. The maximal isometric force recovered only slightly during the following recovery period for 3 minutes. The present findings suggest that repeated concentric contractions of the knee extensors against a variable resistance (resulting in the actual ascending-descending shape in the force-knee angle curve) may create optimal conditions which may result in great fatigue effects on the neuromuscular system. The findings additionally indicate that fatigue under this type of experimental condition may take place primarily in the contractile processes.
Following 5 months of competitive training (approximately 9,000 yards.d-1, 6 d.wk-1), three groups of eight male swimmers performed 4 wk of either reduced training (3,000 yard.session-1) or inactivity. Two groups reduced their training to either 3 sessions.wk-1 (RT3) or 1 session.wk-1 (RT1), whereas the third group (IA) did no training. Measurement of muscular strength (biokinetic swim bench) showed no decrement in any group over the 4 wk. In contrast, swim power (tethered swim) was significantly decreased (P less than 0.05) in all groups, reaching a mean change of -13.6% by week 4. Blood lactate measured after a standard 200-yard (183 m) front crawl swim increased by 1.8, 3.5, and 5.5 mM over the 4 wk in groups RT3, RT1 and IA, respectively. In group RT1, stroke rate measured during the 200-yard swim significantly increased (P less than 0.05) from 0.54 +/- 0.03 to 0.59 +/- 0.03 strokes.-1 while stroke distance significantly decreased (P less than 0.05) from 2.50 +/- 0.08 to 2.29 +/- 0.13 m.stroke-1 during the 4-wk period. Both stroke rate and stroke distance were maintained in group RT3 over the 4 wk of reduced training. Group IA was not tested for stroke mechanics. Whereas maximal oxygen uptake decreases significantly (P less than 0.05) over the 4 wk in group RT1 (4.75 to 4.62 l.min-1), no change in maximal oxygen uptake was observed in group RT3. These results suggest that aerobic capacity is maintained over 4 wk of moderately reduced training (3 sessions.wk-1) in well-trained swimmers. Muscular strength was not diminished over 4 wk of reduced training or inactivity, but the ability to generate power during swimming was significantly reduced in all groups.
.HÄKKUKINEN, K., KOMI, P.V. & ALÉN, M. 1985. Effect of explosive type strength training on isometric force‐ and relaxation‐time, electromyographic and muscle fibre characteristics of leg extensor muscles. Acta Physiol Scand 125, 587–600. Received 26 January 1985, accepted 9 May 1985. ISSN 0001–6772. Department of Biology of Physical Activity and Department of Health Sciences, University of Jyväskylä, Finland.
To investigate the influence of explosive type strength training on isometric force‐ and relaxation‐time and on electromyographic and muscle fibre characteristics of human skeletal muscle, 10 male subjects went through progressive training which included primarily jumping exercises without extra load and with light extra weights three times a week for 24 weeks. Specific training‐induced changes in force‐time curve were observed and demonstrated by great ( P < 0.05–0.001) improvements in parameters of fast force production and by a minor ( P< 0.05) increase in maximal force. The continuous increases in fast force production during the entire training were accompanied by and correlated with the increases ( P < 0.05) in average IEMG‐time curve and with the increase (P < 0.05) in the FT:ST muscle fibre area ratio. The percentage of FT fibres of the muscle correlated ( P < 0.05) with the improvement of average force‐time curve during the training. The increase in maximal force was accompanied by significant ( P < 0.05) increases in maximum IEMGs of the trained muscles. However, the hypertrophic changes, as judged from the anthropometric and muscle fibre area data, were only slight during the training. It can be concluded that in training for fast force production considerable neural and selective muscular adaptations may occur to explain the improvement in performance, but that genetic factors may determine the ultimate potential of the trainability of this aspect of the neuromuscular performance.
Eleven male subjects (20-32 years) accustomed to strength training went through progressive, high-load strength training for 24 weeks with intensities ranging variably between 70 and 120% during each month. This training was also followed by a 12-week detraining period. An increase of 26.8% (P less than 0.001) in maximal isometric strength took place during the training. The increase in strength correlated (P less than 0.05) with significant (P less than 0.05-0.01) increases in the neural activation (IEMG) of the leg extensor muscles during the most intensive training months. During the lower-intensity training, maximum IEMG decreased (P less than 0.05). Enlargements of muscle-fibre areas, especially of fast-twitch type (P less than 0.001), took place during the first 12 weeks of training. No hypertrophic changes were noted during the latter half of training. After initial improvements (P less than 0.05) no changes or even slight worsening were noted in selected force-time parameters during later strength training. During detraining a great (P less than 0.01) decrease in maximal strength was correlated (P less than 0.05) with the decrease (P less than 0.05) in the maximum IEMGs of the leg extensors. This period resulted also in decreases (P less than 0.05) of the mean muscle-fibre areas of both fibre types. It was concluded that improvement in strength may be accounted for by neural factors during the course of very intensive strength training. Selective training-induced hypertrophy also contributed to strength development but muscle hypertrophy may have some limitations during long-lasting strength training, especially in highly trained subjects.
