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Effects of velocity loss during resistance training on athletic performance, strength gains and muscle adaptations
Abstract
We compared the effects of two resistance training (RT) programs only differing in the repetition velocity loss allowed in each set: 20% (VL20) vs 40% (VL40) on muscle structural and functional adaptations. Twenty-two young males were randomly assigned to a VL20 (n = 12) or VL40 (n = 10) group. Subjects followed an 8-week velocity-based RT program using the squat exercise while monitoring repetition velocity. Pre- and post-training assessments included: magnetic resonance imaging, vastus lateralis biopsies for muscle cross-sectional area (CSA) and fiber type analyses, one-repetition maximum strength and full load-velocity squat profile, countermovement jump (CMJ), and 20-m sprint running. VL20 resulted in similar squat strength gains than VL40 and greater improvements in CMJ (9.5% vs 3.5%, P < 0.05), despite VL20 performing 40% fewer repetitions. Although both groups increased mean fiber CSA and whole quadriceps muscle volume, VL40 training elicited a greater hypertrophy of vastus lateralis and intermedius than VL20. Training resulted in a reduction of myosin heavy chain IIX percentage in VL40, whereas it was preserved in VL20. In conclusion, the progressive accumulation of muscle fatigue as indicated by a more pronounced repetition velocity loss appears as an important variable in the configuration of the resistance exercise stimulus as it influences functional and structural neuromuscular adaptations.
... The use of velocity-based training has gained popularity in recent years [31,32]. This training method involved tracking the bar velocity while performing HRT, and the cessation of each set is determined by a specific velocity loss threshold [31,32]. ...
... The use of velocity-based training has gained popularity in recent years [31,32]. This training method involved tracking the bar velocity while performing HRT, and the cessation of each set is determined by a specific velocity loss threshold [31,32]. This method to perform HRT may allow for a more individualized prescription of training volume to optimise adaptations [31,32]. ...
... This training method involved tracking the bar velocity while performing HRT, and the cessation of each set is determined by a specific velocity loss threshold [31,32]. This method to perform HRT may allow for a more individualized prescription of training volume to optimise adaptations [31,32]. Similarly, the use of multi-joint ISO in athletes' physical preparation has also increased in recent years, as studies have reported that the inclusion of ISO as compared to traditional strength training alone may result in greater strength improvement [24][25][26]. ...
Purpose This study compared the acute effects of a session of isometric strength training (ISO) with heavy resistance training (HRT) training on 20-m sprint, countermovement jump (CMJ) and isometric mid-thigh pull (IMTP) performance. Methods Ten resistance-trained athletes (age: 26.7 ± 6.2 years, body mass: 71.5 ± 16.2 kg, height: 1.68 ± 0.10 m) performed baseline measures for 20-m sprint, CMJ and IMTP prior to either an ISO or HRT session. During both training sessions, participants performed back squats, Romanian deadlift and split squat. Post-test performances were measured 5 min and 24 h after each training session. Participants returned a week later to perform the other training session. Results A significant time × condition effect was found for 20-m sprint time (P = 0.007) and IMTP peak force (P = 0.003). Main time effect was observed for 20-m sprint (P < 0.001), CMJ height (P < 0.001) and IMTP peak force (P < 0.001). HRT resulted in a greater increase in sprint time at 5 min (0.17 ± 0.12 vs. 0.06 ± 0.05 s, P = 0.013, g = 1.15) and 24 h (0.01 ± 0.09 vs. 0.00 ± 0.05 s, P = 0.004, g = 1.32) post-training as compared to ISO. Similarly, HRT resulted in a significantly larger reduction in IMTP peak force than ISO at both 5 min (− 363.3 ± 248.8 vs. − 98.9 ± 230.3 N, P = 0.024, g = 1.06) and 24 h (− 289.2 ± 256.2 vs. 37.9 ± 177.8 N, P = 0.004, g = 1.42) post-training. Total impulses generated during each exercise were greater during ISO than HRT (P < 0.001-0.006). Rating of perceived recovery post 24 h was higher in ISO than HRT (P = 0.002). Conclusion The above results indicated that acute HRT led to a greater reduction in sprinting strength performance and lower perceived recovery post-24 h than ISO.
... 6,10 In that sense, it has been reported that training adaptations are velocity-specific. 11 Thus, the most significant number of repetitions performed near the target training velocity, the largest increases in neuromuscular performance. 10,11 Therefore, lower velocity loss (VL; ie, lower fatigue) during the set results in greater neuromuscular performance due to lower metabolic and hormonal disturbances (ie, lower increases in blood ammonia, lactate, insulin-like growth factor, cortisol, or creatine kinase). ...
... 11 Thus, the most significant number of repetitions performed near the target training velocity, the largest increases in neuromuscular performance. 10,11 Therefore, lower velocity loss (VL; ie, lower fatigue) during the set results in greater neuromuscular performance due to lower metabolic and hormonal disturbances (ie, lower increases in blood ammonia, lactate, insulin-like growth factor, cortisol, or creatine kinase). 6,11,12 Given the known detrimental effects of fatigue on subsequent neuromuscular performance, monitoring VL during the set might explain the acute change in vertical jump performance. ...
... 10,11 Therefore, lower velocity loss (VL; ie, lower fatigue) during the set results in greater neuromuscular performance due to lower metabolic and hormonal disturbances (ie, lower increases in blood ammonia, lactate, insulin-like growth factor, cortisol, or creatine kinase). 6,11,12 Given the known detrimental effects of fatigue on subsequent neuromuscular performance, monitoring VL during the set might explain the acute change in vertical jump performance. ...
Purpose:
This study aimed to (1) evaluate the acute effects of different interrepetition rest full-squat protocols on countermovement jump (CMJ) height, velocity loss (VL), and skin temperature (Tsk) and (2) determine whether the VL, the changes in Tsk, or the individual strength level is associated with the change in CMJ height.
Methods:
Sixteen resistance-trained men randomly performed 3 squat protocols at maximal intended velocity with 60% of the 1-repetition maximum (sets × repetitions [interrepetition rest]): traditional (2 × 6 [0 s]), cluster 2 (2 × 6 [30 s every 2 repetitions]), and cluster 1 (1 × 12; [36 s every repetition]), plus a control session. CMJ height was assessed before and 2, 4, and 8 minutes after the protocols.
Results:
There was a significant main effect of protocol for the VL (F = 20.54, P < .001) and loss in mean power (F = 12.85, P < .001; traditional > cluster 2 > cluster 1). However, we found a comparable reduction of CMJ height after 8 minutes: traditional (-3.4% [4.2%]), cluster 2 (-5.3% [4.9%]), cluster 1 (-5.4% [2.9%]), and control (-4.2% [3.6%]). Overall, mean Tsk acutely decreased after all the protocols. Higher individual strength level (but not VL or the changes in Tsk) was associated with lower CMJ-height loss (P < .05).
Conclusions:
Although different interrepetition rest full-squat protocols may alter the loss in velocity and power, they result in a similar decrease in Tsk and CMJ height, which could be more influenced by individual strength level than VL or changes in Tsk.
