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Physiological Effects of Tapering and Detraining In World-Class Kayakers

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Abstract

This study analyzed changes in neuromuscular, body composition, and endurance markers during 4 wk of tapering and subsequent 5 wk of reduced training (RT) or training cessation (TC). Fourteen world-class kayakers were randomly assigned to either a TC (n = 7) or an RT group (n = 7). One-repetition maximum (1RM) strength, mean concentric velocity with 45% 1RM (V45%) in the bench press (BP) and prone bench pull (PBP) exercises, and body composition assessments were conducted at the start (T0) and end (T1) of a 43-wk training program, after tapering for the world championships (T2) and after TC or RT (T3). A graded exercise test on a kayak ergometer for determination of maximal oxygen uptake at T0, T1, and T3 was also performed. After tapering, no significant changes were observed in 1RM or V45%. TC resulted in significantly greater declines in 1RM strength (-8.9% and -7.8%, P < 0.05, respectively, for BP and PBP) than those observed for RT (-3.9% and -3.4%). Decreases in V45% in BP and PBP were larger for TC (-12.6% and -10.0%) than for RT (-9.0% and -6.7%). Increases in sum of eight skinfolds were observed after both TC and RT, whereas declines in maximal aerobic power were lower for RT (-5.6%) than for TC (-11.3%). Short-term TC results in large decreases in maximal strength and especially V45% in highly trained athletes. These results suggest the need of performing a minimal maintenance program to avoid excessive declines in neuromuscular function in cases where a prolonged break from training is required.

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... Leysan J. Mustafina ve ark., (2016); fiziksel olarak aktif, sağlıklı 55 erkekte 15 aday gen polimorfizmi üzerinde çalışma yapmışlardır. Fiziksel olarak aktif sağlıklı erkeklerin vastus lateralis kasından alınan biyopsi örneklerinde kas lifi tipi dağılımı ölçülmüş, ortalama olarak, yavaş kasılan (tip I) ve hızlı kasılan (tip II) liflerin nispi fraksiyonları sırasıyla%50,3 (11,5) ve 52, 8 (11,8) olarak bulunmuştur. AGTR2rs11091046 A / C polimorfizminin kas lifi bileşimi ile ilişkili olduğu gösterilmiştir [yavaş kasılan lifler için, C genotip 54.2 (11.1) %, A genotip 45.2 (10.2) %, P = 0.003; ve hızlı kasılan lifler için, C genotipi %48.9 (12.4), ...
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Giriş ve Amaç: Bu araştırmada, spor bilimleri alanında eğitim alan üniversite öğrencilerinin akademik benlik kavramı ile akademik öz-yeterlikleri arasındaki ilişkinin incelenmesi amaçlanmıştır. Yöntem: Araştırmanın evrenini Karabük Üniversitesi Hasan Doğan Beden Eğitimi ve Spor Yüksek Okulu 2.,3., ve 4. sınıf olmak üzere toplam 619 öğrenci oluştururken, örneklem grubunu ise 88’i kadın, 153’ü erkek olmak üzere toplam 241 öğrenci oluşturmaktadır. Araştırmada veri toplama aracı olarak araştırmacılar tarafından hazırlanmış “Kişisel Bilgi Formu”, üniversite öğrencilerinin akademik benlik kavramlarını ölçmek için Liu ve Wang (2005) tarafından geliştirilen, sonra Matovu (2014) tarafından üniversite öğrencileri için uyarlanan ve Cantekin ve Gökler (2019) tarafından Türkçe’ye uyarlanan “Matovu Akademik Benlik Kavramı Ölçeği” ve üniversite öğrencilerinin akademik öz-yeterliklerini ölçmek amacıyla Kandemir (2010) tarafından geliştirilen “Akademik Öz-Yeterlik Ölçeği” kullanılmıştır. Elde edilen veriler SPSS-24 Paket Programı ile analiz edilmiştir. Aynı zamanda verilerin çözüm ve yorumlanmasında Pearson korelasyon analizi, bağımsız örneklemler (Independent-Samples) T-testi analizi, One-Way ANOVA (Tek Yönlü Varyans Analizi), Tukey çoklu karşılaştırma kullanılmıştır. Bulgular: Matovu Akademik Benlik Kavramı Ölçeği (MABKÖ) toplamı ve alt boyutları ile Akademik Öz-Yeterlik Ölçeği (AÖYÖ) toplamı ve alt boyutlarının normal dağılım gösterdiği tespit edilmiştir. Öğrencilerin ölçeklerden aldıkları puanlar arasındaki ilişkiye Pearson korelasyon analizi ile bakılmıştır. Öğrencilerin MABKÖ ve alt boyutları ile AÖYÖ ve alt boyutları arasında pozitif yönde anlamlı ilişki olduğu tespit edilmiştir. Öğrencilerin cinsiyet, bölüm ve sınıf düzeylerine göre MABKÖ ve alt boyutları arasında anlamlı farklılık bulunmamaktadır. Öğrencilerin cinsiyetlerine göre AÖYÖ ve alt boyutlarından Akademik Çabaya Yönelik Öz-Yeterlik arasında anlamlı bir farklılık bulunurken, diğer alt boyutları arasında anlamlı farklılık bulunmamaktadır. Öğrencilerin bölümlerine göre AÖYÖ ve alt boyutları arasında anlamlı farklılık bulunmamaktadır. Öğrencilerin sınıf düzeylerine göre AÖYÖ toplamı ve alt boyutu olan Akademik Sorunlarla Başa Çıkmaya Yönelik Öz-Yeterlik arasında anlamlı farklılık bulunurken, diğer alt boyutları arasında anlamlı farklılık bulunmamaktadır. Anahtar Kelimeler: Akademik Benlik Kavramı, Akademik Öz-yeterlik
... Being isolated at home to prevent social interaction and the spread of the disease is among these measures (Paçenha et al., 2020 ). One of the other measures taken is to suspend or cancel all sports leagues and tournaments between mid-March 2020 and early June 2020 (Escher, 2020). All teams anticipated that their athletes 'health could be negatively affected and stated that the protection of their athletes' health is a priority issue .Page 112 / 120. ...
... It is dangerous for athletic performance if stopping the workout or significantly reducing its intensity causes a partial or complete loss of previously improved performance (Hawley and Burke., 1998). For example, it has been reported that senior male kayakers have deteriorated neuromuscular performance after 5 weeks of reduced intensity training and after complete cessation of training (García-Pallarés et al., 2010) Another study concluded that regardless of the intensity of previous endurance and resistance training, only 2-4 weeks of training interruptions can result in a significant performance loss (Muñoz-Martínez et al., 2017). Decreases in maximum and submaximal exercise performance occur within weeks after cessation of training, and these losses in aerobic performance reduce cardiovascular function and the metabolic potential of muscles (Neufer et al., 1987, Izquierdo et al., 2007. ...
... COVID-19 is thought to have physical and psychological consequences that can affect the safe return of athletes to sports and their general health, and these consequences will adversely affect the future of athletes and the sports sector and may increase the workload on health systems (Frank et al., 2020). Since most of the individuals participating in the study were athletes engaged in team sports, it was thought that there is a need for further studies comparing the level of influence of athletes who do individual and team sports from this process. ...
... During the off-season period the regular strength and conditioning training load is decreased or completely ceased. Previous evidence revealed that following a 3-8 week training cessation, endurance capacity declined [10][11][12], insulin resistance developed [13,14], body fat increased [10,13,14], muscular strength and power decreased and muscle mass loss [10,12,15] was observed in athletes from varied sporting disciplines. Detraining induced decrease in metabolic functions, particularly insulin sensitivity, can therefore weaken the post-exercise recovery process (e.g. ...
... During the off-season period the regular strength and conditioning training load is decreased or completely ceased. Previous evidence revealed that following a 3-8 week training cessation, endurance capacity declined [10][11][12], insulin resistance developed [13,14], body fat increased [10,13,14], muscular strength and power decreased and muscle mass loss [10,12,15] was observed in athletes from varied sporting disciplines. Detraining induced decrease in metabolic functions, particularly insulin sensitivity, can therefore weaken the post-exercise recovery process (e.g. ...
... During the off-season period the regular strength and conditioning training load is decreased or completely ceased. Previous evidence revealed that following a 3-8 week training cessation, endurance capacity declined [10][11][12], insulin resistance developed [13,14], body fat increased [10,13,14], muscular strength and power decreased and muscle mass loss [10,12,15] was observed in athletes from varied sporting disciplines. Detraining induced decrease in metabolic functions, particularly insulin sensitivity, can therefore weaken the post-exercise recovery process (e.g. ...
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Changes in an athlete's physiological and health metabolic profiles after detraining have not been studied in elite Taekwondo (TKD) athletes. To enable a better understanding of these physiological changes to training cessation, this study examined the effects of 8-weeks detraining on the aerobic capacity, body composition, inflammatory status and health metabolic profile in elite TKD athletes. Sixteen elite TKD athletes (age: 21.0 ± 0.8 yrs, BMI: 22.4 ± 3.9 kg/m2; Mean ± SD; 11 males and 5 females) participated in this study. Physical activity level assessment using computerized physical activity logs was performed during the competitive preparation season (i.e. one-week before national competition) and at two week intervals throughout the detraining period. Participant aerobic capacity, body fat, and blood biomarkers were measured before and after detraining, and the blood biomarker analyses included leukocyte subpopulations, blood glucose, insulin, dehydroepiandrosterone-sulfate (DHEA-S), and cortisol. Eight-week detraining increased DHEA-S/cortisol ratio (+57.3%, p = 0.004), increased insulin/cortisol ratio (+59.9%, p = 0.004), reduced aerobic power (-2.43%, p = 0.043), increased body fat accumulation (body fat%: +21.3%, p < 0.001), decreased muscle mass (muscle mass%: -4.04%, p < 0.001), and elevated HOMA-IR (the biomarker of systemic insulin resistance; +34.2%, p = 0.006). The neutrophil-to-lymphocyte ratio (NLR), a systemic inflammatory index, increased by 48.2% (p = 0.005). The change in aerobic capacity was correlated with the increased fat mass (r = -0.429, p = 0.049) but not with muscle loss. An increase in the NLR was correlated to the changes in HOMA-IR (r = 0.44, p = 0.044) and aerobic capacity (r = -0.439, p = 0.045). We demonstrate that 8-week detraining suppresses physiological stress but rapidly results in declines in athletic performance and health metabolic profiles, including reduced aerobic capacity, increased body fat, muscle loss, insulin resistance development and elevated systemic inflammatory status in these young elite TKD athletes. The inflammation state was positively associated with insulin resistance development, fat mass, WHR (the index for central fat accumulation), and the decline in VO2max.
... During the off-season period the regular strength and conditioning training load is decreased or completely ceased. Previous evidence revealed that following a 3-8 week training cessation, endurance capacity declined [10][11][12], insulin resistance developed [13,14], body fat increased [10,13,14], muscular strength and power decreased and muscle mass loss [10,12,15] was observed in athletes from varied sporting disciplines. Detraining induced decrease in metabolic functions, particularly insulin sensitivity, can therefore weaken the post-exercise recovery process (e.g. ...
... During the off-season period the regular strength and conditioning training load is decreased or completely ceased. Previous evidence revealed that following a 3-8 week training cessation, endurance capacity declined [10][11][12], insulin resistance developed [13,14], body fat increased [10,13,14], muscular strength and power decreased and muscle mass loss [10,12,15] was observed in athletes from varied sporting disciplines. Detraining induced decrease in metabolic functions, particularly insulin sensitivity, can therefore weaken the post-exercise recovery process (e.g. ...
... During the off-season period the regular strength and conditioning training load is decreased or completely ceased. Previous evidence revealed that following a 3-8 week training cessation, endurance capacity declined [10][11][12], insulin resistance developed [13,14], body fat increased [10,13,14], muscular strength and power decreased and muscle mass loss [10,12,15] was observed in athletes from varied sporting disciplines. Detraining induced decrease in metabolic functions, particularly insulin sensitivity, can therefore weaken the post-exercise recovery process (e.g. ...
... Exercise above these thresholds results in accumulation of fatigue inducing metabolites [30], rapid increases in intramuscular and arterial lactic acid, hydrogen concentration [31] and changes in motor unit recruitment [32]. Several authors have reported that long-term training programs at each of these thresholds or intensity zones will produce particular and different central and peripheral adaptations [33][34][35]. ...
... Detection of MLSS intensity is particularly important since a substantial portion of aerobic training in athletes is carried out at MLSS intensities [8,34,35,38,39,40]. Our results indicate that LT + 0.5 mMolÁL -1 during a GXT is a valid predictor of MLSS workload in well trained cyclist (p = 0.449; r = 0,78; Bias = -4.5). ...
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Purpose The purpose of this study was to determine, i) the reliability of blood lactate and ventilatory-based thresholds, ii) the lactate threshold that corresponds with each ventilatory threshold (VT1 and VT2) and with maximal lactate steady state test (MLSS) as a proxy of cycling performance. Methods Fourteen aerobically-trained male cyclists (V˙O2max 62.1±4.6 ml·kg⁻¹·min⁻¹) performed two graded exercise tests (50 W warm-up followed by 25 W·min⁻¹) to exhaustion. Blood lactate, V˙O2 and V˙CO2 data were collected at every stage. Workloads at VT1 (rise in V˙E/V˙O2;) and VT2 (rise in V˙E/V˙CO2) were compared with workloads at lactate thresholds. Several continuous tests were needed to detect the MLSS workload. Agreement and differences among tests were assessed with ANOVA, ICC and Bland-Altman. Reliability of each test was evaluated using ICC, CV and Bland-Altman plots. Results Workloads at lactate threshold (LT) and LT+2.0 mMol·L⁻¹ matched the ones for VT1 and VT2, respectively (p = 0.147 and 0.539; r = 0.72 and 0.80; Bias = -13.6 and 2.8, respectively). Furthermore, workload at LT+0.5 mMol·L⁻¹ coincided with MLSS workload (p = 0.449; r = 0.78; Bias = -4.5). Lactate threshold tests had high reliability (CV = 3.4–3.7%; r = 0.85–0.89; Bias = -2.1–3.0) except for DMAX method (CV = 10.3%; r = 0.57; Bias = 15.4). Ventilatory thresholds show high reliability (CV = 1.6%–3.5%; r = 0.90–0.96; Bias = -1.8–2.9) except for RER = 1 and V-Slope (CV = 5.0–6.4%; r = 0.79; Bias = -5.6–12.4). Conclusions Lactate threshold tests can be a valid and reliable alternative to ventilatory thresholds to identify the workloads at the transition from aerobic to anaerobic metabolism.