The purpose of this paper is to present a hypothetical model for strength training and to present supporting data. The model is an attempt to conform to the concepts of training 'periodization' and specificity of training. The model consists of four phases: (1) Hypertrophy, high volume-low intensity, (2) Basic Strength, moderate volume-high intensity, (3) Strength-Power, low volume-very high intensity (special subphases include maintenance and peaking), (4) Active Rest, very low volume-very low intensity. A review of the literature indicates that three sets of six repetitions maximum, 3 days/week is the generally recommended method of attaining maximal strength increases. However, a short term comparison (6 weeks) showed the model to be superior in producing gains in the squat (1 RM), squat/kg body weight and power as measured using the vertical jump and Lewis formula. Additionally two observations of the practical use of the model with high caliber athletes are presented. Six Olympic niveau weightlifters were observed at three competitions about 3 months apart. The 3 lifters training according to the concepts of the model showed greater improvement compared to the three using traditional methods. The second observation used a high school American-style football team. The players using the strength training model produced greater gains (bench press, squat and power) than the players using 3x6 RM over a 12 week period. The data gathered suggest that the model for strength training presented produces superior strength-power gains when compared to traditional methods.
Nine elite male junior weightlifters (mean age 17.6 +/- 0.3 yrs) performed weightlifting tests before (Test 1) and after (Test 2) 1 week of increased training volume (overreaching) and repeated the protocol after 1 year of their training program. Strength increased by Year 2 (p < 0.05) but did not change during either week of increased training volume. The 1-week overreaching stimulus resulted in attenuated exercise-induced testosterone concentrations during Year 1, but augmented exercise-induced testosterone concentrations during Year 2. Testosterone concentrations at 7 a.m. decreased for only Year 1. For both years, the 1-week overreaching stimulus increased cortisol at 7 a.m, indicative of the increased training volumes. Testosterone/cortisol was not affected by increased training volume for either year. One year of chronic weightlifting and prior exposure to the overreaching stimulus appears to decrease the detrimental effects of stressful training on the endocrine system.
To examine effects of fatiguing heavy resistance loading on voluntary neural activation and force production ten male and nine female athletes loaded their leg extensor muscles by performing 10 sets in the squat-life exercise by performing 10 repetitions in each set with the maximal load possible (about 70% of 1 RM in each set; 10*10*70%). A recovery time of 3 minutes was allowed between each set. Maximal voluntary neural activation (integrated EMG), maximal isometric force, force-time and relaxation time curves of the leg extensor muscles were measured before, during and immediately after the loading session. The maximal force was recorded also after rest for 1 hour, 2 hours, 1 day and 2 days. The relative decrease of 47.1 +/- 10.5% (p < 0.001) recorded in maximal force in males was significantly (p < 0.01) greater than the decrease of 29.4 +/- 13.8% (p < 0.001) recorded for females. Significant decreases were also observed in the maximal IEMGs of the exercised muscles both in males (p < 0.01) and females (p < 0.05). The exercise loading led also to great shifts in the shape of the force-time curve, on average, in males by 49.3 +/- 11.5% (p < 0.001) but less (p < 0.05) in females by 32.4 +/- 16.2% (p < 0.001). In males significant (p < 0.01) decreases took place also in the voluntary rapid neural activation of the exercised muscles in the IEMG-time curve. The time of force relaxation lengthened (p < 0.05) in both groups. The mean blood lactate concentration increased in males up to 15.0 +/- 4.0 mmol x 1(-1) (p < 0.001) and less (p < 0.001) in females up to 6.0 +/- 1.8 mmol x 1(-1) (p < 0.001). Maximal force recovered during the first two hours and the first day of rest less in males than in females. The present findings suggest that strenuous heavy resistance loading may result in remarkable acute fatigue in the neuromuscular system observable not only in the contractile characteristics of the exercised muscles as the decrease in force production but also by the decrease in the voluntary neural activation of the exercised muscles. In males neuromuscular fatigue may be greater and recovery from fatigue slower than in females.