... During a resistance exercise, by performing every repetition at a maximal effort in the concentric phase, a gradual and unintentional decrease in velocity is observed as fatigue ensues (6,13). Therefore, strength and conditioning coaches can accurately regulate intra-set volume when a specific drop in velocity is achieved (i.e., percentage of velocity loss relative to the fastest repetition) (22,23). It is particularly relevant for designing optimal RT programs since the dose-response relationship between volume and gains in muscle strength may be represented by an inverted "U-shaped" curve (25,27). ...
... Overall, it was shown that low (<15%) and moderate VL thresholds (15-30%) resulted in similar gains in muscle strength (3) in a time-efficient manner compared to high intra-set VL (>30%). In addition, low to moderate VL seem to induce greater adaptations in power-related tasks (i.e., sprints and jumps) (22,23,27) than high VL thresholds (>30%). Collectively, these results suggest that a high volume of intra-set repetitions does not induce additional gains in muscle strength and powerrelated tasks, despite the high levels of discomfort and fatigue experienced during the sets. ...
... Accurately identifying velocity reductions when the bar moves at high or slow velocity can be a complex task for resistance-trained individuals with little experience using PVL. In the retest, these small intensity effects on PVL accuracy levels were not evidenced, which 22 reinforces the hypothesis that practice with feedback is important for improving PVL accuracy and reliability. This hypothesis is consistent with previous findings in the literature (16,33). ...
... 9,10 Over a training period, lower velocity loss thresholds (ie, < 25%) appear to facilitate improvements in muscle power, jumping performance, and maximal strength (1RM) 9 ; while higher thresholds (close to set failure) seem more beneficial for muscle hypertrophy. 6,10 Intriguingly, most previous studies have not controlled for the total number of repetitions per session, 11,12 which raises the question of whether the effects were due to velocity losses, the training volume, or a combination of the two. ...
... The difference in training volume has typically been ∼40%. [11][12][13][14] Strength training investigations for short periods (eg, 6-12 wk) suggest that the optimal training volume is higher for hypertrophy than for strength gains, 15 which implies that the inferior hypertrophy seen with lower thresholds of velocity loss may simply be due to insufficient training volume. Following this line of thinking, we recently equalized the training volume and showed similar strength improvements and hypertrophy of the vastus lateralis after 9 weeks of unilateral knee extension and legpress training, using either a 15% or 30% velocity loss threshold. ...
... In previous studies, HVL training has resulted in a larger training volume than LVL, due to the same number of sets but different numbers of repetitions per set. [12][13][14]31 Here, we aimed to equalize the training volume by prescribing more sets for the LVL than HVL. However, because of individual differences in the number of repetitions completed in each set, regardless of similar velocity loss, training volumes could not be reliably predicted. ...
Aims:
In the present intervention study, low-velocity-loss (LVL) versus high-velocity-loss (HVL) thresholds in the squat and bench press were compared for changes in muscle strength, power, and hypertrophy.
Methods:
Strength-trained volunteers (7♀ and 9♂; age: 27.2 [3.4] y; height: 174.6 [8.0] cm; body mass: 75.3 [10.1] kg) were randomized into an LVL or HVL threshold group (LVL n = 3♀ + 5♂, and HVL n = 4♀ + 4♂). Training took place 3 times per week over 6 weeks (loads: ∼75%-90% of 1-repetition maximum [1RM]). The thresholds of LVLs and HVLs were set at 20% and 40% of maximal velocity, respectively, for the squat, and at 30% and 60%, respectively, for the bench press. Before and after the intervention, 1RM, leg press power, and squat jump were tested. The load (∼45% of 1RM) corresponding to 1-m/s velocity was assessed in all sessions for both exercises. In addition, the thickness of the vastus lateralis and triceps brachii and body composition (dual-energy X-ray absorptiometry [DEXA]) were measured.
Results:
Squat and bench-press 1RM increased similarly in both groups by 7% to 11% (SD: 4%-6%, P < .05). No group differences were observed for changes in jump height, leg press power, or DEXA lean mass. However, HVL showed a small increase in muscle thickness of the vastus lateralis compared with LVL (6 ± 6% [95% CI] group difference, P < .05).
Conclusion:
For strength-trained individuals, high-volume lower-velocity-loss thresholds were as effective as higher thresholds for improvements in 1RM strength; but local hypertrophy was seemingly elicited faster with higher velocity-loss thresholds.
... Accordingly, objective "velocity loss" thresholds have been proposed to adjust the target volume in a given exercise, an overall session, or throughout a block of training with the aim to selectively develop different physical qualities, such as muscular power (<20%), strength (ie, 20%-40%), and hypertrophy (>40%). 11,12 Tracking devices measuring velocity, such as accelerometrybased measurement units and linear position transducers, are needed to implement VBT. 13 These velocity trackers are widely commercialized, portable, and mostly affordable. However, their use is impractical in large groups sharing the same training environment (eg, machines or lifting platforms), or when trainees are required to move quickly and repeatedly from one exercise to the next. ...
... Second, while reporting PCV after every repetition allows for more data points to be collected, it is not aligned with the practical use of VBT, in which trainees are required to terminate a set only when velocity exceedes a threshold relative to the first repetition. 1,3,8,9,11 Moreover, the studies of Sindiani et al 14 Accordingly, the purpose of this study was to investigate if resistance-trained participants performing the bench press exercise to task failure can accurately perceive velocity loss at 20% and 40% relative to the first repetition. Participants completed 4 sets with 4 different loads selected across the spectrum of the individual loadvelocity relationship. ...
... Practically, this finding seems to encourage the use of PVL as a subjective VBT autoregulation method especially when the resistance training goal is to develop and maintain muscular power. 3,4,11,12,15,18,19,[25][26][27] Aligned with Sindiani et al 14 and Lazarus et al, 15 we also observed that the PVL error increased with consecutive repetitions, even when controlling for lifting velocity, PVL thresholds, and participants. As previously proposed, we presume that the reasons for this effect can stem from 2 main pathways that may also interact. ...
Purpose:
Velocity-based training is used to prescribe and monitor resistance training based on velocity outputs measured with tracking devices. When tracking devices are unavailable or impractical to use, perceived velocity loss (PVL) can be used as a substitute, assuming sufficient accuracy. Here, we investigated the accuracy of PVL equal to 20% and 40% relative to the first repetition in the bench-press exercise.
Methods:
Following a familiarization session, 26 resistance-trained men performed 4 sets of the bench-press exercise using 4 different loads based on their individual load-velocity relationships (∼40%-90% of 1-repetition maximum [1RM]), completed in a randomized order. Participants verbally reported their PVL at 20% and 40% velocity loss during the sets. PVL accuracy was calculated as the absolute difference between the timing of reporting PVL and the actual repetition number corresponding to 20% and 40% velocity loss measured with a linear encoder.