... La influencia del ejercicio físico en sujetos sometidos a entrenamiento tiene efectos beneficiosos en la condición física, la composición corporal (CC) y el perfil lipídico; sin embargo, el desentrenamiento (DT) tiene un efecto desfavorable en todos ellos (1,2). Las consecuencias del DT son complejas y caracterizadas por diferentes ritmos de desadaptación, como son la disminución de la fuerza, la potencia y el equilibrio (2), y, en general, por sus efectos sobre la disminución de la función neuromuscular (3). ...
... Los cambios significativos del porcentaje de grasa corporal total tras el DT están en concordancia con los datos aportados por otros autores en diversas modalidades deportivas y tras periodos de DT (3,4,6,9,14). El ligerísimo aumento no significativo de la MME podría ser debido a la asociación del ACT con la masa muscular y sus componentes tanto extra como intracelular que se observa tras el DT, habiéndose descrito modelos de regresión múltiple de los cambios del peso corporal a través de cambios del AEC que explicarían un 55% de la varianza en el cambio del peso corporal (13). ...
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Introducción: la influencia del ejercicio físico en sujetos entrenados tiene efectos beneficiosos en la condición física y la composición corporal. Sin embargo, el desentrenamiento tiene un efecto desfavorable en todas ellas. Objetivo: el propósito del estudio fue analizar los cambios de la composición corporal después de un periodo de desentrenamiento de seis semanas de duración en dos grupos: uno de 43 jóvenes varones jugadores de fútbol (grupo experimental [GE], n = 43), y un grupo control de escolares no activos de la misma edad (grupo control [GC], n = 10). Métodos: las variables de composición corporal fueron evaluadas mediante antropometría, para estimar la masa grasa (MG) y la masa muscular esquelética (MME), y mediciones de bioimpedancia eléctrica, para estimar agua corporal total (ACT), agua extra (AEC) e intracelular (AIC). Las mediciones se realizaron tanto en situación de entrenamiento como de desentrenamiento. Resultados: tras el desentrenamiento, se encontraron diferencias significativas en el ACT (35,5 ± 5,2 vs. 36,7 ± 4,9 kg), el AIC (14,2 ± 1,8 vs. 14,8 ± 1,6 kg) y el AEC (21,5 ± 3,6 vs. 22,0 ± 3,4 kg, p < 0,001 para todas las variables), sin existir diferencias en los ratios AEC/ACT (0,4 ± 0,02 vs. 0,4 ± 0,02) y AIC/ACT (0,6 ± 0,02 vs. 0,597 ± 0,02, ambos p > 0,05). La MG aumentó significativamente (8,6 ± 3,2 vs. 8.95 ± 3,1 kg, p < 0,01); sin embargo, la MME no sufrió modificaciones (21,2 ± 2,5 vs. 22,22 ± 2,8 kg, p > 0,05) Conclusiones: el principal resultado de este estudio fue que en un periodo de desentrenamiento de seis semanas se observaron aumentos del ACT y de su distribución en el grupo de jóvenes futbolistas. La importancia fisiológica de esta desadaptación en el rendimiento deportivo tiene que ser analizada en futuros estudios.
... 11 after short-term Tc, several studies have reported a reduction in the maximal oxygen consumption (Vo 2 max), time to exhaustion at a fixed intensity, plasma volume and increased hr at the second ventilatory threshold, in endurance athletes. 12,13 although these aforementioned chronic responses have been extensively described in the literature, less is known about the possible adaptations caused by a short period of Tc (i.e., 4-weeks) in the time-trial performance and vagally-mediated indices in high-level endurance athletes. in this regard, investigating the specific performance changes after TC would help coaches to control the variations in athleticism -which possibly occur during the transition periods -and develop better training strategies during the earlier phases of the training cycle (when the ath-Heart rate variability analysis approximately 2-min was provided for participants receiving the specific instructions, taking place in the seated position and fitting the chest strap. ...
... our data are in agreement with a series of previous studies that reported impairments in aerobic performance and physiological traits of endurance athletes after short-periods of detraining. 11,12,23,24 importantly, in this study, we used magnitude-based inference calculation, whereas the cited studies used traditional parametric analyses. it is probable that the decreases in the 3000 m time-trial performance were associated with the reduction in the Vo 2 max and ventilatory thresholds, which, in turn, are highly correlated with middle-and long-distance endurance performances. ...
Article
Background: The purpose of this study was to analyze the effects of four weeks of training cessation (TC) on specific endurance performance, resting and post-exercise heart rate variability (HRV) and neuromuscular capacities of high-level endurance runners. Methods: Eighteen endurance runners, 8 men and 10 women (25.5 ± 7.5 years; 166.9 ± 7.6 cm; 54.2 ± 6.9 kg), took part in this study. The 3000 m time trial performance, resting HRV, 5'-5' test, squat and countermovement jumps (SJ and CMJ, respectively) and mean propulsive power in the jump squat exercise relative to body mass (MPP JS REL) were performed pre and immediately following the 4-week TC. The inference based on magnitudes were used to analyze the differences between pre and post values. Results: The time in the 3000 m time-trial was almost certainly higher after TC. A very likely decrease was noticed in the resting HRV index after the TC period. The differences in all variables analysed during the 5'-5' test were rated as unclear. No differences were observed in SJ and CMJ comparing the pre and post moments of TC, while the MPP JS REL was very likely improved after the TC period. Conclusion: The resting HRV accompanied the reductions in the specific endurance performance while the 5'-5' test variables did not. The lack of training stimulus led to improvement in the MPP JS REL, possibly due to the withdrawal of specific endurance training, which strongly concurs with neuromuscular performance.
... This study found that the maximum oxygen uptake in the reduced training group was reduced by~10%, which was less than that in the training cessation group (~18%) [25]. Our results are also consistent with the findings in other exercise model athletes, e.g., in well-trained endurance athletes [26,27], soccer players [28], and team players [29], the maximal oxygen uptake decreased significantly after 2-8 weeks of reduced training. In addition, a recent study found that taekwondo training is effective in improving VO 2 max [15], and it is possible that the lack of taekwondo combat training might have a negative impact on aerobic endurance performance. ...
... However, not all studies exhibited consistent findings. In a study of 14 worldclass Kayaking athletes, it was found that after five weeks of reduced training or cessation of training, the bodyweight of athletes in the reduced training group remained unchanged, but decreased significantly by 3% in the stop training group [26]. In addition, that study found that the two-week cessation of training for excellent football players in the off-season did not make significant changes in body composition [9]. ...
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Background: The global coronavirus disease pandemic (COVID-19) has had a considerable impact on athletic competition and team sports training. Athletes have been forced to train alone at home. However, the isolation training model effects are still unknown. Purpose: This study compared the effects of personal isolation training (PIT) and detraining (DT) on specific sport performances (flexibility, power, reaction time, acceleration, and aerobic capacity) and body composition in elite taekwondo athletes. Methods: Eleven elite taekwondo athletes were recruited as voluntary subjects. Athletes were randomly paired by weight into the personal isolation training group (PIT group: N = 5, age: 21.2 ± 0.4 years, BMI: 22.2 ± 0.8 kg/m2) or detraining group (DT group: N = 6, age: 19.8 ± 0.3 years, BMI: 23.1 ± 1.0 kg/m2). All subjects performed the same training content prior to the pre-test (T1). When the pre-test was completed, all subjects underwent 12 weeks of PIT or DT. Athletes were then administrated the post-test (T2). The athlete's sport performances and body composition were measured to compare the differences between the two groups (PIT and DT) and two phases (T1 and T2). Results: There were no significant differences in kicking reaction time and flexibility in both groups (p > 0.05). The PIT showed significant improvements in 10 m (10M) sprint performance (p < 0.05), and displayed a progress trend in Abalakov jump performance. In addition, the PIT resulted in a better change response in 10M sprint performance (PIT: -4.2%, DT: +2.1%), aerobic endurance performance (PIT: -10.2%, DT: -18.4%), right arm muscle mass (PIT: +2.9%, DT: -3.8%), and trunk muscle mass (PIT: +2.2%, DT: -1.9%) than DT (p < 0.05). The fat mass percentage showed a negative change from T1 to T2 in both groups (p < 0.05). Conclusions: PIT showed a trend toward better body composition (arm and trunk muscle) and sport performances (10M sprint and aerobic capacity) compared to DT. This finding may provide information on the effectiveness of a personal isolation training model for optimal preparation for taekwondo athletes and coaches. It may also serve as a useful and safe guideline for training recommendations during the coronavirus disease (COVID-19).
... Confirming our last hypothesis, the results of the external validity showed high agreement of F0 with corresponding variables obtained from traditional exercises commonly used for testing kayakers (bench press and prone bench pull) and Pmax with the maximal power reached during the modified Wingate test on a kayak ergometer (García-Pallarés et al., 2010;Papandreou et al., 2018;Van Someren and Howatson, 2008). Finally, while the external validity of V0 obtained during the SKST was high with respect to V0 obtained during the prone bench pull, the agreement of V0 with the same variable from the bench press ranged from low to moderate. ...
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The assessment of the force-velocity (F-V) profile in athletes may have important applications for training prescription, injury management, and fatigue monitoring. This study aimed to assess whether a novel single kayak stroke test (SKST) is able to provide the F-V relationship variables (maximum force, maximum velocity and maximum power) of competitive kayakers with acceptable reliability and external validity. Six female (age: 20.3 ± 3.7 years) and eight male (age: 20.8 ± 2.4 years) elite kayakers performed the SKST, bench press, bench pull, and short Wingate kayak test. The individual F-V relationships were highly linear [median r (range): left stroke = 0.986 (0.897-0.998); right stroke = 0.987 (0.971-0.999)]. The reliability of the F-V relationship parameters obtained during the SKST was high (within-session: CV ≤ 4.48% and ICC ≥ 0.93; between-session: CV ≤ 8.06% and ICC ≥ 0.65). The validity of the F-V relationship parameters obtained during the SKST was generally very high for maximum power (r range = 0.825-0.975), high for maximum force during both the bench press and the bench pull (r range = 0.751-0.831), and high or moderate for maximal velocity during the bench pull (r = 0.770-0.829) and the bench press (r = 0.355-0.471), respectively. The SKST can be considered a feasible procedure for testing the maximal upper-body muscle mechanical capacities of kayakers.
... Also, just like Pallarés et al. (24), the current study found greater strength reductions against maximal loads (1RM) than against submaximal loads (MPV ALL ). In relation to this aspect, other studies supported that submaximal strength may be much more rapidly lost than maximal strength, after finding larger reductions on strength performance against light-medium loads than high loads (6,12,13). These contradictory results could be explained by the differences in methodological aspects such as the exercises tested, the durations of the training cessation, or the subjects' experience. ...
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Martínez-Cava, A, Hernández-Belmonte, A, Courel-Ibáñez, J, Morán-Navarro, R, González-Badillo, JJ, and Pallarés, JG. Bench press at full range of motion produces greater neuromuscular adaptations than partial executions after prolonged resistance training. J Strength Cond Res XX(X): 000-000, 2019-Training at a particular range of motion (ROM) produces specific neuromuscular adaptations. However, the effects of full and partial ROM in one of the most common upper-limb exercises such as the bench press (BP) remain controversial. In this study, 50 recreationally to highly resistance trained men were randomly assigned to 1 of 4 training groups: full bench press (BPFULL), two-thirds bench press (BP2/3), and one-third bench press (BP1/3) and control (training cessation). Experimental groups completed a 10-week velocity-based resistance training program using the same relative load (linear periodization, 60-80% 1 repetition maximum [1RM]), only differing in the ROM trained. Individual ROM for each BP variation was determined in the familiarization and subsequently replicated in every lift during training and testing sessions. Neuromuscular adaptations were evaluated by 1RM strength and mean propulsive velocity (MPV). The BPFULL group obtained the best results for the 3 BP variations (effect size [ES] = 0.52-1.96); in turn, partial BP produced smaller improvements as the ROM decreased (BP2/3: ES = 0.29-0.78; BP1/3: ES = -0.01 to 0.66). After 10-week of training cessation, the control group declined in all neuromuscular parameters (ES = 0.86-0.92) except in MPV against low loads. Based on these findings, the BPFULL stands as the most effective exercise to maximize neuromuscular improvements in recreational and well-trained athletes compared with partial ROM variations.
... 9,11 Height, body mass index, body fat percentage and lean body mass play an important role in the TKD branch. 12,13 In addition, since TKD is a weight sport, relative strength is an important element. 13 Therefore, athletes pay attention to their body composition in order to compete in the weight class they determine and become successful. ...
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Background: Taekwondo (TKD) is a combat sport practiced by millions of children, young people and adults around the world.1 It is an Olympic sports branch with many complex features and constant interaction between two opponents in the competitions, where attack-contact techniques are applied quickly, attacking techniques are strong2,3 but also have good flexibility. Aim: This study has been carried out to identify the relationship between body composition of taekwondo practitioners aged 14-16 who regularly practice taekwondo, and their aerobic endurance. Methods: A total of 33 registered taekwondo practitioners (17 male, 16 female) participated to this study on a voluntary basis. The age, height, weight, and body mass index of all the athletes who took part in the study are 14.96±0.80 years, 162.59±11.59 cm, 50.97±7.51 kg and 19.14±2.39 kg/m² respectively. The group who participated to the study practice taekwondo two days a week, for 2 hours each, for a period of 1.5 years. The aerobic endurance of taekwondo athletes was measured by 20-meter-long Shuttle Run Test. In order to measure the body composition values of the athletes, measurements of skinfold thickness (biceps, triceps, subscapula, subrailiac) were carried out. In calculating the body density, the formula of Durning-Womersley was used; and in calculating the body fat percentage, the formula of Siri was employed. Data was evaluated by SPSS 22.0. The normality distribution of the data obtained at the end of the study was evaluated by Kolmogorov-Smirnov test and it was observed that the data was in line with normal distribution. Following the normalcy assessment, the relationship between body compositions and aerobic endurances was determined by Pearson Correlation analysis. Results: It is possible to say that the body composition values of taekwondo practitioners aged 14-16 have positive and negative impact on their aerobic endurance. It is observed that as the values 20-meter Shuttle Run test increases, fat percentage of athletes decreases. Conclusion: It is concluded that the findings obtained from the research results support the literature, and that body composition and aerobic capacity are important as performance criteria in many studies. It is thought that it may be beneficial for the athletes to perform aerobic endurance exercises during the annual training periods to perform the necessary practices to optimize their body composition and improve their aerobic capacity. Keywords: Taekwondo, Body Composition, Aerobic Endurance
... The effects of training cessation have been investigated in athletes such as soccer players (Koundourakis et al., 2014), swimmers (Ormsbee & Arciero, 2012), kayakers (Garcia-Pallares, Sanchez-Medina, Perez, Izquierdo-Gabarren, & Izquierdo, 2010), handball players (Marques & Gonzalez-Badillo, 2006), rowers (Godfrey, Ingham, Pedlar, & Whyte, 2005) and runners (Houmard et al., 1992), but data are scarce in cycling after a period of long-term detraining. Thus, studies are needed, first to demonstrate the effects of cessation of training in a sport where physiological markers are determinants of performance, and second to challenge the traditional training concepts in young cyclists. ...