Neuromuscular adaptations were investigated in ten female athletes during a "normal" intensive strength training period for 3-weeks (I) as well as during a separate second 3-week training period (II), when the same total training volume was distributed into two daily sessions. No systematic changes took place in the maximal voluntary neural activation (averaged integrated EMG) of the leg extensor muscles, in the cross-sectional area (CSA) of the quadriceps femoris muscle or in maximal voluntary isometric strength of the leg extensor muscles over training period I with one daily sessions. However, a significant increase was observed in maximal strength from 2493 +/- 553 to 2620 +/- 598 N (p < 0.05) during period II accompanied also by a significant (p < 0.05) enlargement in the cross-sectional area of the muscle and by slight (ns.) increases in the maximum IEMGs of the trained muscles. The individual changes in the maximum IEMGs of the trained muscles during period II correlated significantly (p < 0.01) with the individual changes in maximal strength. The present results with female athletes suggest that the distribution of the volume of intensive strength training into smaller units, such as two daily sessions, may create more optimal conditions not only for muscular hypertrophy but by producing effective training stimuli especially for the nervous system. These kinds of training conditions may lead to further strength development in athletes being greater than obtained during "normal" strength training of the same duration.
To examine endogenous hormonal responses to heavy-resistance exercise, ten male strength athletes performed two fatiguing but different types of sessions on separate days. In session A the loads for the leg extensor muscles in the squat-lift exercise were maximal so that the subjects performed 20 sets at 1 repetition maximum (RM) (20 x 1 RM x 100%), whereas during session B the loads were submaximal (70%) but the subjects performed each of the 10 sets until the RM (i.e., 10 repetitions/set or 10 x 10 x 70%). The recovery time between the sets was always 3 min. A decrease of 10.3 +/- 4.7% (P < 0.001) occurred in the squat-lift in 1 RM during session A, whereas session B led to a decrease of 24.6 +/- 18.9% (P < 0.001) in 10 RM. Increases in the concentrations of serum total and free testosterone (P < 0.05 and 0.05, respectively), cortisol (P < 0.001), and growth hormone (GH, P < 0.001) were observed during session B, whereas the corresponding changes during session A were statistically insignificant except for the relatively slight increase (P < 0.01) in serum GH level. The significant (P < 0.001) increase in blood lactate concentration during the two sessions correlated significantly (P < 0.01) with the increase in serum GH concentration. The morning values of serum testosterone and free testosterone were significantly (P < 0.05-0.001) lowered on the 1st and 2nd rest days after the sessions.(ABSTRACT TRUNCATED AT 250 WORDS)
To examine neuromuscular fatigue and recovery ten male and nine female athletes performed a strenuous heavy resistance exercise protocol. The subjects strained their leg extensor muscles with the same maximal relative intensity by performing one maximal squat-lift with a load of 100% of 1 RM (one repetition maximum) 20 times (20 x 1 x 100%). Maximal voluntary neural activation (integrated EMG), maximal bilateral isometric force, force-time and relaxation-time curves of the leg extensor muscles were measured before and immediately after the exercise session as well as after resting for 1 hour, 2 hours, 1 day and 2 days. The session resulted in considerable gradual decreases in maximal force in the males by 24.1 +/- 14.4% (p < 0.001) and in the females by 20.5 +/- 11.8% (p < 0.01) as recorded immediately after the session. Significant (p < 0.05-0.01) decreases also took place in the males in the maximal IEMGs of the exercised muscles, while the corresponding decreases in the females were minor. The force-time curve shifted greatly to the right both in the males (p < 0.001) and in the females (p < 0.01) but the average change of 27.8 +/- 13.8% in the males was greater (p < 0.05) than that of 18.7 +/- 8.3% recorded for the females. The time of force relaxation lengthened (p < 0.05) in both groups. Maximal force recovered during the first hour of rest was more (p < 0.05) in the females than in the males but thereafter the recovery took place gradually in both groups to the same degree.(ABSTRACT TRUNCATED AT 250 WORDS)