Results:
Linear mixed-effects model analysis revealed 4 main findings. First, across all conditions, the absolute average PVL error was 1 repetition. Second, the PVL accuracy was not significantly different between the PVL thresholds (β = 0.16, P = .267). Third, greater accuracy was observed in loads corresponding to the midportion of the individual load-velocity relationships (∼50%-60% 1RM) compared with lighter (<50% 1RM, β = 0.89, P < .001) and heavier loads (>60% 1RM, 0.63 ≤ β ≤ 0.84, all P values < .001). Fourth, PVL accuracy decreased with consecutive repetitions (β = 0.05, P = .017).
Conclusions:
PVL can be implemented as a monitoring and prescription method when velocity-tracking devices are impractical or absent.
... Consequently, authors have investigated the effects of RT programs that differ in the VL reached. Previous research found that despite the lower level of effort in 20% VL compared with 40% VL, similar strength gains were induced by both RT programs (21). However, the 40% VL group had lesser improvements in countermovement jump and witnessed a reduction of the IIx myosin heavy chain toward more oxidative characteristics (21). ...
... Previous research found that despite the lower level of effort in 20% VL compared with 40% VL, similar strength gains were induced by both RT programs (21). However, the 40% VL group had lesser improvements in countermovement jump and witnessed a reduction of the IIx myosin heavy chain toward more oxidative characteristics (21). This suggests that training reaching different levels of VL could induce particular physiological adaptations such as muscle oxygenation during exercise. ...
... After 5 days, in a second session, subjects performed 8 repetitions of the same exercise with the 1 m·s 21 load while muscle oxygenation in the vastus lateralis and vastus medialis was assessed using NIRS. In brief, following a protocol previously described (21), both intervention groups performed the training at the same relative load but reached different velocity loss percentages in the set (20VL vs. 40VL). The subjects were required to maintain their daily habits, avoiding new participation in any type of lower-limb training, strenuous physical activity, or sports competition during the intervention course. ...
The present study compared, for the first time, the effects of 6 weeks of 20% (20VL) vs. 40% (40VL) velocity loss (VL) resistance training (RT) programs on muscle oxygen dynamics during the squat exercise. Twenty-three young men (21.4 ± 2.4 years) were randomly allocated into the 20VL group (n = 8), 40VL group (n = 7), or control group (CG; n = 8). The RT program consisted of 3 sets of Smith machine back squat exercise at 20VL or 40VL with a 3-minute rest between sets, twice per week for 6 weeks. Tissue oxygenation index (TOI) was measured using near-infrared spectroscopy in the vastus medialis and vastus lateralis during a squat test (8-repetition 1 m·s−1 load test), and the maximum (maxTOI) and minimum (minTOI) TOIs were measured during a 3-min recovery period. After the 6-week RT program, TOI increased significantly at the beginning of the test in both muscles (during the first 4 repetitions in the vastus lateralis and 5 repetitions in the vastus medialis) in the 20VL group (p < 0.05), with nonsignificant changes in the 40VL group and CG. The maxTOI was significantly increased in the vastus medialis (+3.76%) and vastus lateralis (+3.97%) after the training only in the 20VL group (p < 0.05). The minTOI in the vastus medialis reached during the test remained unchanged postintervention for both training groups, with the CG showing significantly higher values compared with the 20VL group (+14.1%; p < 0.05). In conclusion, depending on the VL reached during a squat RT program, different changes in muscle oxygen dynamics can be expected. Training at 20% of VL improves metabolic efficiency and the reoxygenation peak after the set.
... Accordingly, to attain a high velocity concentric stimuli coaches might consider using velocity based training devices to monitor and maintain movement velocity within specific thresholds during an exercise. This could promote favorable adaptations such as maintenance of type II muscle fibres that are critical for rapid limb movements and force production when decelerating rapidly (Pareja-Blanco et al., 2017). ...
... Practitioners may also look to utilise velocity based resistance training strategies that aim to maximise the amount of repetitions performed with high movement velocity (i.e., low % velocity loss) which are known to be conducive to activities, such as decelerating, where rapid force production and lower-limb movements are required (Pareja-Blanco et al., 2017). ...
... In order to specifically target the development of faster knee joint angular velocities these findings illustrate the importance of including both field based deceleration coordination training, together with gym based resistance training approaches, within conditioning programs. For example, velocity based resistance training (VBT) designed to maximize the amount of repetitions performed with high movement velocity (low % velocity loss) has been shown to result in enhanced neuromuscular performance, stimulating improvements in fundamental actions like deceleration in soccer players(Pareja- Blanco et al., 2017). ...
Horizontal accelerations and decelerations are crucial components underpinning the many fast changes of speed and direction that are performed in team sports competitive match play. Extensive research has been conducted into the assessment of horizontal acceleration and the underpinning neuromuscular performance determinants, leading to evidence-informed guidelines on how to best develop specific components of a team sport players horizontal acceleration capabilities. Unlike horizontal acceleration, little scientific research has been conducted into how to assess horizontal deceleration, meaning the neuromuscular performance determinants underpinning horizontal deceleration are largely based on anecdotal opinion or qualitative observations. Therefore, the overall purpose of this thesis was to investigate the neuromuscular determinants of maximal horizontal deceleration ability in team sport players. Furthermore, since there are no recognised procedures on how to assess maximal horizontal deceleration ability, an important and novel aim of this thesis was to develop a test capable of obtaining reliable and sensitive data on a team sport player’s maximal horizontal deceleration ability. In part one of this thesis (chapter three) a systematic review and meta-analysis identified that high-intensity (< -2.5 m.s-2) decelerations were more frequently performed than equivalently intense accelerations (> 2.5 m.s-2) in most elite team sports competitive match play, signifying the importance of developing maximal horizontal deceleration ability in team sport players. In chapter four, a new test of maximal horizontal deceleration ability (named the acceleration-deceleration ability test – ADA test), measured using radar technology, identified a number of kinematic and kinetic variables that had good intra- and inter-day reliability and were sensitive to detecting small-to-moderate changes in maximal horizontal deceleration ability. The ADA test was used in chapters five to seven to examine associations with isokinetic eccentric and concentric knee strength capacities and countermovement and drop jump kinetic and kinematic variables, respectively. Using the neuromuscular and biomechanical determinants identified to be important for horizontal deceleration ability within this thesis, in addition to other contemporary research findings, the final part of this thesis developed an evidence-based framework that could be used by practitioners to help inform decisions on training solutions for improving horizontal deceleration ability – named the dynamic braking performance framework.
... A proper methodology for this purpose would be the velocity-based method, which has recently been found highly accurate to be implemented in free-weight and machine-based training modalities (25). This methodology would allow researchers to use the load-velocity relationship to accurately program intensity, thus avoiding the mismatches that normally occur when this parameter is solely programmed by using fixed weights relative to the pre-training 1RM (26). On the other hand, most previous investigations comparing free-weight and machine-based modalities set intra-set volume by prescribing a given number of repetitions to failure (e.g., 8RM) (12,13,16), which could be dangerous (27), inefficient (23), and even detrimental to Copyright © 2023 by the American College of Sports Medicine. ...