Article
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In cycling, it is common practice to have a break in the off season longer than 4 weeks while adopting an almost sedentary lifestyle, and such a break is considered to be long-term detraining. No previous studies have assessed the effect of training cessation with highly trained young cyclists. The purpose of the present investigation was to examine effects of 5 weeks of training cessation in 10 young (20.1 ± 1.4 years) male road cyclists for body composition, haematological and physiological parameters. After training cessation, body mass of cyclists increased (P = 0.014; ES = 0.9). V_O2max (L ·min−1 = −8.8 ± 5.0%,mL · kg−1·min−1 = −10.8 ± 4.2%,), Wmax (W = −6.5 ± 3.1%, W · kg−1 = −8.5 ± 3.3%,), WLT1 (W = −12.9 ± 7.0%, W · kg−1 = −14.8 ± 7.4%,), WLT2 (W = −11.5 ± 7.0%, W · kg−1 = −13.4 ± 7.6%,) and haematological (red blood cells count, −6.6 ± 4.8%; haemoglobin, −5.4 ± 4.3% and haematocrit, −2.9 ± 3.0%) values decreased (P ≤ 0.028; ES ≥ 0.9). Five weeks of training cessation resulted in large decreases in physiological and haematological values in young top-level road cyclists suggesting the need for a shorter training stoppage. This long-term detraining is more pronounced when expressed relative to body mass emphasising the influence of such body mass on power output. A maintenance programme based on reduced training strategies should be implemented to avoid large declines in physiological values in young cyclists who aspire to become professionals.
... Hence, although football referees had 4 weeks to retrain after lockdown, the current data suggest that it was an insufficient training stimulus to compensate the detraining effect of 8 weeks of home confinement. These performance decrements coincided with the decline in cardiovascular and functional performance in elite athletes with more than 5 weeks of exercise inactivity [15]. This is further confounded by the fact that physical performance is lower at the beginning of the season and the teams needed approximately 8-10 matchdays to reach a steady-state running performance, as recently identified in professional players [4]. ...
Article
To investigate the effect of COVID-19 lockdown on match-play metrics in professional football referees during official matches of the Spanish professional leagues. Forty-two professional football referees from the First (n = 20) and Second Division (n = 22) were monitored during 564 official games using Global Positioning System (GPS) technology. Data of matches before lockdown were compared to matches after resumption of the competition. Compared to pre-lockdown, in the referees of the First Division there was a decrease in the total running distance and the distance covered at all speed thresholds > 6 km ·h-1 after lockdown (P < .05). In the Second Division referees, the post-lockdown measurement only showed a decrease in the running distance at 21–24 km·h-1 (P < .05), with no changes in the other speed thresholds. The postlockdown measurement showed an increased distance covered at < 6 km·h-1 and the number of accelerations or both First and Second Division referees (P < .05). Referees’ match activity was reduced due to the COVID-19 ockdown, while the effect on running parameters was more pronounced in First Division referees.
... submaximal level of effort) has been proved adequate to achieve positive neuromuscular and morphological adaptations (4,6,17,19,23,25) and, perhaps most importantly, to enhance specific athletic performance (8-10, 17, 23, 24). All these findings suggest that there are important shortcomings associated to training to failure protocols, mainly related to the slowdown of the mechanical and biochemical recovery (12,22), that may be detrimental for competitive athletes, especially in sports where very rapid movements and explosive force production are key for performance (23) or in those characterized by concurrent strength and endurance training (9,10,17). ...
Article
This study analyzed whether the loss of repetition velocity during a resistance exercise set was a reliable indicator of the number of repetitions left in reserve. Following the assessment of one-repetition (1RM) strength and full load-velocity relationship, thirty men were divided into three groups according to their 1RM strength/body mass: novice, well-trained and highly-trained. On two separate occasions and in random order, subjects performed tests of maximal number of repetitions to failure against loads of 65%, 75% and 85% 1RM in four exercises: bench press, full squat, prone bench pull and shoulder press. For each exercise, and regardless of the load being used, the absolute velocities associated to stopping a set before failure, leaving a certain number of repetitions (2, 4, 6 or 8) in reserve, were very similar and showed a high reliability (CV 4.4-8.0%). No significant differences in these stopping velocities were observed for any resistance training exercise analyzed between the novice, well-trained and highly-trained groups. These results indicate that by monitoring repetition velocity one can estimate with high accuracy the proximity of muscle failure and, therefore, to more objectively quantify the level of effort and fatigue being incurred during resistance training. This method emerges as a substantial improvement over the use of perceived exertion to gauge the number of repetitions left in reserve.
... Previous evidence obtained from endurance athletes reveal that 3-8 weeks of insufficient physical activity would result in insulin resistance development [2,3,19], which is in line with our findings from retired combative athletes. On the other hand, the increase in circulating platelets has been documented in individuals with metabolic syndrome [20] and type 2 diabetes [21]. ...
Article
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Background This study used a short-term de-training model to mimic the physiological weight changes during the early retirement stage in Taekwondo (TKD) athletes. This study investigates whether the negative changes in body composition, blood lipid profiles, and metabolic biomarkers occur in elite collegiate TKD athletes when experiencing a two-months de-training period. Methods Fourteen collegiate Division Ι elite TKD athletes (age: 21.1 ± 0.2 years, BMI: 22.3 ± 1.1 kg/m²; 10 males and 4 females) participated in this study. The body composition, blood lipid profiles, atherogenic dyslipidemia indexes, metabolic biomarkers and baseline systemic inflammation states were measured before and after two-months de-training. Results The body weight and BMI did not change after de-training in these elite TKD athletes. The total muscle mass displayed a significant decline after de-training (−2.0%, p = 0.019), with an increase in fat mass (+24.3%, p < 0.01). The blood triglyceride did not change, but the total cholesterol was higher after de-training (+8.3%, p = 0.047). The CHOL-to-HDL and LDL-to-HDL ratios increased by 12.4% (p < 0.001) and 13.2% (p = 0.002) after de-training, respectively. The blood platelet number, plateletcrit, and platelet-to-lymphocyte ratio increased significantly by 5.0% (p = 0.013), 7.3% (p = 0.009), and 20.6% (p = 0.018) after de-training, respectively. The McAuley’s Index decreased (−6.9%, p = 0.025) after de-training. Conclusion We demonstrated that a two-months de-training period resulted in adverse effects on early atherogenic dyslipidemia development, progressing insulin resistance, low-grade inflammation, and visceral adiposity in young elite TKD athletes. Our findings provide clear insights into the possible deleterious impacts at early stage retirement in former combative sports athletes.
... A number of studies with adults have demonstrated that detraining can diminish the training-induced muscular performance enhancements (i.e., strength, muscle activation, and cross-sectional area [CSA]) relatively quickly to baseline values (8). For example, this return to baseline has been reported with 4, 12, and 16 weeks of training with 4-8 weeks of detraining (20,23,28,29), 3 months of training followed by 3 months of detraining (1,2,32). Not all adult detraining studies demonstrate loss of training-induced adaptations. ...
Article
Global (whole body) effects of resistance training (i.e., cross-education) may be pervasive with children. Detraining induces less substantial deficits with children than adults. It was the objective of this study to investigate the global responses to 4-weeks of detraining after 8-weeks of unilateral leg press (LP) training in 10-13-year-old, prepeak- height-velocity stage boys. Subjects were randomly separated into two unilateral resistance training groups (high load/low repetitions: (HL-LR) and low load/high repetitions (LL-HR) and control group. Assessments at pre-training, post-training and detraining included dominant and non-dominant limbs, unilateral, one repetition maximum (1RM) and 60% 1RM LP, knee extension, knee flexion, elbow flexion, and handgrip maximal voluntary isometric contraction (MVIC), and countermovement jump (CMJ). All measures significantly increased from pre-test to detraining for both training programs except for elbow flexion MVIC with increases only with HL-LR. All measures except CMJ and handgrip MVIC significantly decreased from post-test to detraining except for elbow flexion MVIC with decreases only with HL-LR. The dominant trained limb experienced significantly greater LP improvements (pre- to detraining) and decrements (post- to detraining) with LP 1RM and 60% 1RM LP. In conclusion, youth HL-LR and LL-HR global training effects of trained and untrained limbs demonstrate similar benefits (pre- to detraining) and decrements (post- to detraining) with detraining. The findings emphasize that training any muscle group in a child can have positive global implications for improved strength and power that can persist over baseline measures for at least a month.
... In addition, interference in the improvement of physical fitness is usually observed only during a long (>7-8 weeks) training period (Hickson, 1980;Izquierdo et al., 2003). In studies where the training frequency have not exceeded 3 days per week, increases in maximum strength were detected following concurrent training periods between 8 and 16 weeks McCarthy et al., 2002) and ≥20 weeks ( García-Pallarés et al. 2010;Häkkinen et al., 2003). This is consistent with Sillanpää and colleagues (2008) that analyzed the effects of a 21-weeks (twice a week) of resistance and/or aerobic training on body composition and physical fitness of older man. ...
Article
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This paper affords an update review over the state of art regarding the importance of physical fitness and the significance of different combination approaches between resistance and aerobic training, as well as conditioning methods exercise alone on physical fitness improvements, specifically explosive strength and cardiorespiratory fitness in prepubertal children. The main research conclusions can be summarized as: i) Resistance training can be reliable to improve muscle strength in prepubertal children; ii) A proper and quantifiable exercise frequency and intensity in aerobic training remains unclear; iii) No differences have been found between prepubertal girls and boys on strength and aerobic capacity improvements after intra-session concurrent training, resistance or aerobic training alone; iv) In adults, concurrent resistance and aerobic training seems to be more effective on improvements of aerobic capacity than aerobic training alone; v) Aerobic training biomechanically specific to the concurrent resistance training may minimize adaptation interference when concurrently training; vi) In adolescents, concurrent resistance and aerobic training is equally effective to improve explosive strength compared to resistance training alone, and more efficient in aerobic capacity than resistance training alone; vii) Optimum training sequence was determined by the individual purposes of the training program; viii) Performing aerobic prior to resistance training produces endurance gains, while performing resistance prior to aerobic training appears to be more adequate to obtain strength improvements; ix) In adults, performing concurrent training in different sessions seems to be more effective to improve muscular strength than intra-session concurrent training. These results can be helpful for coaches, teachers and researchers to optimize explosive strength and cardiorespiratory fitness training in sports club and school-based programs, as well as a reliable source for further researches.
... nt of physical fitness is usually observed only during a long (>7-8 weeks) training period (Hickson, 1980;Izquierdo et al., 2003). In studies where the training frequency have not exceeded 3 days per week, increases in maximum strength were detected following concurrent training periods between 8 and 16 weeks McCarthy et al., 2002) and ?20 weeks ( Garc?a-Pallar?s et al. 2010;H?kkinen et al., 2003). This is consistent with Sillanp?? and colleagues (2008) that analyzed the effects of a 21-weeks (twice a week) of resistance and/or aerobic training on body composition and physical fitness of older man. The authors observed similar gains in maximal concentric force in the resistance training (+ 22.0%) and concurr ...
Article
Full-text available
This paper affords an update review over the state of art regarding the importance of physical fitness and the significance of different combination approaches between resistance and aerobic training, as well as conditioning methods exercise alone on physical fitness improvements, specifically explosive strength and cardiorespiratory fitness in prepubertal children. The main research conclusions can be summarized as: i) Resistance training can be reliable to improve muscle strength in prepubertal children; ii) A proper and quantifiable exercise frequency and intensity in aerobic training remains unclear; iii) No differences have been found between prepubertal girls and boys on strength and aerobic capacity improvements after intra-session concurrent training , resistance or aerobic training alone; iv) In adults, concurrent resistance and aerobic training seems to be more effective on improvements of aerobic capacity than aerobic training alone; v) Aerobic training biomechanically specific to the concurrent resistance training may minimize adaptation interference when concurrently training; vi) In adolescents, concurrent resistance and aerobic training is equally effective to improve explosive strength compared to resistance training alone, and more efficient in aerobic capacity than resistance training alone; vii) Optimum training sequence was determined by the individual purposes of the training program; viii) Performing aerobic prior to resistance training produces endurance gains, while performing resistance prior to aerobic training appears to be more adequate to obtain strength improvements; ix) In adults, performing concurrent training in different sessions seems to be more effective to improve muscular strength than intra-session concurrent training. These results can be helpful for coaches, teachers and researchers to optimize explosive strength and cardiorespiratory fitness training in sports club and school-based programs, as well as a reliable source for further researches.
... at the muscular level, short-term detraining reduces enzymatic activity and fibre cross-sectional area as well as neuromuscular function and fat-free mass. 12,13 previous studies have demonstrated a significant decrease in jumping performance after plyometric training 14 or muscular strength after vibration/low velocity training 15 subsequently a detraining period of 4 weeks. on the other hand, higher intensity strength protocols (which may include kettlebell training) induces greater gains in strength and anaerobic power and may maintain the gains for prolonged periods (48 weeks) after training cessation. ...
Article
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BACKGROUND: Traditional strength and power training could be expensive and kettlebell exercise may be a more affordable, accessible, and low cost alternative. However, requires appropriate technique and intensity and could be difficult for novice users. Our aims were to evaluate the influence of systematized kettlebell training on strength and power variables and the effects of short-term detraining and determine the intensity training profile in all protocol phases. METHODS: Healthy and physically active women - without kettlebell experience (N.=17, body mass: 60.9±12.5 kg; height: 164.6±5.5 m; age: 26.0±5.0 years; body mass index: 22.3±3.8 kg/m²) were recruited. The study was organized in five successive phases: pre-kettlebell training (PRE), kettlebell training period (12 weeks), post-kettlebell training (POST), detraining period (four weeks), and evaluations post-kettlebell detraining (POST-D). The Wingate anaerobic test, standing long jump, abdominal strength, leg press, and handgrip strength tests were used. The training intensity it was controlled by rated of perceived exertion (RPE) and heart rate (HR). RESULTS: Absolute mean anaerobic power at POST was significantly (P<0.05) higher when compared to PRE. Relative mean power at POST-D was significantly (P<0.05) higher when compared to PRE. Jumping performance and lower limb and handgrip strengths were higher at POST than PRE. All of these variables were significantly (P<0.05) higher at POST-Dwhen compared to PRE. It was possible to classify the applied protocol, in the studied population, as of moderate intensity (by HR) and effort low to very intense (by RPE). CONCLUSIONS: Twelve weeks of kettlebell training improved maximal and isometric strength and muscle power and short-term detraining was not sufficient to reverse these positive adaptations in physically active and healthy women.