To examine neuromuscular fatigue and recovery 23 women, divided into three different age groups, i.e. young women (YW); 30 years (25.0 +/- 1.4; n = 8), middle-aged women (MW); 50 years (48.0 +/- 3.7; n = 7) and elderly women (EW); 70 years (68.9 +/- 3.2; n = 8) performed a strenuous heavy resistance exercise protocol. The subjects performed a bilateral leg press exercise on the machine (David 210) for 5 sets by performing 10 repetitions in each set with the maximal load possible (10 RM). A recovery time of 3 minutes was allowed between the sets. Maximal voluntary neutral activation (integrated EMG), maximal bilateral isometric force, force-time and relaxation time curves of the leg extensor muscles were measured before, between the sets, and immediately after the loading as well as resting for 1 hour, 2 hours, 1 day and 2 days. The loading led to gradual decreases in maximal force in YW by 18.8 +/- 7.1% (p < 0.001), in MW by 30.9 +/- 14.8% (p < 0.01) and in EW by 13.7 +/- 11.9% (p < 0.01) so that the relative decrease in EW was smaller (p < 0.05) than the averaged decreases in YW and MW. Significant (p < 0.05) decreases also took place in the maximal IEMGs of the exercised muscles in all groups. The force-time curve shifted also significantly both in YW (p < 0.001) and in MW (p < 0.001), while only a slight change occurred in EW. Acute recovery in maximal force was significant (p < 0.05) during the first hour of rest in YW and in MW but the force values in all groups were still after two hours of rest significantly (p < 0.05) lower than the preloading values. After two days of rest the force values were 93.7 +/- 11.5% (ns), 90.6 +/- 19.2% (p < 0.05) and 94.6 +/- 17.1% (ns) from their initial force values in YW, MW and EW, respectively. The present results suggest that strenuous heavy resistance loading both in young and middle-aged as well as in elderly women may result in considerable acute fatigue in the neuromuscular system leading not only to the decreased force production capacity of the muscles but also some decrease in the voluntary neural activation of the exercised muscles. Because the degree of acute neuromuscular fatigue and the time needed for recovery may differ considerably, there is a need to optimize the contents and the frequency of different training sessions in order to create proper strength training and for rehabilitation programs to match with the individual requirements of young, middle-aged and elderly women.
To examine acute endogenous hormonal responses to heavy resistance exercise eight young women (YW) and eight young men (YM) in the 30-year age group, seven middle-aged women (MW) and eight middle-aged men (MM) in the 50-year age group as well as eight elderly women (EW) and eight elderly men (EM) in the 70-year age group performed a heavy resistance exercise session with three different exercises (bench press, situp exercise and bilateral leg press). The relative loading intensity and volume of the exercise session were kept the same for each subject so that they performed each of the 5 sets of each exercise with the maximal load possible for 10 repetitions per set (10 repetition maximum). The recovery time between the sets was 3 minutes. The loading led to acute significant decreases in maximal isometric leg extension force by 19 +/- 7% (p < 0.001), 31 +/- 15% (p < 0.01) and by 14 +/- 12% (p < 0.01) in YW, MW and EW, respectively, and by 24 +/- 16% (p < 0.01), 34 +/- 9% (p < 0.001) and by 20 +/- 12% (p < 0.001) for YM, MM and EM, respectively. The mean concentrations of serum testosterone and cortisol remained statistically unchanged for all female groups. Significant increases took place in testosterone concentrations in YM (p < 0.05) and in MM (p < 0.01) and in cortisol in MM (p(0.01), while EM demonstrated no change at all. Serum growth hormone (GH) increased in women both in YW from 3.6 +/- 3.4 to 11.7 +/- 8.2 mu g x l(-1) (p < 0.01) and in MW from 0.3 +/- 0.1 to 6.5 +/- 5.6 mu g x l(-1) (p < 0.05), while EW demonstrated no change. In men GH concentrations increased in YM from 0.1 +/- 0.1 to 21.2 +/- 18.1 mu g x l(-1) (p < 0.05) and in MM from 0.3 +/- 0.2 to 6.0 +/- 5.4 mu g x l(-1) (p < 0.05), while EM demonstrated no change. The primary results indicate that the response of GH concentrations to the same relative heavy resistance work load is greatly lowered with increasing age both in men and women, while acute responses in testosterone levels are minor.
Overtraining is defined as an increase in training volume and/or intensity of exercise resulting in performance decrements. Recovery from this condition often requires many weeks or months. A shorter or less severe variation of overtraining is referred to as overreaching, which is easily recovered from in just a few days. Many structured training programmes utilise phases of overreaching to provide variety of the training stimulus. Much of the scientific literature on overtraining is based on aerobic activities, despite the fact that resistance exercise is a large component of many exercise programmes. Chronic resistance exercise can result in differential responses to overtraining depending on whether either training volume or training intensity is excessive. The neuroendocrine system is a complex physiological entity that can influence many other systems. Neuroendocrine responses to high volume resistance exercise overtraining appear to be somewhat similar to overtraining for aerobic activities. On the other hand, excessive resistance training intensity produces a distinctly different neuroendocrine profile. As a result, some of the neuroendocrine characteristics often suggested as markers of overtraining may not be applicable to some overtraining scenarios. Further research will permit elucidation of the interactions between the neuroendocrine system and other physiological systems in the aetiology of performance decrements from overtraining.