... Unauthorized reproduction of this article is prohibited. (26). This limitation on the nRM methodology could be solved by using different velocity-derived strategies, such as the velocity loss (28), effort index (29) or level of effort (30), which make it possible to program different intra-set volume thresholds. ...
Purpose:
To compare the effects of free-weight and machine-based resistance training on strength, hypertrophy, and joint discomfort.
Methods:
Thirty-eight resistance-trained men participated in an 8-week resistance program allocated into free-weight (n = 19) or machine-based (n = 19) groups. Training variables were identical for both modalities, so they only differed in the use of barbells or machines to execute the full squat, bench press, prone bench pull, and shoulder press exercises. The velocity-based method was implemented to accurately adjust the intensity throughout the program. Strength changes were evaluated using 8 velocity-monitored loading tests (4 exercises x 2 modalities) and included the relative one-repetition maximum (1RMRel), as well as the mean propulsive velocity against low (MPVLow) and high (MPVHigh) loads. Ultrasound-derived cross-sectional area (CSA) of quadriceps (proximal and distal regions), pectoralis major, and rectus abdominis was measured to examine hypertrophy. Complementarily, WOMAC and DASH questionnaires were administrated to assess changes in lower- and upper-limb joint discomfort. Outcomes were compared using ANCOVA and percentage of change (∆) statistics.
Results:
Each group significantly (p < 0.001) increased 1RMRel, MPVLow, and MPVHigh for both modalities tested, but especially in the one they trained. When considering together the 8 exercises tested, strength changes for both modalities were similar (∆ differences ≤1.8%, p ≥ 0.216). Likewise, the CSA of all the muscles evaluated was significantly increased by both modalities, with no significant differences between them (∆ difference ≤ 2.0%, p ≥ 0.208). No between-group differences (p ≥ 0.144) were found for changes in stiffness, pain, and functional disability levels, which were reduced by both modalities.
Conclusions:
Free-weight and machine-based modalities are similarly effective to promote strength and hypertrophy without increasing joint discomfort.
... Another study by Banyard et al. [9] found likely improvements in the fastest velocity of loaded CMJ (PV-CMJ) in 24 trained men with VBRT. The systematic review [18] also supports the use of velocity loss metrics as a monitoring tool in strength training, as it can improve CMJ height to varying degrees. ...
... High velocity-loss and high repetition resistance training can result in a significant reduction in type IIX fibers, which may negatively impact strength development and prolong recovery [20]. Velocity-based prescription and monitoring velocity loss can mitigate these issues by ensuring higher quality completion of each repetition and reducing unnecessary mechanical stress and fatigue [18]. The present study highlights the importance of heavy intensity and slightly fewer repetitions in enhancing explosive power. ...
Citation: Zhang, M.; Li, D.; He, J.; Liang, X.; Li, D.; Song, W.; Ding, S.; Shu, J.; Sun, X.; Sun, J. Effects of Velocity-Based versus Abstract: The purpose of this study was to compare the impact of velocity-based resistance training (VBRT) and percentage-based resistance training (PBRT) on anaerobic ability, sprint performance, and jumping ability. Eighteen female basketball players from a Sport College were randomly divided into two groups: VBRT (n = 10) and PBRT (n = 8). The six-week intervention consisted of two sessions per week of free-weight back squats with linear periodization from 65% to 95%1RM. In PBRT, the weights lifted were fixed based on 1RM percentage, while in VBRT, the weights were adjusted based on individualized velocity profiles. The T-30m sprint time, relative power of countermovement jump (RP-CMJ), and Wingate test were evaluated. The Wingate test assessed peak power (PP), mean power (MP), fatigue index (FI), maximal velocity (Vmax), and total work (TW). Results showed that VBRT produced a very likely improvement in RP-CMJ, Vmax, PP, and FI (Hedges' g = 0.55, 0.93, 0.68, 0.53, respectively, p < 0.01). On the other hand, PBRT produced a very likely improvement in MP (Hedges' g = 0.38) and TW (Hedges' g = 0.45). Although VBRT showed likely favorable effects in RP-CMJ, PP, and Vmax compared to PBRT (p < 0.05 for interaction effect), PBRT produced greater improvements in MP and TW (p < 0.05 for interaction effect). In conclusion, PBRT may be more effective in maintaining high-power velocity endurance, while VBRT has a greater impact on explosive power adaptations.
... Although no significant differences between groups were found at Post, the microdosing group exhibited a greater intragroup (Pre-Post) magnitude of effects, which was accompanied by a significantly smaller reduction in CMJ height recorded across the various training sessions. This difference in the magnitude of the changes may be partially explained by studies proving the superiority of training sessions in which the training intensity remains elevated throughout the session as a result of a reduced workload [36]. The impact of these intensity losses has been repeatedly contrasted in the scientific literature and is linked not only to mechanical fatigue indices (jump height, movement velocity or sprint performance decrements), but also to biochemical [37] and hormonal markers [38,39]. ...
... The impact of these intensity losses has been repeatedly contrasted in the scientific literature and is linked not only to mechanical fatigue indices (jump height, movement velocity or sprint performance decrements), but also to biochemical [37] and hormonal markers [38,39]. As can be inferred from recent evidence [36,40], the interrelation of all of these factors creates an environment that, depending on its configuration, may modify the training stimulus received, facilitating or limiting certain adaptations. Accordingly, a microdose-based load distribution appears to ensure greater training efficiency by guaranteeing a higher specificity of the stimulus received, because of the lower distortion generated by current fatigue. ...
Introduction:
The implementation of optimal sprint training volume is a relevant component of team sport performance. This study aimed to compare the efficiency and effectiveness of two different configurations of within-season training load distribution on sprint performance over 6 weeks.
Methods:
Twenty male professional FH players participated in the study. Players were conveniently assigned to two groups: the experimental group (MG; n = 11; applying the microdosing training methodology) and the control group (TG; n = 9; traditional training, with players being selected by the national team). Sprint performance was evaluated through 20 m sprint time (T20) m and horizontal force-velocity profile (HFVP) tests before (Pre) and after (Post) intervention. Both measurements were separated by a period of 6 weeks. The specific sprint training program was performed for each group (for vs. two weekly sessions for MG and TG, respectively) attempting to influence the full spectrum of the F-V relationship.
Results:
Conditional demands analysis (matches and training sessions) showed no significant differences between the groups during the intervention period (p > 0.05). No significant between-group differences were found at Pre or Post for any sprint-related performance (p > 0.05). Nevertheless, intra-group analysis revealed significant differences in F0, Pmax, RFmean at 10 m and every achieved time for distances ranging from 5 to 25 m for MG (p < 0.05). Such changes in mechanical capabilities and sprint performance were characterized by an increase in stride length and a decrease in stride frequency during the maximal velocity phase (p < 0.05).
Conclusion:
Implementing strategies such as microdosed training load distribution appears to be an effective and efficient alternative for sprint training in team sports such as hockey.