... Longer periods without strength training (12 weeks) may lead to reduced strength of 7-12% in strength trained individuals (Mujika and Padilla, 2000). Importantly, small quantities of training can attenuate the strength loss following complete training cessation in high levels athletes (García-Pallarés et al., 2010). Our planned data collection involving female football players was abruptly interrupted by the pandemic. ...
Article
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Introduction: The COVID-19 outbreak with partial lockdown has inevitably led to an alteration in training routines for football players worldwide. Thus, coaches had to face with the novel challenge of minimizing the potential decline in fitness during this period of training disruption. Methods: In this observational pre-to posttest study involving Norwegian female football players (18.8 ± 1.9 years, height 1.68 ± 0.4 m, mass 61.3 ± 3.7 kg), we investigated the effects of a prescribed home-based and group-based intervention, implemented during the COVID-19 lockdown, on maximal muscular force production and high velocity variables. Specifically, maximal partial squat strength one repetition maximum (1RM), counter movement jump (CMJ) and 15 m sprint time were assessed 1 week prior to the lockdown and 12 weeks after the onset of lockdown. We also collected training content and volume from the prescribed training program and self-reported perceived training quality and motivation toward training. Results: We observed no change in 1RM [pretest: 104 ± 12 kg, posttest: 101 ± 11 kg (P = 0.28)], CMJ height [pretest: 28.1 ± 2.3 cm, posttest: 26.8 ± 1.9 (P = 0.09)], and 15 m sprint time [pretest: 2.60 ± 0.08 s, posttest: 2.61 ± 0.07 s (P = 0.52)]. Conclusion: Our findings suggest that a prescribed home-based and group-based intervention with increased training time devoted to strength, jump, and sprint ability, and regulated to obtain a sufficient infection control level is feasible and effective to preserve strength, jumping, and sprinting abilities of high-level female football players during a ∼ 3-month period of a pandemic-induced lockdown.
... No obstante, conviene matizar que, tanto la frecuencia cardiaca como la potencia, proporcionan información diferente y complementaria. Como prueba de esto, distintos autores (Garcia-Pallares, Sanchez-Medina, Carrasco, Diaz, & Izquierdo, 2009;Garcia-Pallares, Sanchez-Medina, Esteban Perez, Izquierdo-Gabarren, & Izquierdo, 2010;Lucía, Hoyos, Pérez, & Chicharro, 2000) comprobaron que los valores de FC correspondientes a diferentes hitos fisiológicos relacionados con el rendimiento deportivo (VT1,VT2 y PAM), permanecieron estables durante el transcurso de un año completo de entrenamiento, a pesar de las adaptaciones funcionales significativas producidas por el entrenamiento en cada hito fisiológico. ...
Thesis
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The doctoral thesis presented in this document is structured in three different parts. The first part of the work is composed of studies I and II, where the validation work of two different workload cycling tools, “drive indoor trainer Cycleops Hammer” and “PowerTap P1 Pedals Power Meter “, is detailed. In both articles, randomized and counterbalanced incremental workload tests (100-500 W) were performed, at 70, 85 and 100 rev·min-1 cadence, with sitting and standing pedalling in 3 different Hammer unit cadences. Then, the results are compared against the values measured by a professional SRM crankset. In general terms, no significant differences were detected between the Hammer devices and the SRM, while strong intraclass correlation coefficients were observed (≥0.996; p=0.001), with low bias (-5,5 a 3,8), and high values of absolute reproducibility (CV<1,2%, SEM<2,1). The PowerTap P1 pedals showed strong correlation coefficients in a seated position (rho ≥ 0.987). They underestimated the power output obtained in a directly proportional way to the cadence, with an average error of 1.2%, 2.7%, 3.5% for 70, 85 and 100 rev∙min-1. However, they showed high absolute reproducibility values (150-500 W, CV = 2.3%, SEM <1.0W). These results prove that both are valid and reproducible devices to measure the power output in cycling, although caution should be exercised in the interpretation of the results due to the slight underestimation. The second part of the thesis is devoted to the study III, where the time to exhaustion (TTE) at the workloads related to the main events of the aerobic and anaerobic pathway in cycling were analysed in duplicate in a randomized and counterbalanced manner (Lactic anaerobic capacity (WAnTmean), the workload that elicit VO2max -MAP-, Second Ventilatory Threshold (VT2) and at Maximal Lactate Steady State (MLSS). TTE values were 00:28±00:07, 03:27±00:40, 11:03±04:45 and 76:35±12:27 mm:ss, respectively. Moderate between-subject reproducibility values were found (CV=22.2%,19.3%;43.1% and 16.3%), although low within-subject variability was found (CV=7.6%,6.9%;7.0% y 5.4%). According to these results, the %MAP where the physiological events were found seems to be a useful covariable to predict each TTE for training or competing purposes. Finally, in the third part of the work, the results of studies IV y V have been included. The validity of two different methods to estimate the cyclists’ workload at MLSS was evaluated. The first method was a 20 min time trial test (20TT), while the second method was a one-day incremental protocol including 4 steps of 10 minutes (1day_MLSS). The 20TT test absolute reproducibility, performed in duplicate, was very high (CV = -0.3±2.2%, ICC = 0.966, bias = 0.7±6.3 W). 95% of the mean 20TT workload overestimated the MLSS (bias 12.3±6.1W). In contrast, 91% of 20TT showed an accurate prediction of MLSS (bias 1.2±6.1 W), although the regression equation "MLSS (W) = 0.7489 * 20TT (W) + 43.203" showed even a better MLSS estimates (bias 0.1±5.0 W). Related to the 1day_MLSS test, the physiological steady state was determined as the highest workload that could be maintained with a [Lact] rise lower than 1mmol·L-1. No significant differences were detected between the MLSS (247±22 W) and the main construct of the test (DIF_10to10) (245±23 W), where the difference of [Lact] between minute 10 of two consecutive steps were considered, with high correlations (ICC = 0.960), low bias (2.2W), as well as high within-subject reliability (ICC = 0.846, CV = 0.4%, Bias = 2.2±6.4W). Both methods were revealed as valid predictors of the MLSS, significantly reducing the requirements needed to individually determine this specific intensity.
... In addition, we reported for the first time reductions in functional performance, finding ∼1.3 cm less jumping height and ∼0.5 s slower sprinting after 10-week detraining. These results highlight the importance of maintaining RT programmes during transition periods to minimize excessive declines in neuromuscular and functional performance ( García-Pallarés et al., 2010). ...
Article
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The choice of the optimal squatting depth for resistance training (RT) has been a matter of debate for decades and is still controversial. In this study, fifty-three resistance-trained men were randomly assigned to one of four training groups: full squat (F-SQ), parallel squat (P-SQ), half squat (H-SQ), and Control (training cessation). Experimental groups completed a 10-week velocity-based RT programme using the same relative load (linear periodization from 60% to 80% 1RM), only differing in the depth of the squat trained. The individual range of motion and spinal curvatures for each squat variation were determined in the familiarization and subsequently replicated in every lift during the training and testing sessions. Neuromuscular adaptations were evaluated by one-repetition maximum strength (1RM) and mean propulsive velocity (MPV) at each squatting depth. Functional performance was assessed by countermovement jump, 20-m sprint and Wingate tests. Physical functional disability included pain and stiffness records. F-SQ was the only group that increased 1RM and MPV in the three squat variations (ES = 0.77–2.36), and achieved the highest functional performance (ES = 0.35–0.85). P-SQ group obtained the second best results (ES = 0.15–0.56). H-SQ produced no increments in neuromuscular and functional performance (ES = −0.11–0.28) and was the only group reporting significant increases in pain, stiffness and physical functional disability (ES = 1.21–0.87). Controls declined on all tests (ES = 0.02–1.32). We recommend using F-SQ or P-SQ exercises to improve strength and functional performance in well-trained athletes. In turn, the use of H-SQ is inadvisable due to the limited performance improvements and the increments in pain and discomfort after continued training.
... These limitations can cause a negative impact on the mental and physical health of the competitive athlete [10][11][12][13] as many athletes are deprived of access to the needed equipment, facilities, and space to complete training regimens. Those who participate regularly at a high level of exercise and training are especially prone to exhibit negative mental health impacts [14]. ...
... A number of studies with adults have demonstrated that detraining can diminish the training-induced muscular performance enhancements (i.e., strength, muscle activation, and cross-sectional area [CSA]) relatively quickly to baseline values (8). For example, this return to baseline has been reported with 4, 12, and 16 weeks of training with 4-8 weeks of detraining (20,23,28,29), 3 months of training followed by 3 months of detraining (1,2,32). Not all adult detraining studies demonstrate loss of training-induced adaptations. ...
Article
Chaouachi, A, Ben Othman, A, Makhlouf, I, Young, JD, Granacher, U, and Behm, DG. Global training effects of trained and untrained muscles with youth can be maintained during 4 weeks of detraining. J Strength Cond Res 33(10): 2788-2800, 2019-Global (whole-body) effects of resistance training (i.e., cross-education) may be pervasive with children. Detrain-ing induces less substantial deficits with children than adults. It was the objective of this study to investigate the global responses to 4 weeks of detraining after 8 weeks of unilateral leg press (LP) training in 10-13-year-old, pre-peak-height-velocity stage boys. Subjects were randomly separated into 2 unilateral resistance training groups (high load/low repetitions [HL-LR] and low load/high repetitions [LL-HR], and control group). Assessments at pre-training, post-training, and detraining included dominant and nondominant limbs, unilateral , 1 repetition maximum (1RM) and 60% 1RM LP, knee extension, knee flexion, elbow flexion, and handgrip maximal voluntary isometric contraction (MVIC), and countermovement jump (CMJ). All measures significantly increased from pre-test to detraining for both training programs, except for elbow flex-ion MVIC with increases only with HL-LR. All measures except CMJ and handgrip MVIC significantly decreased from post-test to detraining, except for elbow flexion MVIC with decreases only with HL-LR. The dominant trained limb experienced significantly greater LP improvements (pre-to detraining) and dec-rements (post-to detraining) with LP 1RM and 60% 1RM LP. In conclusion, youth HL-LR and LL-HR global training effects of trained and untrained limbs demonstrate similar benefits (pre-to detraining) and decrements (post-to detraining) with detraining. The findings emphasize that training any muscle group in a child can have positive global implications for improved strength and power that can persist over baseline measures for at least a month.
... Tesch, 1983 yılında yaptığı çalışmada kano sporunun bir disiplini olan kayak üzerinde çalışmış ve aerobik güç değerlerini oldukça yüksek bulmakla birlikte; koşu, kürek ve yol bisikletine göre daha düşük değerlerin varlığını saptamıştır (28). Kano sporcuları ile elit kayakçılar üzerinde yapılan birden fazla karşılaştırma çalışmasında; kano sporcuları elit kayakçılardan daha düşük aerobik güç sergilemişlerdir (25,29). Hamano et al. (2), yaş ortalamaları 20.6±0.9 yıl olan kano ve kayak sporcuları üzerinde yaptıkları çalışmada her iki grupta benzer aerobik kapasiteler belirlemişlerdir (sırasıyla 54.3±4.3 ve 55.6±3.7 ml/dk/kg). ...
Article
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Objective: The purpose of this study was to investigate the respiratory function, respiratory muscle strength, postural sway and aerobic capacity parameters of canoeing athletes, and to compare these parameters between sprint and slalom canoeing athletes. Materials and Methods: A total of 34 male canoeing athletes that are composed of 15 sprint and 19 slalom canoeing athletes, with an average age of 20.4±1.6 years, were included in the study. Respiratory function and respiratory muscle strength of the athletes were measured with a digital spirometer, postural sway was measured with the Body Sway Module, and aerobic capacity was measured using a breath-by-breath automatic portable gas analysis system. Independent samples T-test was used to compare the variables obtained from sprint and slalom canoeing athletes. Statistical error level was taken as p<0.05. Results: It was determined that there were no statistically significant differences between the respiratory function, inspiratory and expiratory respiratory muscle strength, postural sway and aerobic capacity parameters of sprint and slalom canoeing athletes (p>0.05). Conclusion: The results obtained from this study reveal that sprint and slalom canoeing athletes have similar respiratory function, respiratory muscle strength, postural sway and aerobic capacity. These results can be used as an initial reference to define training program requirements to increase peripheral muscle strength, respiratory function, respiratory muscle strength, postüral sway, and aerobic capacity in canoeing athletes.
... Prone bench pull (PBP) is an upper body pulling exercise that is commonly used for training the upper back muscles and testing of upper body pulling strength [5]. Studies have investigated the kinematics and kinetics of this exercise [18][19][20], as well as its relation to sports performance [21][22][23]. Although, the study by Uali et al. were required to perform prone bench pull 1 repetition maximum and isometric prone bench pull tests during the familiarization and actual testing sessions. Isometric prone bench pull was performed at 90° and 120° elbow angles. ...
Article
Isometric strength tests are gaining popularity in recent years. However, no study has validated any isometric strength tests to assess upper body pulling ability. The aim of this study was to investigate the validity and reliability of isometric prone bench pull. Twenty-three resistance trained athletes (age: 26±4 years, height: 1.75±0.07 m, body mass: 78.6±11.5 kg) were required to perform prone bench pull 1 repetition maximum and isometric prone bench pull tests during the familiarization and actual testing sessions. Isometric prone bench pull was performed at 90° and 120° elbow angles. Peak force and rate of force development measures were highly reliable with intra-correlation coefficient between 0.881–0.987. Peak force obtained from isometric prone bench pull at both elbow angles showed large correlations to prone bench pull 1 repetition maximum (r=0.833–0.858, p<0.01). Linear regression equations to predict 1RM performance from isometric prone bench pull peak force produced an estimated 1RM with a standard error of only 3–6% of the average prone bench pull 1 repetition maximum. The current findings show that isometric prone bench pull is a reliable test and can be used to predict prone bench pull performance.
... Although some investigations have concluded that neural changes are long-lasting and did not affect the elements of H-reflex pathways [13], there is strong evidence to think the opposite. For example, it was reported that neuromuscular performance was impaired in top-level male kayakers after 5 weeks of either reduced training or complete training cessation [14]. A recent systematic review [15] revealed that the concurrent (CT) training-induced gains may be compromised with a short-term detraining period (2-4 weeks), leading to a return to baseline values. ...