The purpose of this study was to examine acute neuromuscular fatigue and its recovery in men (n = 8) and women (n = 8). Two strenuous, but clearly different exercises were compared: maximal (MSL) versus explosive strength loading (ESL). The MSL included five sets of ten repetition maximum bilateral leg extensions. The same task and the same number of sets was performed in ESL but with 40% from the load used in MSL and performed as explosively as possible. Isometric force-time curves were measured during maximal voluntary bilateral isometric action of the leg extensors before the fatigue loading and after each set. The measurements were repeated after resting for 1 h, 2 h, 1 day and two days. Surface elecrtomyogram (EMG) activity was recorded from the vastus lateralis, vastus medialis and rectus femoris muscles. Blood samples from the fingertips were also taken throughout the experiment to determine blood lactate concentration. Marked changes took place in both sexes in force production during both MSL and ESL but the overall decreases were greater and the recovery was slower after MSL. Pronounced decreases occurred also in maximal integrated EMG (iEMG). In the men, the decrease in iEMG for the early contraction phase (0-100 ms) during ESL was greater (P < 0.05) than that of MSL, whereas the decrease in iEMG in the peak force phase (500-1500 ms) was similar. As expected, the increase in blood lactate concentration was greater during MSL in both sexes. It was concluded that heavy resistance loading may result in considerable acute fatigue of central and peripheral origin. The reduced electrical activity in the muscles accompanied by an accumulation of blood lactate led to marked decreases in strength. Explosive type loading, especially in men, appeared to lead primarily to central fatigue with less involvement of peripheral fatigue than MSL. The women seemed unable to fatigue themselves as much as the men, particularly in ESL.
The purpose of the study was to determine whether postactivation potentiation (PAP) was enhanced in the trained muscles of male endurance athletes.
Triathletes (TRI), distance runners (RUN), active controls (AC), and sedentary control subjects (SED) (N = 10 per group) performed 10-s maximal isometric contractions (MVC) of the elbow extensor and ankle plantarflexor muscles. Maximal twitch contractions were evoked (percutaneous stimulation) before and during a 5-min period after the MVC. PAP was measured as the percentage change in peak twitch torque post-MVC.
TRI, who train both upper and lower limb muscles, had enhanced (relative to SED) PAP in both elbow extensor and plantarflexor muscles. In RUN, who train only the lower limbs, enhanced PAP was restricted to the plantarflexors. AC, whose main activity was upper and lower limb weight training, also had enhanced PAP in both muscle groups, although the enhancement in the plantarflexors was not as great as in TRI and RUN.
PAP is enhanced in endurance athletes. Enhanced PAP may counteract fatigue during endurance exercise. The mechanism(s) responsible for the enhanced PAP remain to be determined.
To examine neuromuscular fatigue and recovery, ten male strength athletes [mean (SE) 27.5 (1.4) years] performed a moderate- and a high-intensity strength exercise protocol. In the high-intensity protocol, the load was 100% of the subject's three-repetition maximum (3-RM) for squats and front squats, and 100% of the subject's 6-RM for knee extensions. In the moderate-intensity protocol, the load was 70% of the high-intensity protocol, and both protocols lasted 90 min. The contractile properties of the leg extensor muscles were tested using isokinetic knee extensions, electrical stimulation, and squat jumps. Tests were done before exercise, 5-20 min after exercise, and frequently for 33 h after exercise. The decrements in knee extension performance were greater after the high-intensity protocol (12-14%), as compared to the moderate-intensity protocol (6-7%, P < 0.01). Similar decrements were seen in squat-jumping performance after the high-intensity protocol. Decrements in electrically evoked force were also greatest after the high-intensity protocol (P < 0.05), and were more pronounced at 20 Hz stimulation than at 50 Hz stimulation (P < 0.05). The recovery of performance showed a biphasic pattern, with a rapid recovery within the first 11 h after exercise, followed by a leveling off or a second drop in performance 11-22 h after exercise. All variables were back to baseline by 3 h after the moderate-intensity protocol, while all variables were back to baseline by 33 h after the 100% protocol. The role of structural changes (excitation-contraction coupling and contractile proteins) in the long-lasting performance decrements seen after the high-intensity protocol is discussed.