... It has been suggested VBT should utilize velocity thresholds of 10-20% to optimize performance adaptations [1]. Despite performing less work, recent research suggests VBT may provide a better means of improving muscular strength and athletic performance [4,5] than more traditional methods of RE training. Additionally, monitoring CMV at multiple training loads enables strength and conditioning personnel to not only predict an athlete's 1RM [6], but also determine how many more repetitions an athlete can perform in a set until failure [7]. ...
... Past studies [8,9,12,[14][15][16]19], all used a similar methodology of performing one to three repetitions at given intensities, while our study measured CMV for six consecutive repetitions at 75% 1RM and ten consecutive repetitions at 50% 1RM for both SQ and BP RE to determine if PUSH could track velocity loss across a RE set. The purpose of VBT is to monitor fluctuations in CMV in real time [2], as acute muscular fatigue has been reported to influence CMV [3] and a drop in CMV below a predetermined threshold can be used to terminate a set [4]. The information in Table 3, suggests PUSH can accurately monitor velocity loss in real time as changes in CMV compared favorably between PUSH and MC across the first and second halves of a set, for SQ and BP at 50% and 75% 1RM. ...
The purpose of this investigation was to compare concentric movement velocity (CMV) measured with the PUSH Band (v2.0) and a Vicon motion capture system (MC) during the back squat (SQ) and the bench press (BP) resistance exercises (RE). Twelve resistance-trained males (26.0 ± 5.5 years; 175.6 ± 4.9 cm; 96.3 ± 15.8 kg) completed ten repetitions at 50% of one-repetition maximum (1RM), and six repetitions at 75% 1RM for both BP and SQ. Four PUSH devices were utilized and attached to the subject’s right forearm, the center barbell, left and right sides of the barbell. MC markers were placed on top of each PUSH device. An overall analysis using a series of least-squares means contrasts suggested CMV did not differ (p > 0.05) between measurement technologies when position, RE, intensity and repetitions were combined. PUSH exhibited the highest Intraclass Correlation Coefficients (ICC = 0.835–0.961) and Pearson Product-Moment Correlation Coefficients (r = 0.742–0.949) at the arm and center barbell locations when compared with MC. The measurement of CMV between MC and PUSH compares favorably during moderate (i.e., 50%) and high (75%) intensity SQ and BP RE. These data indicate individuals can use the PUSH band v2.0 to accurately monitor CMV within a RE set for SQ and BP RE.
... Velocity-based training (VBT) requires measurement of the velocity at which the barbell is moved in the concentric phase with regard to different resistance exercises, which provide accurate, indirect estimations of the 1 RM without the need to perform a maximal lift [7,13,14]. It has been reported that barbell velocity during the bench press, back squat, and bench pull are highly correlated with training intensity in terms of %1RM [15][16][17][18]. It has been further underlined that controlling barbell velocity is a good way to monitor resistance training intensities [19,20]. ...
Background: Velocity-based training (VBT) requires measurement of the velocity at which
the barbell is moved in the concentric phase with regard to different resistance exercises, which
provides accurate, indirect estimations of 1 RM. However, for assessing punch performance, no
study has been carried out to date. The purpose of this study was to analyse the reliability of the
GymAware linear transducer for the measurement of barbell velocity during the landmine push
throw (LPT) test using four loads. Methods: Twenty-five healthy, physically active male students,
aged 24.13 2.82 years, volunteered to take part in this study. The reliability of the LPT test was
measured at two separate visits, with a 2-day interval between them. One series of the test protocol
included four parts of the LPT test with progressively increasing loads (20, 25, 30, and 35 kg) and
5 min intervals for rests between loads. Results: For all four loads, excellent intra-rater and test–retest
reliability was noted for the mean force variable (ICC = 0.97–0.99). Additionally, very strong and
significant correlations were established between measurements (r = 0.96–0.99). Poor reliability was
observed for barbell height and total work (ICC below 0.5). A trend of decreasing reliability was
detected with increasing barbell load. Furthermore, measurements without the barbell throw were
more reliable than those with it. Conclusions: These results support the use of the GymAware linear
transducer to track barbell velocity during the LPT test. This device may have valuable practical
applications for strength and conditioning coaches. Therefore, we suggest that the LPT assessed with
the GymAware linear transducer may be a useful method for evaluating upper limb strength and
power during boxing punches.
... This contention is supported by the discrepancy in the literature regarding the effectiveness of various VL thresholds for inducing training adaptations. For instance, lower VL thresholds were equally effective and more beneficial for muscle strength and power adaptations, whereas higher VL thresholds were superior for muscle hypertrophy compared to lower ones [30]. However, when the volume of work was matched between different VL threshold groups, no differences were observed in muscle strength, hypertrophy or even gains in performance of athletic tasks [12, 13]. ...
Purpose
This study aimed to quantify the potential variability in the volume of work completed after reaching different velocity loss (VL) thresholds and determine the effects of sex, training status and history, as well as psychological traits on the reliability and magnitude of the amount of work completed after reaching different VL thresholds using different loads in the back-squat exercise.
Methods
Forty-six resistance-trained people (15 females and 31 males; 18 to 40 years of age) with a wide range of strength levels, training experience, and different training practices were recruited and performed a one-repetition maximum (1RM) test, and two repetitions to failure (RTF) tests 72 h apart. RTF tests were performed with 70, 80, and 90% of 1RM with 10 min of rest between sets. The Bland–Altman analysis for multiple observations per participant and equivalence tests were used to quantify the variability in the volume of work completed after reaching different VL thresholds, whereas linear and generalised mixed-effects models were used to examine the effects of different moderators on the stability and magnitude of the amount of work completed after reaching different VL thresholds.
Results
The findings of the present study question the utility of using VL thresholds to prescribe resistance training (RT) volume as the agreement in the amount of work completed across two consecutive testing sessions was not acceptable. Regardless of the load used, females completed more repetitions than males across VL thresholds, while males performed repetitions at higher velocities. In addition, individuals with higher levels of emotional stability also tended to perform more repetitions across VL thresholds. Finally, sex, choice of load, strength levels and training practices, as well as emotional stability affected the linearity of the repetition–velocity relationship and when sets terminated.
Conclusion
Using the same VL thresholds for all individuals, while assuming generalisability of the stimuli applied, would likely lead to variable acute physiological responses to RT and divergent neuromuscular adaptations over long term. Therefore, VL monitoring practices could be improved by considering sex, training status, history, and psychological traits of individuals due to their effects on the variability in responses to different VL thresholds.
... 6,11 Protocols that induce muscle failure have been found to elicit greater mechanical and metabolic stress, such as increased velocity loss, blood ammonia, lactate, cortisol, and creatine kinase levels, compared with nonfailure training. 11,12 For example, Morán-Navarro et al 13 reported significantly higher acute decline in velocity and jump height, as well as longer times of recovery following a RT protocol to muscle failure (3 × 10 against the 10-repetition maximum [10RM]) compared with lower levels of effort (3 × 5 and 6 × 5 repetitions against the 10RM load). Regarding long-term adaptations, Izquierdo-Gabarren et al 6 demonstrated that nonfailure RT including bench pull, seated cable row, lat pulldown, and power clean exercises resulted in greater gains in maximal strength, power output, and rowing performance compared with failure-based training in trained male rowers. ...