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In December of 2019, there was an outbreak of a severe acute respiratory syndrome caused by the Coronavirus 2 (SARS-CoV-2 or COVID-19) in China. The virus rapidly spread into the whole World causing an unprecedented pandemic and forcing governments to impose a global quarantine, entering an extreme unknown situation. The organizational consequences of quarantine/isolation are: absence of organized training and competition, lack of communication among athletes and coaches, inability to move freely, lack of adequate sunlight exposure, inappropriate training conditions. Based on the current scientific, we strongly recommend encouraging the athlete to reset their mindset to understand quarantine as an opportunity for development, organizing appropriate guidance, educating and encourage athletes to apply appropriate preventive behavior and hygiene measures to promote immunity and ensuring good living isolation conditions. The athlete's living space should be equipped with cardio and resistance training equipment (portable bicycle or rowing ergometer). Some forms of body mass resistance circuit-based training could promote aerobic adaptation. Sports skills training should be organized based on the athlete's needs. Personalized conditioning training should be carried out with emphasis on neuromuscular performance. Athletes should also be educated about nutrition (Vitamin D and proteins) and hydration. Strategies should be developed to control body composition. Mental fatigue should be anticipated and mental controlled. Adequate methods of recovery should be provided. Daily monitoring should be established. This is an ideal situation in which to rethink personal life, understanding the situation, that can be promoted in these difficult times that affect practically the whole world.
... Longer periods without strength training (12 weeks) may lead to reduced strength of 7-12% in strength trained individuals (Mujika and Padilla, 2000). Importantly, small quantities of training can attenuate the strength loss following complete training cessation in high levels athletes (García-Pallarés et al., 2010). Our planned data collection involving female football players was abruptly interrupted by the pandemic. ...
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IntroductionThe COVID-19 outbreak with partial lockdown has inevitably led to an alteration in training routines for football players worldwide. Thus, coaches had to face with the novel challenge of minimizing the potential decline in fitness during this period of training disruption.Methods In this observational pre- to posttest study involving Norwegian female football players (18.8 ± 1.9 years, height 1.68 ± 0.4 m, mass 61.3 ± 3.7 kg), we investigated the effects of a prescribed home-based and group-based intervention, implemented during the COVID-19 lockdown, on maximal muscular force production and high velocity variables. Specifically, maximal partial squat strength one repetition maximum (1RM), counter movement jump (CMJ) and 15 m sprint time were assessed 1 week prior to the lockdown and 12 weeks after the onset of lockdown. We also collected training content and volume from the prescribed training program and self-reported perceived training quality and motivation toward training.ResultsWe observed no change in 1RM [pretest: 104 ± 12 kg, posttest: 101 ± 11 kg (P = 0.28)], CMJ height [pretest: 28.1 ± 2.3 cm, posttest: 26.8 ± 1.9 (P = 0.09)], and 15 m sprint time [pretest: 2.60 ± 0.08 s, posttest: 2.61 ± 0.07 s (P = 0.52)].Conclusion Our findings suggest that a prescribed home-based and group-based intervention with increased training time devoted to strength, jump, and sprint ability, and regulated to obtain a sufficient infection control level is feasible and effective to preserve strength, jumping, and sprinting abilities of high-level female football players during a ∼ 3-month period of a pandemic-induced lockdown.
... 13,14 Moreover, this forced isolation may be characterized as a detraining period, affecting different physiological systems, such as neuromuscular, cardiovascular, respiratory, and their corresponding physical capacities (muscular strength, and power, endurance, flexibility). 15 Previous investigations have reported reductions in neuromuscular performance in just five weeks of training cessation, 16 with some authors pointing out that 2 to 4 weeks are just enough to elicit performance loss. 17 Aerobic performance, for example, may reduce within two to four weeks of detraining in competitive swimmers. ...
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Introduction: The COVID-19 pandemic has led to social isolation measures in different contexts. In endurance sports, competitions worldwide have been canceled, affecting behavioral, psychological, and physical aspects. Objective: This study aimed to assess potential associations between stress, motivation, behavioral changes, and physical fitness in endurance athletes, and time in social isolation. Methods: A cross-sectional study with the participation of 201 athletes, including mountain bikers (n = 89), runners (n = 88) and triathletes (n = 24). Each participant answered questions about time spent in isolation; body weight; changes in training schedule during the isolation period; levels of motivation; stress levels; loss of physical fitness; what aspect of physical fitness was most jeopardized during the isolation period; alcohol consumption; quality of sleep; quality of diet; and whether they had been ill during the isolation period. Results: The results showed significant differences between the percentage of runners (4.5%) and triathletes (16.7%) who had been isolated from 1-10 days, and between the percentage of cyclists (41.6%) and runners (68.2%) in 11-20 days and >20 days (28.1% and 9.1%) respectively. Social isolation was significantly associated with at least one variable for the three groups of athletes; however, the runners were the most affected by the pandemic, presenting an association with low motivation, high stress, poorer quality of sleep, increased alcohol consumption, and loss of physical fitness. Conclusion: Our study showed that the period of social isolation, specifically over time > 10 days, generated significant changes in the perceptions of motivation, stress, alcohol consumption, and physical fitness of endurance athletes, with runners being the most affected group. Level of Evidence III; Diagnostic studies - Investigation of a diagnostic test; Study of non-consecutive patients, without a “gold standard” applied uniformly.
... 42 As muscle power is particularly susceptible to detraining, even in athletes with experience, plyometric training 44 and a maintenance program of resistance training are necessary to avoid excessive declines in neuromuscular function in breaks longer than two or three weeks. 45 The use of inexpensive equipment such as elastic bands or small weights is also an outstanding alternative to the unavailability of bulky traditional strength equipment during the confinement. Bands are affordable, can be used almost everywhere; many exercises can increase their resistance with them and show a similar effect in prime movers, antagonists, synergists, and stabilizing muscles to isoinertial resistance training. ...
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The COVID-19 pandemic has affected many sectors of our global society since its detection in Wuhan in December 2019, and team sports have been no stranger to this reality. This special article presents a review of the literature exposing the dangers for athletes of this virus, reporting the effects of the pandemic on competitive sport, and making evidence-based recommendations to avoid the consequences of detraining in confined athletes. Furthermore, we present the results of a survey with 361 answers computed from coaches and different staff members from 26 different countries, representing the activity of more than 4500 athletes from all over the world. The aim was to know more teams’ activity during this cessation period. Finally, the article outlines recommendations based on the answers to help teams if a second outbreak of the virus forces massive confinements again, guiding a safe return to sport at any competitive level.
... Although this study reports professional cyclists' response to the 7-week COVID-19 lockdown for the first time, our findings support earlier evidence that insufficient training stimulus during more than 5 weeks declined the cardiovascular and functional performance in elite athletes. 12 In contrast, training reductions during 3 weeks seem not to cause severe performance deterioration in well-trained cyclists. 13 While the mechanism explaining these impairments has been previously discussed, 7 new data are provided about the potential effects of training volume and intensity distribution in decreasing cycling performance. ...
Article
Purpose: The COVID-19 outbreak has challenged professional athletes' training and competition routines in a way not seen before. This report aims to inform about the changes in training volume and intensity distribution and their effects on functional performance due to a 7-week home-confinement period in professional road cyclists from a Union Cycliste Internationale Pro Team. Methods: A total of 18 male professional cyclists (mean [SD] age = 24.9 [2.8] y, body mass = 66.5 [5.6] kg, maximal aerobic power = 449 [39] W; 6.8 [0.6] W/kg) were monitored during the 10 weeks before the lockdown (outdoor cycling) and the 7-week lockdown (indoor cycling turbo trainer). Data from the mean maximal power output (in watts per kilogram) produced during the best 5-minute and best 20-minute records and the training intensity distributions (weekly volumes at power-based training zones) were collected from WKO5 software. Results: Total training volume decreased 33.9% during the lockdown (P < .01). Weekly volumes by standardized zones (Z1 to Z6) declined between 25.8% and 52.2% (effect size from 0.83 to 1.57), except for Z2 (P = .38). There were large reductions in best 5-minute and best 20-minute performance (effect size > 1.36; P < .001) with losses between 1% and 19% in all the cyclists. Conclusions: Total indoor volumes of 12 hours per week, with 6 hours per week at low intensity (Z1 and Z2) and 2 hours per week at high intensity over the threshold (Z5 and Z6), were insufficient to maintain performance in elite road cyclists during the COVID-19 lockdown. Such performance declines should be considered to enable a safe and effective return to competition.
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Sánchez-Moreno, M, Cornejo-Daza, PJ, González-Badillo, JJ, and Pareja-Blanco, F. Effects of velocity loss during body mass prone-grip pull-up training on strength and endurance performance. J Strength Cond Res 34(4): 911-917, 2020-This study aimed to analyze the effects of 2 pull-up (PU) training programs that differed in the magnitude of repetition velocity loss allowed in each set (25% velocity loss "VL25" vs. 50% velocity loss "VL50") on PU performance. Twenty-nine strength-trained men (age = 26.1 ± 6.3 years, body mass [BM] = 74.2 ± 6.4 kg, and 15.9 ± 4.9 PU repetitions to failure) were randomly assigned to 2 groups: VL25 (n = 15) or VL50 (n = 14) and followed an 8-week (16 sessions) velocity-based BM prone-grip PU training program. Mean propulsive velocity (MPV) was monitored in all repetitions. Assessments performed at pre-training and post-training included estimated 1 repetition maximum; average MPV attained with all common external loads used during pre-training and post-training testing (AVinc); peak MPV lifting one's own BM (MPVbest); maximum number of repetitions to failure lifting one's own BM (MNR); and average MPV corresponding to the same number of repetitions lifting one's own BM performed during pre-training testing (AVMNR). VL25 attained significantly greater gains than VL50 in all analyzed variables except in MNR (P < 0.05). In addition, VL25 improved significantly (P < 0.001) in all the evaluated variables while VL50 remained unchanged. In conclusion, our results suggest that once a 25% velocity loss is achieved during PU training, further repetitions did not elicit additional gains and can even blunt the improvement in strength and endurance performance.
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A Canoagem slalom é uma modalidade realizada em um curso de água com duração compreendia entre 90 a 120 s e carente de investigações científicas relacionadas ao treinamento e avaliação. Nesse sentido, o objetivo geral do presente projeto foi propor avaliações fisiológicas específicas à canoagem slalom, quantificando e avaliando os efeitos do treinamento monitorado nas condições aeróbia, anaeróbia e na performance desportiva de canoístas de elevado rendimento. Participaram do estudo seis atletas pertencentes à categoria principal de equipe filiada à Confederação Brasileira de Canoagem. Os treinos e as avaliações foram realizados na Lagoa de Piracicaba e no Rio de Piracicaba, mesmos locais onde os avaliados realizaram treinamento específico. Alguns testes foram realizados ao longo de vinte e duas semanas de treinamento monitorado, nos momentos: inicial (M0), após quatorze semanas (M1), após vinte e duas semanas (M2). Os testes adaptados à especificidade da modalidade foram o protocolo progressivo realizado com o intuito de determinar o limiar anaeróbio por concentração de lactato sanguíneo e o modelo de potência crítica, adaptado para estimar a velocidade crítica (VCrit) e capacidade de remada anaeróbia (CRA) de canoístas. Provas simuladas foram realizadas para avaliar a performance (tempo de prova e velocidade média de prova), sendo também analisados parâmetros técnicos referentes às remadas efetuadas e respostas fisiológicas (lactacidemia e freqüência cardíaca). Ao longo do programa de treinamento analisado, a carga de treinamento individual foi obtida ao final de cada sessão, sendo considerada o produto da escala de percepção subjetiva de esforço (PSE) pelo volume da sessão (min). Os resultados serão apresentados na forma de três artigos. O primeiro estudo objetivou caracterizar e testar a reprodutibilidade entre simulações de prova de canoagem slalom, realizadas em dois dias distintos, analisando respostas fisiológicas, técnicas e de performance na modalidade. Elevada intensidade e curta duração foram características da prova simulada, como observado pelas respostas fisiológicas analisadas. Além disso, positivas e significantes correlações entre diversas variáveis foram obtidas, sugerindo que o modelo de simulação é um indicador exeqüível e de grande valia para avaliações na canoagem slalom. O segundo estudo sugeriu um teste específico de limiar anaeróbio para canoagem slalom, comparando os resultados obtidos por esse protocolo aos estimados por método não invasivo de velocidade crítica, e ainda testou a sensibilidade dos parâmetros aeróbios e anaeróbios fornecidos por ambos os testes após sete semanas de treinamento monitorado na modalidade. A partir dos dados encontrados, conclui-se que o protocolo invasivo baseado nas respostas lactacidêmicas e adaptado às especificidades da canoagem slalom foi efetuado com sucesso e apresentou sensibilidade às sete semanas de treinamento para os canoístas, com carga não variada. Por outro lado, a VCrit e CRA foram mantidas após as semanas de treinamento analisadas . Palavras-chave: Avaliações fisiológicas, cargas de treinamento, canoagem slalom, provas simuladas, limiar anaeróbio, velocidade crítica.
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A distance runner's performance is generally limited by energy availability when competing or training. Modifying meal frequency and timing by abstaining from eating or drinking, from dawn to dusk, during Ramadan fasting is hypothesized to induce hypohydration and reduced caloric and nutrient intake. The purpose of this study was to investigate the impact of Ramadan fasting on runners' performances. Fifteen trained male distance runners who observed Ramadan participated in this study (Age = 23.9 ± 3.1 years; Peak VO 2 = 71.1 ± 3.4 ml/kg/min). Each participant reported to the human performance lab on two testing occasions (pre-Ramadan and the last week of Ramadan). In each visit, participants performed a graded exercise test on the treadmill (Conconi protocol) and their VO 2 , Heart Rate, time to exhaustion, RPE, and running speed were recorded. Detailed anthropometrics, food records, and exercise logs were kept for the entire period of the study. Repeated measure ANOVA, paired t -test, and Cohen's effect size analysis were carried out. Results indicated no significant influence for Ramadan fasting on body mass ( p = 0.201), body fat ( p = 0.488), lean body mass ( p = 0.525), VO 2 max ( p = 0.960), energy availability ( p = 0.137), and protein intake ( p = 0.124). However, carbohydrate ( p = 0.026), lipid ( p = 0.009), water ( p < 0.001), and caloric intakes ( p = 0.002) were significantly reduced during Ramadan Fasting. Daily training duration ( p < 0.001) and exercise energy expenditure ( p = 0.001) were also reduced after Ramadan. Time to exhaustion ( p = 0.049), and maximal running speed ( p = 0.048) were improved. Overall, time to exhaustion and maximal running speed of the distance runners was improved during Ramadan fasting, independent of changes in nutrients intake observed during the current study. With proper modulation of training, distance runners performance can be maintained or even slightly improved following the month of Ramadan fasting.