Purpose:
To evaluate the interference effects of various resistance-training (RT) protocols on rowing ergometer performance.
Methods:
Fourteen semiprofessional male rowers randomly completed 5 protocols in separate sessions: (1) control-no RT session was performed, (2) upper-body high-fatigue-4 sets to failure during the bench pull exercise, (3) upper-body low-fatigue-4 sets of 6 repetitions during the bench pull exercise, (4) lower-body high-fatigue-4 sets to failure during the leg-press exercise, and (5) lower-body low-fatigue-4 sets of 6 repetitions during the leg-press exercise. All sets were performed against the 12-repetition-maximum load with 2 minutes of interset rest. Following the completion of the protocols, subjects performed an all-out 1000-m rowing ergometer test.
Results:
Compared with the control condition, rowing ergometer performance was not significantly affected after the low-fatigue RT protocols (upper body: P ≥ .487; Δ = 0.0%-0.2%; lower body: P ≥ .200; Δ = -0.2%-0.5%), while it significantly declined following high-fatigue RT protocols (upper body: P ≤ .001; Δ = 1.0%-2.0%; lower body: P ≤ .002; Δ = 2.1%-2.5%). The average heart rate was significantly lower for the control condition compared with all RT protocols (P ≤ .043; Δ = 1.0%-1.5%).
Conclusions:
To minimize interference on rowing performance, coaches should prioritize the level of effort in RT protocols over specific exercises, specifically avoiding high-fatigue protocols that lead to failure before rowing practice.
... A decrease of ≥ 20% in velocity/power has been reported as an indicator of neuromuscular fatigue during resistance training www. (González-Badillo & Sánchez-Medina, 2010;Pareja-Blanco et al., 2017;Sánchez-Medina & González-Badillo, 2011). All analyses were performed in Microsoft Excel. ...
The aim of this study was to investigate the desired number of repetitions required to maintain a consistent maximum power output of concentric, eccentric, and eccentric overload in a flywheel Romanian deadlift (FW RDL). Fourteen male recreational athletes (27.9 ± 6.4 years old, 90 ± 10.7 kg, 180.7 ± 5.5 cm tall) participated in the study. They had a minimum of two years resistance training experience, but none of them had any experience in flywheel inertia training (FIT). The participants performed FW RDL on an FW device (kBox 3, Exxentric, ABTM, Bromma, Sweden). Each participant attended a single test session. The testing session consisted of four sets of 14 repetitions of the RDL. Both the first and second repetitions of each set were used to ‘increase momentum’ and were excluded from data analysis. Each set incorporated different inertial loads. The order of inertial load settings was randomised for each participant. A five-minute inter-set rest period was given to allow the cessation of any fatigue effects and to enable adequate recovery. During the repetition analysis, a ≥ 20% drop in value from the preceding repetition was used as a cut-off point and recorded. The optimal number of repetitions required to maintain peak concentric and eccentric power was between 10 and 11, whereas 6 to 8 repetitions is advised to maintain eccentric overload.
... Repetitions-to-failure tests were introduced earlier due to their ease of implementation, as they do not require sophisticated equipment, making them suitable for widespread use in various training environments [11]. However, since the fatigue induced by performing repetitions until muscular failure can interfere with training goals [12], a less prone to fatigue method based on lifting velocity monitoring has recently gained popularity in the strength and conditioning field. Notably, recent research has evidenced that lifting velocity can provide estimates of 1RM with comparable or potentially greater accuracy than repetitions-to-failure tests [13][14][15]. ...
Resistance training intensity is commonly quantified as the load lifted relative to an individual's maximal dynamic strength. This approach, known as percent-based training, necessitates evaluating the one-repetition maximum (1RM) for the core exercises incorporated in a resistance training program. However, a major limitation of rigid percent-based training lies in the demanding nature of directly testing the 1RM from technical, physical and psychological perspectives. A potential solution that has gained popularity in the last two decades to facilitate the implementation of percent-based training involves the estimation of the 1RM by recording the lifting velocity against submaximal loads. This review examines the three main methods for prescribing relative loads (%1RM) based on lifting velocity monitoring: (i) velocity zones, (ii) generalized load-velocity relationships, and (iii) individualized load-velocity relationships. The article concludes by discussing a number of factors that should be considered for simplifying the testing procedures while maintaining the accuracy of individualized L-V relationships to predict the 1RM and establish the resultant individualized %1RM-velocity relationship: (i) exercise selection, (ii) type of velocity variable, (iii) regression model, (iv) number of loads, (v) location of experimental points on the load-velocity relationship, (vi) minimal velocity threshold, (vii) provision of velocity feedback, and (viii) velocity monitoring device.
... In addition, the actual 1RM of an athlete can fluctuate in a relatively short time because of several intrinsic and extrinsic factors (González . Research have also strongly advised against frequently testing 1RM to solve this issue, seeing that there are many feasibility complications with this practice, especially across multiple lifts (Pareja-Blanco et al., 2017). ...
Introduction: This study aimed to determine if adjusting the loads via velocity-based training (VBT) in each session is more efficient in monitoring the relative intensity than programming loads assessing 1RM pre-training.
Methods: To achieve this, six national level sprinters were randomly divided into two groups, i.e., adjusting loads (AL, n = 3) and not adjusting loads (NAL, n = 3), during twelve sessions of a squat training (ST) program. During this training intervention, the AL group adjusted the intensity for each session in the squat exercise depending on the speed the load was lifted after warmup. The NAL group, instead, progressed in the squat exercise referring to the 1RM estimated at pre-test. In addition, Parallel Squat (PSQ), Countermovement Jump (CMJ), Squat Jump (SJ), 30 m sprint standing start (30S) and 30 m sprint flying start (30F) tests were carried out before and after conducting the ST program.
Results: Interestingly, AL performed the ST near their estimated velocities at 70%—75% 1RM, however with a wider gap at 80%—85% 1RM. The NAL group, instead, did not presented such a detectable behaviour across the whole ST. Moreover, both groups demonstrated improved performances in PSQ, CMJ, and SJ, whereas there were little changes in 30S and 30F after ST. Additionally, AL obtained a greater effect size than NAL in PSQ (0.60 vs. 0.35) but lower effect size in CMJ, SJ, 30S, and 30F (0.41 vs. 0.63, 0.30 vs. 0.40, 0.04 vs. 0.28 and 0.22 vs. 0.24). However, percentage change was greater in AL in all tests.
Discussion: Based on these findings, we can conclude that further investigation into the AL strategy in VBT is warranted for sprinter athletes’ daily strength practices. The AL technique shows promise as a valuable tool for accurately adjusting and monitoring medium-high training loads to ensure they align with the intended intensity.