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Purpose: to analyze the relationship between movement velocity and relative load (%1RM) in the pull-up exercise (PU), and to determine the pattern of repetition velocity loss during a single set to failure in pulling one's own body mass. Methods: Fifty-two men (age = 26.5 ± 3.9 years, body mass = 74.3 ± 7.2 kg) performed a first evaluation (T1) consisting of an one-repetition maximum test (1RM), and a test of maximum number of repetitions to failure pulling one's own body mass (MNR) in the PU exercise. Thirty-nine subjects performed both tests on a second occasion (T2) following 12 weeks' training. Results: We observed a strong relationship between mean propulsive velocity (MPV) and %1RM (r = -.96). Mean velocity attained with 1RM load (V1RM) was 0.20 ± 0.05 m·s(-1) and it influenced the MPV attained with each %1RM. Although 1RM increased by 3.4% from T1 to T2, the relationship between MPV and %1RM, and V1RM remained stable. We also confirmed stability in the V1RM regardless of individual relative strength. We found a strong relationship between percentage of velocity loss and percentage of performed repetitions (R(2) = .88), which remained stable despite a 15% increase in MNR. Conclusions: Monitoring repetition velocity allows estimation of the %1RM used as soon as the first repetition with a given load is performed, and the number of repetitions remaining in reserve when a given percentage of velocity loss is achieved during a PU exercise set.
Article
There was an outbreak of severe acute respiratory syndrome by SARS-CoV-2 or COVID-19 in China. The virus spread quickly throughout the world, including in Indonesia. The government has taken many steps to reduce the spread of COVID-19, namely the Stay at Home phase, the Large-Scale Social Restrictions phase, and the New Normal phase. The entire process has affected sports by imposing Training from Home (TFH) for 14 national male athletes and 11 female national athletes for rowing in preparation for the Asia Cup. The athletes' seriousness in exercising for seven weeks was shown from recorded data during the New Normal. The purpose of this research is to see the effect of TFH on athlete detraining. The absence of specific research related to this is a novelty in this study. The method used is quasi-experimental, by looking at the athletes' seriousness in doing the exercises independently without direct assistance from the coach. The coaches could only assist online. The instrument used met the standards of validity and reliability of conformity. It was expected that the athletes' performance did not decrease as they entered the next stage of training. The results showed no significant effect of TFH on detraining in the components of Muscle Power, Aerobic Power, Capacity Squat, Deadlift, and Bench Pull in the men's group. In the women's group, there was a significant effect of TFH on detraining in Muscle Power and Women's Aerobic Capacity, and there was an insignificant effect of TFH on detraining in the components of Aerobic Power, Squat, Deadlift, and Bench Pull. This study concludes that TFH has different effects on detraining elite rowing athletes during the COVID-19 pandemic.
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Purpose: To describe the acute and delayed time course of recovery following resistance training (RT) protocols differing in the number of repetitions (R) performed in each set (S) out of the maximum possible number (P). Methods: Ten resistance-trained men undertook three RT protocols [S × R(P)]: (1) 3 × 5(10), (2) 6 × 5(10), and (3) 3 × 10(10) in the bench press (BP) and full squat (SQ) exercises. Selected mechanical and biochemical variables were assessed at seven time points (from - 12 h to + 72 h post-exercise). Countermovement jump height (CMJ) and movement velocity against the load that elicited a 1 m s(-1) mean propulsive velocity (V1) and 75% 1RM in the BP and SQ were used as mechanical indicators of neuromuscular performance. Results: Training to muscle failure in each set [3 × 10(10)], even when compared to completing the same total exercise volume [6 × 5(10)], resulted in a significantly higher acute decline of CMJ and velocity against the V1 and 75% 1RM loads in both BP and SQ. In contrast, recovery from the 3 × 5(10) and 6 × 5(10) protocols was significantly faster between 24 and 48 h post-exercise compared to 3 × 10(10). Markers of acute (ammonia, growth hormone) and delayed (creatine kinase) fatigue showed a markedly different course of recovery between protocols, suggesting that training to failure slows down recovery up to 24-48 h post-exercise. Conclusions: RT leading to failure considerably increases the time needed for the recovery of neuromuscular function and metabolic and hormonal homeostasis. Avoiding failure would allow athletes to be in a better neuromuscular condition to undertake a new training session or competition in a shorter period of time.
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The COVID-19 pandemic and the forced home confinement have risen a new challenge in the field of sport and exercise sciences, which consists in how to limit and counteract detraining-induced effects among athletes. Despite training cessation has been linked to a multitude of detrimental effects on human health and physical performance, very little is known about how these effects can be prevented. By drawing on discoveries in training reduction and cessation studies, here we illustrate the potential morphological, physiological and functional changes induced by home-confinement. Specific issues associated with the case of injured athletes have also been discussed. This brief report is also expected to provide useful implications for individuals who have to live and face situations of isolation and confinement in extreme environments.
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Introduction: Adaptation to attitude is a complementary exercise to increase athletes' fitness and physiological performance. The present study investigated the effect of high intensity interval training at the hypobaric hypoxia conditions on weight changes and endurance performance test in rats following a three-weeks tapering period. Materials and Methods: In this experimental study, 25 males four weeks age Wistar rats with average weight (81±9 g) were randomly divided in two groups, exercise and control. Exercise group after the end of 6 weeks high intensity interval training (HIIT) (5 days per week, 30 minutes per session and at a speed of 15 to 70 meters per minute) divided into HIIT, Hypoxia, Taper and hypoxia with taper groups for 3 weeks. Weight changes and Endurance Test Performance were evaluated on the end of weeks. Analyzed is done with one-way ANOVA and TUKEY test at p<0.05. Results: The results showed that there are significant differences (p≤0.05) in fatigue times in hypoxic and taper-hypoxia groups with interval training group, respectively, 30.59 and 37.08. (p=0.001). Also, taper-hypoxic group showed the best performance to compare HIIT and control groups, that was increase significantly (p=0.001). Conclusion: It seems that use of hypoxic training program and taper techniques have a positive effect on endurance performance and time to exhaustion however the use taper with hypoxia condition need to be evaluated in combination.
Article
p>El objetivo de esta investigación es validar nuevas ecuaciones de regresión para estimar el valor de fuerza dinámica máxima absoluta (1RM) mediante test de máximo número de repeticiones hasta el fallo muscular (nRM) ejecutados con técnica de parada o stop. Igualmente, se estudian los niveles de validez que presentan las ecuaciones que ya se encuentran actualmente definidas en la literatura internacional para estimar la magnitud de la carga (%1RM) y el valor de 1RM a partir de un test nRM en ejecuciones con técnica de parada. Los resultados indican que las nuevas ecuaciones propuestas en esta investigación [1RM en Press Banca = masa desplazada en kg (-0,01841*nRM)+0,981; 1RM en Sentadilla Completa = masa desplazada en kg (-0,01176*nRM)+0,975] muestran indicadores sustancialmente mejores de validez(ET = 1,8-2,2 kg; R<sup>2</sup> = 0,956-0,988), y por lo tanto de mayor capacidad predictiva, que el resto de ecuaciones definidas en la literatura internacional hasta la fecha.</p
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Background and Aim: Detraining could causes changes in blood lactate response and physical fitness factors. Therefore the aim of this study was to investigate the effect of three-weeks of detraining on blood lactate response to kick exercise and physical fitness factors related to Taekwondo in teenage girls. Materials and Methods: Eigtheen taekwondo athlete girls with mean age of 13±1.64 years and taekwondo experience period with 6.07±1.05 years were randomly divided into training (n=9) and detraining (n=9) groups. Dependent variables were measured before and after three weeks in both groups. Detraining groups stopped their training program during the three weeks but training group continued their training program. Blood lactate was measured before and immediately after kick exercise; in this way, after 20 minutes of warm-up, kick exercise (short time, high-intensity exercise) were performed with 3 repetitions, each repetition was included 20 seconds of activity and 20 seconds of recovery. Anaerobic power, agility, muscular power and reaction time were evaluated with valid tests. Repeated measure ANOVA and MANCOVA tests were used for statistical analysis of inter group and between groups changes respectively and significant level was considered if P>0.05. Results: Blood lactate after kick exercise was increased significantly in both groups pre and post 3 weeks (p=0.001), but it was not significantly differ before and after intended three weeks (p=1.00). In detraining group, muscular power (p=0.01), agility (p=0.04) and anaerobic power (p=0.01) decreased significantly after three weeks of detracting as compared to before three weeks detraining but reaction time did not significantly change (p=0.17). Conclusion: It seems that three weeks of detraining in Taekwondo girls does not induce any changes in lactate response to kick exercise and their reaction time but it decreases the other skill related physical fitness factors.
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تداعيات الحجر الصحي على التكيفات التي اكتسبها الرياضيين خلال المراحل التدريبة السابقة لفترة الحجر الصحي والخطط الكفيلة بمواجهتها
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Krespi, M, Sporiˇ s, G, and Trajkovi ´ c, N. Effects of two different tapering protocols on fitness and physical match performance in elite junior soccer players. J Strength Cond Res XX(X): 000–000, 2018—The purpose of this study was to determine the effects of 2 different tapering protocols on fitness and physical match performance in elite junior soccer players. One-hundred fifty-eight elite junior soccer players (mean age: 17.1 6 0.79 years; mean height: 177.9 6 6.64 cm; mean body mass: 71.3 6 7.96 kg; and mean body mass index: 22.5 6 1.66 kg$m22) were randomly assigned to 2 groups: an exponential (n = 79) and a linear tapering (n = 79) group. Training sessions were conducted 3 times per week for 8 weeks. After 4 weeks of training and 4 weeks of tapering, participants were assessed in terms of body composition, physical fitness, and distance covered within a match. Both groups showed similar changes for body composition. The exponential group showed better improvement than the linear group in the 5- and 30-m sprints, countermovement jump, and V_ O2max (p , 0.05). The exponential tapering group had larger changes (p , 0.05) than the linear group in medium running (8–13 km$h21) (6%; effect size = 0.26 compared with 5.5%; effect size = 0.22) and sprinting (.18 km$h21) (26%; effect size = 0.72 compared to 21.7%; effect size = 0.60). The results show that exponential tapering produced better effects on speed, power, and endurance abilities than the linear protocol. Our results confirmed the reports of others that suggest that volume is the optimal variable to manipulate while maintaining both the intensity and the frequency of sessions.
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El objetivo de este trabajo es profundizar en una línea de investigación emergente en el contexto de la psicología del deporte como es el optimismo. A través de la teoría de los estilos explicativos y las dimensiones de permanencia, amplitud y personalización, se llega a dos trabajos específicos que relacionan por un lado el optimismo con el rendimiento y por otro la posible influencia de los estilos explicativos del entrenador en el análisis de la competición sobre los jugadores de un equipo. A partir de los resultados de ambos trabajos se establece la reflexión sobre la importancia del constructo optimismo en todos los aspectos de la competición deportiva así las posibilidades de modificar los estilos explicativos y trabajar en este sentido desde la disciplina de la psicología del deporte.
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Background: Recently, there have been rising demands on the specifics of functional load testing, which should with its motor structure correspond or at least draw near the sport specialization. However, evaluation of specific forms of diagnostics is very pure in canoe slalom. Objective: The aim of the study was to compare a physiological response based on results in graded functional test when paddling in a single canoe (C1) and results reached in the standardized arm crank ergometrics. Methods: The research sample consisted of 6 elite Czech single canoeists, members of Czech senior national team and the Czech national team up to 23 years. Their average weight was 79.7±6.6 kg, height 183.4±6.6 cm and age 23.6±3.9 years.Results: When comparing the result values of physiological indicators measured in both functional tests, we have found out significant differences (statistical and substantive) in variables: VO2peak (p=0.00; 15.1%), VEpeak (p=0.06, 11.1%), HR (p=0.02; 5.7%), RR (p=0.18; 9.3%), VT (p=0.00; 18.8%) and RER (p=0.26; 4.0%). With the exception of respiratory rate, significantly lower values of all physiological variables were found in on-water testing (C1). Although there was a strong correlation between the VO2peak indicators (r=0.79, p=0.06) found between paddling and crank ergometrics, this relationship cannot be considered significant (p=0.06) due to the small research sample. Conclusions: To evaluate on-water testing and to determine the external validity of arm crank ergometrics for C1 diagnostics, it is necessary to test a bigger research sample. Therefore, it is a pilot study. However, the results indicate that the physiological load requirements in the C1 category are different from those of the kayak category (K1). Although C1 paddlers reached similar VO2peak values in the arm crank ergometrics as kayakers, in the on-water test they reached about 10 ml.kg.min-1 lower oxygen uptake compared to kayakers (Busta, Bílý, Suchý, & Kovářová, 2017).
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Purpose: To test whether the force-velocity (F-V) relationship obtained during a specific single-stroke kayak test (SSKT) and during nonspecific traditional resistance-training exercises (bench press and prone bench pull) could discriminate between 200-m specialists and longer-distance (500- and 1000-m) specialists in canoe sprint. Methods: A total of 21 experienced male kayakers (seven 200-m specialists and 14 longer-distance specialists) participated in this study. After a familiarization session, kayakers came to the laboratory on 2 occasions separated by 48 to 96 hours. In a randomized order, kayakers performed the SSKT in one session and the bench press and bench pull tests in another session. Force and velocity outputs were recorded against 5 loads in each exercise to determine the F-V relationship and related parameters (maximum force, maximum velocity, F-V slope, and maximum power). Results: The individual F-V relationships were highly linear for the SSKT (r = .990 [.908, .998]), bench press (r = .993 [.974, .999]), and prone bench pull (r = .998 [.992, 1.000]). The F-V relationship parameters (maximum force, maximum velocity, and maximum power) were significantly higher for 200-m specialists compared with longer-distance specialists (all Ps ≤ .047) with large effect sizes (≥0.94) revealing important practical differences. However, no significant differences were observed between 200-m specialists and longer-distance specialists in the F-V slope (P ≥ .477). Conclusions: The F-V relationship assessed during both specific (SSKT) and nonspecific upper-body tasks (bench press and bench pull) may distinguish between kayakers specialized in different distances.
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Th e purpose of the present study was to investigate the eff ects of exponential and linear tapering protocols on the distance covered according to playing positions among junior elite soccer players. One-hundred and fi ft y-eight junior elite soccer players (mean age: 17.07±0.79 years; mean height: 177.85±6.64 cm; mean weight: 71.27±7.96 kg; mean body-mass index: 22.50±1.66 kg/m²) were randomly selected into two groups: (1) exponential and (2) linear tapering group. Training sessions were conducted three times a week for eight weeks. Aft er four and eight weeks of the tapering period, participants were measured in the distance covered according to four basic playing positions on the fi eld: (1) goalkeepers, (2) defenders, (3) midfi elders, and (4) forwards. Th e results showed that the largest eff ects between the pre- and post-measurement had defenders in the exponential and goalkeepers in the linear group, goalkeepers in the distance covered by slow and medium running in both groups, forwards in fast running and sprinting in the exponential group, and midfi elders in the linear group. In conclusion, our results suggest that the exponential tapering protocol brought somewhat larger eff ects, especially in fast running and sprinting in forwards and slow and medium running in goalkeepers. Future studies need to implement both the exponential and the linear tapering protocols in order to enhance performance but favouring the exponential to produce larger eff ects.
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1 Finland HÄKKINEN K., KOMI P.V. & TESCH P.A. Effect of ccmbined concentric ard eccentric strength training and detraining on force-time, muscle fiber-and metabolic characteristics of leg extensor muscles. Scand. J ,Sports Sci. 3 (2): 50-58, 1981. Prog¡essive strength training of combined concentric and eccentric contractions were performed three times a week for 16 weeks by 14 males {20-30 yrs of age) accustomed to weight training. The training peeriod was iollowed bv 8 weeks of detraining. The training program consisted mainly of dynamic exeicises for the ieg-extensovs with loads of 80 to 120 of one maximum repetition The training caused significant improvements in-maximal force (p < 0.001) and various force-time (p (0.05-4.01) para¡àeters. Du¡ing thg I'ast trarning àionìh tbe inãrease in force was gireatly tri¡nited' and there was ¿ decrease in th,e force-time parameters. The marked improvements in mwcle strength were accompanied by ccnsiderable intemål qdaptatioos ,Ín-ttre tnaCned muscle, as Judged from l¡rcreases (p < 0-001) ,iqr. the fibet ãeas ôt tËe Ïast fi¡¡itch (FT) and slow twitch (ST) fibers. Durlng early conditioning improvement i! the qqgs! jump w,as related to tl.e relãtive hypertrop]ty of tr1l ii¡eis fo <0.01). No sier¡j-Êi,cå,r¡t ct¡anges ,in tJre er¡zyme aittv¡tiês oi mÍoki¡¡ase-a¡¡d creatine kirmse were found as a result of-tra¡rrir}g, but i,ndividt¡al charrges in my-o-kinase activity $/ere related to the relative. hypertrop'hy of FT fibers-(p ç 0.05) and Improvernent i+ the squat jump (p < O.Of)-during early conditiontuag. All the ada,p-iatlo:ns'-incilcating musõle hypertrophy occurred. prtm@lv during the last two training mo¡rths. Decreases (p (0.001) in maxirnal force during the detrairring were accompâ-nied bv a sisrificår¡t rediuction in the fi¡b,er areas of ttle fC tp < 0.01) and ST (p < 0.05) tvpes end by a change in bödy-antliropometry.-A periodiè-and partial usage. of àccentr-ic contráctions,-together with conèentric training' is suggested to be effectiùe in training for-maximal force and äso for force-time eharacteristics. In training of longer durations the specific effects of strength trainlng are-obviot¡s and explaiñable by adaptatlons in the trained muscle. Keg tenns: erìzJûne actlvities, muscle mechanics, muscle metabollsn, muscle streng:th.
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Previous studies show that cessation of resistance training, commonly known as "detraining," is associated with strength loss, decreased neural drive, and muscular atrophy. Detraining may also increase the expression of fast muscle myosin heavy chain (MHC) isoforms. The present study examined the effect of detraining subsequent to resistance training on contractile performance during slow-to-medium velocity isokinetic muscle contraction vs. performance of maximal velocity "unloaded" limb movement (i.e., no external loading of the limb). Maximal knee extensor strength was measured in an isokinetic dynamometer at 30 and 240 degrees/s, and performance of maximal velocity limb movement was measured with a goniometer during maximal unloaded knee extension. Muscle cross-sectional area was determined with MRI. Electromyographic signals were measured in the quadriceps and hamstring muscles. Twitch contractions were evoked in the passive vastus lateralis muscle. MHC isoform composition was determined with SDS-PAGE. Isokinetic muscle strength increased 18% (P < 0.01) and 10% (P < 0.05) at slow and medium velocities, respectively, along with gains in muscle cross-sectional area and increased electromyogram in response to 3 mo of resistance training. After 3 mo of detraining these gains were lost, whereas in contrast maximal unloaded knee extension velocity and power increased 14% (P < 0.05) and 44% (P < 0.05), respectively. Additionally, faster muscle twitch contractile properties along with an increased and decreased amount of MHC type II and MHC type I isoforms, respectively, were observed. In conclusion, detraining subsequent to resistance training increases maximal unloaded movement speed and power in previously untrained subjects. A phenotypic shift toward faster muscle MHC isoforms (I --> IIA --> IIX) and faster electrically evoked muscle contractile properties in response to detraining may explain the present results.
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Previous research on overtraining due to excessive use of maximal resistance exercise loads [100% 1 repetition maximum (1 RM)] indicates that peripheral muscle maladaptation contributes to overtraining-induced performance decrements. This study examined the cellular and molecular responses of skeletal muscle to performance decrements due to high-relative-intensity (%1 RM) resistance exercise overtraining. Weight-trained men were divided into overtrained (OT, n = 8) and control (Con, n = 8) groups. The OT group performed 10 x 1 at 100% 1 RM daily for 2 wk, whereas the Con group performed normal training 2 days/wk. Muscle biopsies from the vastus lateralis muscle, voluntary static and dynamic muscle performances, and nocturnal urinary epinephrine were assessed before (pre) and after (post) overtraining. Overtraining occurred as indicated by a decrease in 1-RM strength for the OT group (mean +/- SE; OT pre = 159.3 +/- 10.1 kg, OT post = 151.4 +/- 9.9 kg, Con pre = 146.0 +/- 12.9 kg, Con post = 144.9 +/- 13.3 kg), as well as a 36.3% decrease in mean power at 100% 1-RM loads. Normal training could be resumed only after 2-8 wk of training cessation. Muscle beta(2)-adrenergic receptor (beta(2)-AR; fmol/mg protein) density significantly decreased by 37.0% for the OT group and was unchanged for the Con group (-1.8%). Nocturnal urinary epinephrine for the OT group increased by 49%, although this was not significant (effect size = 0.42). The ratio of nocturnal urinary epinephrine to beta(2)-AR density suggested a decreased beta(2)-AR sensitivity for the OT group (2.4-fold increase). Overtraining occurred based on decreased muscular force and power. Desensitization of the beta(2)-AR system suggests that this may be an important contributor to performance decrements due to excessive use of maximal resistance exercise loads.
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This study was undertaken to analyze changes in selected cardiovascular and neuromuscular variables in a group of elite kayakers across a 12-week periodized cycle of combined strength and endurance training. Eleven world-class level paddlers underwent a battery of tests and were assessed four times during the training cycle (T0, T1, T2, and T3). On each occasion subjects completed an incremental test to exhaustion on the kayak-ergometer to determine maximal oxygen uptake (VO2max), second ventilatory threshold (VT2), peak blood lactate, paddling speed at VO2max (PSmax) and at VT2 (PSVT2), stroke rate at VO2max and at VT2, heart rate at VO2max and at VT2. One-repetition maximum (1RM) and mean velocity with 45% 1RM load (V 45%) were assessed in the bench press (BP) and prone bench pull (PBP) exercises. Anthropometric measurements (skinfold thicknesses and muscle girths) were also obtained. Training volume and exercise intensity were quantified for each of three training phases (P1, P2, and P3). Significant improvements in VO2max (9.5%), VO2 at VT2 (9.4%), PSmax (6.2%), PSVT2 (4.4%), 1RM in BP (4.2%) and PBP (5.3%), V 45% in BP (14.4%) and PBP (10.0%) were observed from T0 to T3. A 12-week periodized strength and endurance program with special emphasis on prioritizing the sequential development of specific physical fitness components in each training phase (i.e. muscle hypertrophy and VT2 in P1, and maximal strength and aerobic power in P2) seems effective for improving both cardiovascular and neuromuscular markers of highly trained top-level athletes.
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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)
To elucidate the changes in neuro-muscular function during strength training and detraining, five male subjects underwent progressive isotonic strength training of their calf muscles three times a week for 8 weeks with additional detraining for the same periods. Electrically evoked twitch contractions were induced in the triceps surae muscles of each subject every 4 weeks during the training and detraining periods. At the same time, maximal voluntary isometric contractions (MVC) and the maximal girth of the calf (MGC) were measured. During the training period, MVC increased significantly from 98.4 to 129.6 Nm (31.7%, P less than 0.01) for the first 4 weeks of training but MGC showed little increase. Neither of the changes correlated with each other. Twitch contraction parameters, i.e. maximal twitch torque (Pt), maximal rate of torque development (max dT/dt) and rate of relaxation (relax dT/dt) showed no statistical change. During detraining, on the contrary, a large and significant increase (22.5%, P less than 0.01) was observed in max dT/dt without any changes in Pt and relax dT/dt. The MVC/Pt showed both significant increases during training and decreases during detraining. Our data suggest that short term strength training as employed in the present study does not induce changes in the contractile properties of the muscle during training, but may significantly affect the rate of force development during the subsequent detraining period, indicating the possible existence of complex post-training muscle adaptation.
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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.
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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.
Article
Fourteen male subjects (20-30 yr) accustomed to weight training went through progressive strength training of combined concentric and eccentric contractions three times per week for 16 wk. The training was followed by the 8-wk detraining period. The training program consisted mainly of dynamic exercises for leg extensors with the loads of 80-120% of one maximum concentric repetition. Significant improvements in muscle function were observed in early conditioning; however, the increase in maximal force during the very late training period was greatly limited. Marked improvements (P less than 0.001) in muscle strength were accompanied by significant (P less than 0.01) increases in the neural activation (IEMG) of the leg extensor muscles. The relationship between IEMG and high absolute forces changed (P less than 0.01) during the training period. The occurrence of these changes varied during the course of training. It was concluded that the early change in strength may be accounted for largely by neural factors with a gradually increasing contribution of hypertrophic factors as the training proceeds. It was suggested that the magnitudes and occurrence of these changes may vary due to the differences in conditioning periods, in individual muscles of muscle groups, in subject material, and in conditioning methods. During detraining, the decrease in muscle force seemed to be explainable also by the neural and muscular adaptations caused by the inactivity.
To investigate biochemical, histochemical and contractile properties associated with strength training and detraining, six adult males were studied during and after 10 weeks of dynamic strength training for the quadriceps muscle group of one leg, as well as during and after a subsequent 12 weeks of detraining. Peak torque outputs at the velocities tested (0-270 degrees X s-1) were increased (p less than 0.05) by 39-60% and 12-37% after training for the trained and untrained legs, respectively. No significant changes in peak torques were observed in six control subjects tested at the same times. Significant decreases in strength performance of the trained leg (16-21%) and untrained leg (10-15%) were observed only after 12 weeks of detraining. Training resulted in an increase (p less than 0.05) in the area of FTa (21%) and FTb (18%) fibres, while detraining was associated with a 12% decrease in FTb fibre cross-sectional area. However, fibre area changes were only noted in the trained leg. Neither training nor detaining had any significant effect on the specific activity of magnesium-activated myofibrillar ATPase or on the activities of enzymes of phosphagen, glycolytic or oxidative metabolism in serial muscle biopsy samples from both legs. In the absence of any changes in muscle enzyme activities and with only modest changes in FT fibre areas in the trained leg, the significant alterations in peak torque outputs with both legs suggest that neural adaptations play a prominent role in strength performance with training and detraining.
Article
The optimum pre-competition taper procedure for "strength athletes" is not known. We examined voluntary strength and evoked contractile properties of the elbow flexors over a 10 day rest only (ROT) and a 10 day reduced volume taper (RVT) in 8 resistance trained males (23 +/- 2.1 years). Following 3 wks of standardized training of the elbow flexors, subjects were randomly assigned to one of the tapers. Upon completion, they resumed training for 3 wks and completed the other taper. No arm training was performed during the ROT, while high intensity, low volume training was done every second day during the RVT. Maximum isometric (MVC), low (0.52 rad.s-1; LV) and high velocity (3.14 rad.s-1; HV) concentric peak torque, and evoked isometric twitch contractile properties were measured before and after each training phase and every 48 h during each taper. ANOVA comparison of the tapers revealed that MVC increased (p < or = 0.05) over pre-taper values throughout the RVT (measurement days 2, 4, 6, 8 and 10), as did LV at 2, 4, 6, and 8 d. MVC did not change over the ROT but LV was significantly higher on day 2 and lower on days 8 and 10. LV was also greater on days 4, 6, 8 and 10 during the RVT compared to the ROT. The evoked contractile properties remained largely unchanged. The data indicate that resistance-trained athletes can improve low velocity concentric strength for at least 8 days by greatly reducing training volume, but maintaining training intensity.
Article
We investigated the effects of 14 d of resistive exercise detraining on 12 power athletes. In comparing performances pre- to post-detraining, there were no significant (P > 0.05) changes in free weight bench press (-1.7%), parallel squat (-0.9%), isometric (-7%) and isokinetic concentric knee extension force (-2.3%), and vertical jumping (1.2%). In contrast, isokinetic eccentric knee extension force decreased in every subject (-12%, P < 0.05). Post-detraining, the changes in surface EMG activity of the vastus lateralis during isometric, and isokinetic eccentric and concentric knee extension were -8.4%, -10.1%, and -12.7%, respectively (all P > 0.05). No significant changes occurred in knee flexion forces or EMGs (P > 0.05). Percentages of muscle fiber types and the Type I fiber area remained unchanged, but Type II fiber area decreased significantly by -6.4% (P < 0.05). Levels of plasma growth hormone (58.3%), testosterone (19.2%), and the testosterone to cortisol ratio (67.6%) increased, whereas plasma cortisol (-21.5%) and creatine kinase enzyme levels (-82.3%) decreased (all P < 0.05). Short-term resistive exercise detraining may thus specifically affect eccentric strength or the size of the Type II muscle fibers, leaving other aspects of neuromuscular performance uninfluenced. Changes in the hormonal milieu during detraining may be conducive to an enhanced anabolic process, but such changes may not materialize at the tissue level in the absence of the overload training stimulus.