... In particular, the considerable experience of the subjects in performing both modalities of the SQ at full range of motion could have attenuated the longitudinal fascicle growth that usually occurs when training at lengths to which the muscle is not accustomed. 40 On the other hand, the low levels of intraset fatigue incurred by both modalities, which in turn have been demonstrated to generate noteworthy strength gains without considerable hypertrophy, 21 could explain the reduced incorporation of sarcomeres in parallel (iVL PA ). ...
Background
Although the superior effectiveness of free‐weight over machine‐based training has been a traditionally widespread assumption, longitudinal studies comparing these training modalities were scarce and heterogeneous.
Objective
This research used the velocity‐based method to compare the effects of free‐weight and machine‐based resistance training on athletic performance and muscle architecture.
Methods
Thirty‐four resistance‐trained men participated in an 8‐week resistance training program allocated into free‐weight (n = 17) or machine‐based (n = 17) groups. Training variables (intensity, intraset fatigue, and recovery) were identical for both groups, so they only differed in the use of a barbell or specific machines to execute the full squat, bench press, prone bench pull, and shoulder press exercises. The velocity‐based method was implemented to accurately adjust the planned intensity. Analysis of covariance and effect size (ES) statistics were used to compare both training modalities on a comprehensive set of athletic and muscle architecture parameters.
Results
No between‐group differences were found for any athletic (p ≥ 0.146) and muscle architecture (p ≥ 0.184) variable. Both training modalities significantly and similarly improved vertical jump (Free‐weight: ES ≥ 0.45, p ≤ 0.001; Machine‐based: ES ≥ 0.41, p ≤ 0.001) and lower limb anaerobic capacity (Free‐weight: ES ≥ 0.39, p ≤ 0.007; Machine‐based: ES ≥ 0.31, p ≤ 0.003). Additionally, the machine‐based group meaningfully enhanced upper limb anaerobic power (ES = 0.41, p = 0.021), whereas the free‐weight group significantly improved the change of direction (ES = ‐0.54, p = 0.003) and 2/6 balance conditions analyzed (p ≤ 0.012). Changes in sprint capacity (ES ≥ ‐0.13, p ≥ 0.274), fascicle length, and pennation angle (ES ≤ 0.19, p ≥ 0.129) were not significant for either training modality.
Conclusion
Adaptations in athletic performance and muscle architecture would not be meaningfully influenced by the resistance modality trained.
... This means that the performed additional repetition may be effective when aiming at muscle hypertrophy. Previous studies support the notion that with a greater velocity loss, muscle hypertrophy gains can be more significant (Pareja-Blanco et al., 2017), but only to some extent (Andersen et al., 2021;Pareja-Blanco et al., 2020). Evidence suggests that when velocity loss is excessive (40%), subsequent sets could be affected (Pareja-Blanco et al., 2020). ...
Post-Activation Performance Enhancement (PAPE) has been commonly used as a strategy to improve acute force production, although its effects on performance to volitional failure are still unknown. The aim of this study was to analyse the influence of a PAPE protocol on bench press performance in a training set to volitional failure in trained individuals. Fourteen participants with at least two years of resistance training experience (age 24.57 ± 2.7 years; body mass 77.47 ± 12.2 kg; body height 174.21 ± 7.4 cm; medium grip bench press 1 repetition maximum (1RM): 101.6 ± 25.8 kg), of which 14 completed the control protocol and 12 completed the experimental protocol, took part in the study. After a standardised warm-up, participants completed three sessions: 1) a 1RM test for the medium grip bench press, 2) a control condition consisting of a set of the bench press to volitional failure with 80% 1RM (CON), and 3) an experimental condition consisting of a set of the bench press to volitional failure with 80% 1RM after a PAPE protocol (PAPE). The PAPE protocol consisted of a heavy set of one repetition with their 93% 1RM as the conditioning activity. Under the PAPE condition, participants performed significantly more repetitions than under the CON condition (p = 0.008, ES = 0.5, small effect), their last repetition was slower (p = 0.02, ES = 0.52, small effect) and presented a higher velocity loss (p = 0.004, ES = 0.75, moderate effect). These results suggest that a traditional PAPE protocol improves the number of repetitions performed to volitional failure.
... This way of prescribing the relative load has the advantage of knowing in real-time whether the participant is training according to the programmed relative load and adjusting the absolute load if large deviations from the target velocity are observed [12-14, 50, 51]. Indeed, prescribing the relative loads based on specific velocities instead of percentages of 1RM has increased in the last few years in research and training settings with younger populations [14,[50][51][52][53]. However, these procedures have never been performed in geriatric settings, which means that future studies using a velocity-monitored resistance training approach should be conducted to test its feasibility in older adults. ...
AimThis study aimed to i) determine the load-velocity relationship in the seated chest press in older adults, ii) compare the magnitude of the relationship between peak and mean velocity with the relative load, and iii) analyze the differences between sexes in movement velocity for each relative load in the chest press.Material and methodsThirty-two older adults (17 women and 15 men; 79.6±7.7 years) performed a chest press progressive loading test up to the one-repetition maximum (1RM). The fastest peak and mean velocity reached with each weight were analyzed. Quadratic equations were developed for both sexes and the effectiveness of the regression model was analyzed through a residual analysis. The equations were cross-validated, considering the holdout method. The independent samples t-test analyzed i) the differences in the magnitude of the relationship between peak and mean velocity with the relative load and ii) the differences between sexes in the peak and mean velocity for each relative load.ResultsIt was possible to observe very strong quadratic load-velocity relationships in the seated chest press in women (peak velocity: r2 = 0.97, standard error of the estimate (SEE) = 4.5% 1RM; mean velocity: r2 = 0.96, SEE = 5.3% 1RM) and men (peak velocity: r2 = 0.98, SEE = 3.8% 1RM; mean velocity: r2 = 0.98, SEE = 3.8% 1RM) without differences (p>0.05) in the magnitude of the relationship between peak and mean velocity with the relative load. Furthermore, there was no overfitting in the regression models due to the high and positive correlation coefficients (r = 0.98-0.99). Finally, men presented higher (p0.05).Conclusion
Measuring repetition velocity during the seated chest press is an objective approach to estimating the relative load in older adults. Furthermore, given the velocity differences between older women and men at submaximal loads, it is recommended to use sex-specific equations to estimate and prescribe the relative loads in older adults.
... Muscle fatigue is an example of physical fatigue characterized by a temporary reduction in strength and skeletal muscle power capacity that results from muscle activity (Wan et al., 2017). This phenomenon typically occurs in athletes due to routine endurance training (Pareja-Blanco et al., 2017) and in individuals engaged in prolonged, strenuous activities, such as hospital porters (Escriche-Escuder et al., 2020). ...