Article
The purpose of this study was to determine whether short-term training cessation resulted in reduced GLUT-4 protein levels. Endurance- (n = 12, ET) and strength-trained (n = 12) individuals (ST) were examined before and after 14 days of training withdrawal. GLUT-4 content was determined from muscle biopsy samples of the gastrocnemius in ET and the vastus lateralis in ST. Insulin sensitivity (oral glucose tolerance test) was significantly (P < 0.05) reduced in ET and ST with training cessation. GLUT-4 content was unaltered (P > 0.05) in both groups (92 and 100% of trained values for ET and ST, respectively). In ET, citrate synthase activity decreased significantly (P < 0.05) with training withdrawal (41.0 +/- 3.6 vs. 30.6 +/- 2.8 mumol.g-1.min-1); in ST no change was evident. The decrement in insulin sensitivity with the cessation of endurance- or resistance-oriented activity is therefore not associated with a reduction in GLUT-4 protein content. Muscle oxidative capacity and GLUT-4 content do not coincide with the removal of endurance training.
The 100-m and 400-m swim time, tethered swimming forces, mood states and self-ratings of well-being of 27 competitive swimmers were measured before and after 4 weeks of intense training and after 1 week and 2 weeks of tapering for major competition. The swimmers were divided into three groups. Each group completed one of three taper regimes similar to those currently performed by swimmers in preparation for competition: (a) reduced training frequency according to each athlete's daily ratings of well-being, (b) reduced training volume, and (c) reduced training volume and intensity. Significant improvements in the Profile of Mood States measures of tension, depression and anger (P < 0.05) were observed after 1 week of tapering, with significant improvements in total mood disturbance and fatigue (P < 0.05) and peak tethered swimming force (P < 0.01) after 2 weeks. Non-significant improvements in 100-m and 400-m swim time (P > 0.05) were observed and no significant differences were revealed among the three tapering techniques. These data highlighted the importance of providing sufficient recovery before competition, since 1 week of reduced training was not long enough to maximise the benefits of tapering. However, none of the three types of tapering currently used by competitive swimmers could be shown to be more beneficial than the others.
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Detraining is the partial or complete loss of training-induced adaptations, in response to an insufficient training stimulus. Detraining characteristics may be different depending on the duration of training cessation or insufficient training. Short term detraining (less than 4 weeks of insufficient training stimulus) is analysed in part I of this review, whereas part II will deal with long term detraining (more than 4 weeks of insufficient training stimulus). Short term cardiorespiratory detraining is characterised in highly trained athletes by a rapid decline in maximal oxygen uptake (VO2max) and blood volume. Exercise heart rate increases insufficiently to counterbalance the decreased stroke volume, and maximal cardiac output is thus reduced. Ventilatory efficiency and endurance performance are also impaired. These changes are more moderate in recently trained individuals. From a metabolic viewpoint, short term inactivity implies an increased reliance on carbohydrate metabolism during exercise, as shown by a higher exercise respiratory exchange ratio, and lowered lipase activity, GLUT-4 content, glycogen level and lactate threshold. At the muscle level, capillary density and oxidative enzyme activities are reduced. Training-induced changes in fibre cross-sectional area are reversed, but strength performance declines are limited. Hormonal changes include a reduced insulin sensitivity, a possible increase in testosterone and growth hormone levels in strength athletes, and a reversal of short term training-induced adaptations in fluid-electrolyte regulating hormones.
Article
This part II discusses detraining following an insufficient training stimulus period longer than 4 weeks, as well as several strategies that may be useful to avoid its negative impact. The maximal oxygen uptake (VO2max) of athletes declines markedly but remains above control values during long term detraining, whereas recently acquired VO2max gains are completely lost. This is partly due to reduced blood volume, cardiac dimensions and ventilatory efficiency, resulting in lower stroke volume and cardiac output, despite increased heart rates. Endurance performance is accordingly impaired. Resting muscle glycogen levels return to baseline, carbohydrate utilisation increases and the lactate threshold is lowered, although it remains above untrained values in the highly trained. At the muscle level, capillarisation, arterial-venous oxygen difference and oxidative enzyme activities decline in athletes and are completely reversed in recently trained individuals, contributing significantly to the long term loss in VO2max. Oxidative fibre proportion is decreased in endurance athletes, whereas it increases in strength athletes, whose fibre areas are significantly reduced. Force production declines slowly, and usually remains above control values for very long periods. All these negative effects can be avoided or limited by reduced training strategies, as long as training intensity is maintained and frequency reduced only moderately. On the other hand, training volume can be markedly reduced. Cross-training may also be effective in maintaining training-induced adaptations. Athletes should use similar-mode exercise, but moderately trained individuals could also benefit from dissimilar-mode cross-training. Finally, the existence of a cross-transfer effect between ipsilateral and contralateral limbs should be considered in order to limit detraining during periods of unilateral immobilisation.
Article
To examine the changes in whole muscle function and single cell contractile properties of Type I and II muscle fibers from the deltoid muscle of highly trained swimmers before and after a 21-d reduction in training volume (taper). Six college male swimmers (age, 20+/-1 yr; height, 187+/-2 cm, weight, 79+/-3 kg, fat, 7+/-1%) who had been, on average, swimming 6200 m x d(-1) for 5 months before the taper participated in this investigation. Whole muscle power increased (P < 0.05) 17% and 13% on the swim bench and swim power tests, respectively. Swim times improved by 4% (range: 3.0-4.7%; P < 0.05). There was no change in Type I fiber diameter, whereas Type IIa fibers were 11% larger (P < 0.05) after taper. Peak force (Po) of the Type I fibers was unaffected by the taper but increased (P < 0.05) from 0.63+/-0.02 to 0.82+/-0.05 mN in the IIa fibers. However, the specific force (Po/CSA) of the IIa fibers was unchanged. Shortening velocity (Vo) was 32% and 67% faster (P < 0.05) in the Type I and IIa fibers, respectively. Although Type I fiber power was unaltered, the IIa fibers increased 2.5-fold from 24.6+/-2.8 to 56.2+/-3.9 microN x FL x s(-1). When power was normalized for cell size, the power was still elevated twofold. These data suggest that tapering induces alterations in the contractile properties of single muscle fibers. Further, it appears that the Type IIa fibers are more affected than the Type I fibers by the taper. The increased size, strength, velocity, and power of the IIa fibers may be responsible for the improvements in whole muscle strength and power after the taper.
Article
TRAPPE, S., D. COSTILL, and R. THOMAS. Effect of swim taper on whole muscle and single muscle fiber contractile properties. Med. Sci. Sports Exerc., Vol. 32, No. 12, 2000, pp. 48-56. Purpose: To examine the changes in whole muscle function and single cell contractile properties of Type I and II muscle fibers from the deltoid muscle of highly trained swimmers before and after a 21-d reduction in training volume (taper). Methods: Six college male swimmers (age, 20 +/- 1 yr; height, 187 +/- 2 cm, weight, 79 +/- 3 kg, fat, 7 +/- 1%) who had been, on average, swimming 6200 m.d-1 for 5 months before the taper participated in this investigation. Results: Whole muscle power increased (P < 0.05) 17% and 13% on the swim bench and swim power tests, respectively. Swim times improved by 4% (range: 3.0-4.7%; P < 0.05). There was no change in Type I fiber diameter, whereas Type IIa fibers were 11% larger (P < 0.05) after taper. Peak force (Po) of the Type I fibers was unaffected by the taper but increased (P < 0.05) from 0.63 +/- 0.02 to 0.82 +/- 0.05 mN in the IIa fibers. However, the specific force (Po/CSA) of the IIa fibers was unchanged. Shortening velocity (Vo) was 32% and 67% faster (P < 0.05) in the Type I and IIa fibers, respectively. Although Type I fiber power was unaltered, the IIa fibers increased 2.5-fold from 24.6 +/- 2.8 to 56.2 +/- 3.9 µN.FL.s-1. When power was normalized for cell size, the power was still elevated twofold. Conclusions: These data suggest that tapering induces alterations in the contractile properties of single muscle fibers. Further, it appears that the Type IIa fibers are more affected than the Type I fibers by the taper. The increased size, strength, velocity, and power of the IIa fibers may be responsible for the improvements in whole muscle strength and power after the taper.
Article
Skeletal muscle is characterized by its ability to dynamically adapt to variable levels of functional demands. During periods of insufficient training stimulus, muscular detraining occurs. This may be characterized by a decreased capillary density, which could take place within 2--3 wk of inactivity. Arterial-venous oxygen difference declines if training stoppage continues beyond 3--8 wk. Rapid and progressive reductions in oxidative enzyme activities bring about a reduced mitochondrial ATP production. The above changes are related to the reduction in VO(2max) observed during long-term training cessation. These muscular characteristics remain above sedentary values in the detrained athlete but usually return to baseline values in recently trained individuals. Glycolytic enzyme activities show nonsystematic changes during periods of training cessation. Fiber distribution remains unchanged during the initial weeks of inactivity, but oxidative fibers may decrease in endurance athletes and increase in strength-trained athletes within 8 wk of training stoppage. Muscle fiber cross-sectional area declines rapidly in strength and sprint athletes, and in recently endurance-trained subjects, whereas it may increase slightly in endurance athletes. Force production declines slowly and in relation to decreased EMG activity. Strength performance in general is readily maintained for up to 4 wk of inactivity, but highly trained athletes' eccentric force and sport-specific power, and recently acquired isokinetic strength, may decline significantly.
Article
The power output generated with different barbell loads and which resistance generated the maximum mechanical power output (Pmax) during explosive bench press-type throws (BT) in a smith machine device were investigated in power-trained athletes. Thirty-one rugby league players were tested for 1 repetition maximum (1RM) free-weight bench press strength (1RM BP). Maximal power output was assessed by the Plyometric Power System during BT using resistances of 40, 50, 60, 70, and 80 kg (BT P40, BT P50, BT P60, BT P70, and BT P80). It was found that BT Pmax occurred with resistance of 70.1 +/- 7.9 kg, representing 55 +/- 5.3% of 1RM BP of 129.7 +/- 14.3 kg. The power output with all loads except the BT P70 were different from the BT Pmax. The BT P70 and BT P80 were not different from each other. Furthermore, the BT P60 and BT P80 were not different from each other. This suggests that although resistances of 55% 1RM BP may maximize power output during explosive BT, loads in the range of 46-62% also allow for high power outputs. Resistances of 31-45% of 1RM BP resulted in significantly lower power outputs. Compared with previous research of BT in strength-trained athletes, the results of this investigation suggest that power-trained athletes may generate their Pmax at higher percentages of 1RM.
Article
The taper is a progressive nonlinear reduction of the training load during a variable period of time, in an attempt to reduce the physiological and psychological stress of daily training and optimize sports performance. The aim of the taper should be to minimize accumulated fatigue without compromising adaptations. This is best achieved by maintaining training intensity, reducing the training volume (up to 60-90%) and slightly reducing training frequency (no more than 20%). The optimal duration of the taper ranges between 4 and more than 28 d. Progressive nonlinear tapers are more beneficial to performance than step tapers. Performance usually improves by about 3% (usual range 0.5-6.0%), due to positive changes in the cardiorespiratory, metabolic, hematological, hormonal, neuromuscular, and psychological status of the athletes.
Article
It was hypothesized that metabolic adaptations in single muscle cells after a taper period are fiber type (I and II) specific and protocol regimen dependent. After 7-wk intensive endurance training, 22 male cyclists (VO2max=4.42 +/- 0.40 L.min(-1)) were randomly assigned to one of three 7-d taper groups: the control group (CON, N=7) continued weekly training, the first experimental group (INT) maintained training intensity but reduced duration (N=7), and the second experimental group (DUR) maintained training duration but reduced exercise intensity (N=8). Each cyclist completed a simulated 40-km time trial (40TT) before and after tapering on a set of wind-loaded rollers using their own bicycle. Muscle biopsies were taken immediately before the 40TT both before and after tapering, and analyzed for mATPase, succinate dehydrogenase (SDH), cyctochrome oxidase (CYTOX), alpha-glycerolphosphate dehydrogenase (alpha-GPD), and beta-hydroxyacyl CoA dehydrogenase (beta-HOAD) in Type I and II fibers, separately, using quantitative histochemistry. The results showed significant (P< or =0.05) increases in SDH (Type I) and mATPase, CYTOX, beta-HOAD, and SDH (Type II fibers) in the INT group, and significant increases in CYTOX (Type I) and beta-HOAD (Type I and II fibers) in the DUR group. Regression analysis showed that the change (posttaper minus pretaper) in simulated 40-km endurance time was correlated with the change in CYTOX and SDH activity for all groups combined (r2=0.62-0.72). These results demonstrated that the metabolic properties of different fiber types are altered with tapering, that the type of taper protocol used influences their physiological adaptation, and that improvements in simulated 40-km endurance time were related to changes in metabolic properties of the muscle at the single fiber level.
Article
The ability to optimise muscular power output is considered fundamental to successful performance of many athletic and sporting activities. Consequently, a great deal of research has investigated methods to improve power output and its transference to athletic performance. One issue that makes comparisons between studies difficult is the different modes of dynamometry (isometric, isokinetic and isoinertial) used to measure strength and power. However, it is recognised that isokinetic and isometric assessment bear little resemblance to the accelerative/decelerative motion implicit in limb movement during resistance training and sporting performance. Furthermore, most people who train to increase power would have limited or no access to isometric and/or isokinetic dynamometry. It is for these reasons and for the sake of brevity that the findings of isoinertial (constant gravitational load) research will provide the focus of much of the discussion in this review. One variable that is considered important in increasing power and performance in explosive tasks such as running and jumping is the training load that maximises the mechanical power output (Pmax) of muscle. However, there are discrepancies in the research as to which load maximises power output during various resistance exercises and whether training at Pmax improves functional performance is debatable. There is also some evidence suggesting that Pmax is affected by the training status of the individuals; however, other strength variables could quite possibly be of greater importance for improving functional performance. If Pmax is found to be important in improving athletic performance, then each individual’s Pmax needs to be determined and they then train at this load. The predilection of research to train all subjects at one load (e.g. 30% one repetition maximum [1RM]) is fundamentally flawed due to inter-individual Pmax differences, which may be ascribed to factors such as training status (strength level) and the exercise (muscle groups) used. Pmax needs to be constantly monitored and adjusted as research suggests that it is transient. In terms of training studies, experienced subjects should be used, volume equated and the outcome measures clearly defined and measured (i.e. mean power and/or peak power). Sport scientists are urged to formulate research designs that result in meaningful and practical information that assists coaches and strength and conditioning practitioners in the development of their athletes.