The use of natural or conventional-based supplementation has become a popular strategy among athletes seeking to reduce oxidative stress, improve recovery, and enhance athletic performance. This literature review searched four reputable international electronic databases, including PubMed, MedRxiv, Cochrane, and Clinical Trial.gov until December 2021, using Boolean operators with keywords and Mesh methods. The keywords used were "Supplementation", AND "Muscle Fatigue Recovery", AND "Athletes", which yielded 24 articles as study findings. The literature review found that exhaustive exercise can induce a neutrophil antioxidant response by increasing antioxidant enzymes. Nutritional supplements, specifically antioxidant supplements, Branched Chain Amino Acid (BCAA), citrulline, omega-3, and caffeine, have been scientifically proven to reduce oxidative damage, which can block signaling pathways related to muscle hypertrophy. In order to combat muscle fatigue in athletes based on this research (literature review), natural ingredients and synthetic nutritional supplements have been utilized as dietary interventions. This literature review identified numerous natural micronutrients and synthetic supplements used in sports that possess anti-fatigue properties, decrease oxidative stress and enhance athletes' endurance capacity. The effectiveness of nutritional supplements in addressing muscle fatigue may vary based on the various ingredients in the supplements. However, natural-based supplements have become a preferred option among athletes and coaches currently.
... This alternative approach offers a way to improve training outcomes. Pareja-Blanco et al., 2017;Galiano et al., 2022;Pareja-blanco et al., 2020;Weakley et al., 2020a). The use of velocity loss thresholds between 5-20% allows for lower total training volumes compared to traditional resistance training routines, enabling better recovery both within and between sessions, without compromising neuromuscular adaptations, although gains in hypertrophy were more pronounced when higher velocity loss thresholds were applied (Baena-Marín et al., 2022;Włodarczyk et al., 2021;Weakley et al., 2020bWeakley et al., , 2021b. ...
The aim of this study was to verify the concurrent validity and the biological error-free reliability of a novel low-cost commercial encoder (Ergonauta I). Validity protocol involved comparisons with a custom system and other encoder commercially available (Vitruve). Reliability protocols involved inter devices and inter unit comparisons. No participants were recruited, and reliability assessments were performed in a Smith Machine by bar free fall tests. Our results showed a significant bias for mean velocity (MV) estimated by both encoders only in one of the four conditions investigated (bias=0.05 m/s). Regarding sensitivity, the smallest detectable change suggests only values higher than 0.03 m/s must to be considered as real changes in performance, when monitoring MV and mean propulsive velocity (MPV) through Ergonauta I and Vitruve. Between-days intra-device reliability showed Ergonauta I remains highly reliable after one week for most assessments, whereas slightly less sensitive for peak velocity and peak power output.
... s -1 as this is, on average, ending a set at a 2RIR . Additionally, a velocity loss prescription could be used, such as 4 sets, with each being terminated when a specific velocity loss threshold (e.g., 10, 20, 30, or 40% of the first repetition) has been reached (Galiano et al., 2020;Pareja-Blanco et al., 2017;Rodiles-Guerrero et al., 2022;Weakley et al., 2020). However, VBT programming has limitations of its own. ...
The purpose of this investigation was to determine if average concentric velocity (ACV) of a single repetition at 70% of one-repetition maximum (1RM), ACV of the first repetition of a set to failure at 70% of 1RM, or the velocity loss during the set could predict the number of repetitions performed in the back squat. Fifty-six resistance-trained individuals participated in the study (male = 41, age = 23 ± 3 yrs, 1RM = 162.0 ± 40.0 kg; female = 15, age = 21 ± 2 yrs, 1RM = 81.5 ± 12.5 kg). After 1RM testing, participants performed single repetition sets with 70% of 1RM and a set to failure with 70% of 1RM. ACV was recorded on all repetitions. Regression model comparisons were performed, and Akaike Information Criteria (AIC) and Standard Error of the Estimate (SEE) were calculated to determine the best model. Neither single repetition ACV at 70% of 1RM (R² = 0.004, p = 0.637) nor velocity loss (R² = 0.011, p = 0.445) were predictive of total repetitions performed in the set to failure. The simple quadratic model using the first repetition of the set to failure () was identified as the best and most parsimonious model (R2 = 0.259, F = 9.247, p < 0.001) due to the lowest AIC value (311.086). A SEE of 2.21 repetitions was identified with this model. This average error of ~2 repetitions warrants only cautious utilization of this method to predict total repetitions an individual can perform in a set, with additional autoregulatory or individualization strategies being necessary to finalize the training prescription.
... In strength training, the measurement of barbell velocity during different exercises (i.e., bench press, squat, power clean) has become a contemporary approach to control strength training (i.e., velocity based training [VBT]) (Weakley et al., 2021). VBT has been used in several strength training related contexts, such as, estimating one-repetition maximum (1RM) Jukic et al., 2020), describing and adjusting training intensity (Jiménez-Reyes et al., 2021;Suchomel et al., 2021), or monitoring and controlling training-induced fatigue (Hughes, Banyard, Dempsey, Peiffer, et al., 2019;Pareja-Blanco et al., 2017). Although VBT is becoming very popular in the last decade, the concept itself is not new. ...
Measurement of barbell velocity is a simple and effective way to control strength training. To assess the concurrent validity of different technological approaches measuring barbell velocity, video-analysis (Kinovea), linear velocity transducer (Speedograph), and an inertial measurement unit (VmaxPro) were compared. Sixty-eight female and male sport science students lifted two repetitions in the bench press exercise at self-selected barbell loads. Peak vertical barbell velocity (Vmax) was parallel measured during the concentric phase of the lift using the aforementioned devices. Concordance correlation coefficient (CCC), Deming regression (DR) and Bland-Altman analysis (BA) were used to assess relative and absolute concurrent validity of Vmax measured with Kinovea, Speedograph, and VmaxPro. Results confirmed high concurrent validity of Speedograph and VmaxPro (CCC = 0.99, standard deviation of differences [SDD] = 0.04 m•s-1) without detecting proportional or constant bias. In contrast, Vmax measured with Kinovea showed poor concurrent validity to Speedograph (CCC = 0.83) and VmaxPro (CCC = 0.81) with significant proportional and constant bias. Regression based re-calibration of Vmax from Kinovea resulted in an SDD = 0.09 m•s-1 compared to Speedograph and an SDD = 0.08 m•s-1 compared to VmaxPro. Among the three tested devices, Vmax assessed using Kinovea showed poor concurrent validity. Furthermore, as Kinovea showed proportional bias compared to Speedograph and VmaxPro, application-specific re-calibration of Kinovea should be applied when barbell velocity data is compared to Speedograph and VmaxPro.
... We must acknowledge some limitations. Considering that a linear encoder provides the mean propulsive velocity (Pareja-Blanco et al., 2017) and that the minimum mean propulsive velocity for a successful lift in the bench press has been calculated (González-Badillo et al., 2011), more velocity implies more distance from that mean minimum propulsive velocity, and thus, furthers subjects failure. Unfortunately, changes in magnitude (e.g., from 0.27 m·s -1 to 0.29 m·s -1 ) were so small that statistical significance was not reached. ...
During the last years, post-activation performance enhancement (PAPE) has gained notorious popularity due to the capacity to improve the acute rate of force development (RFD) using different strategies with different muscle contraction regimes as conditioning stimuli. The aim of the present study was to analyse the role of a maximal isometric post-activation performance enhancement (PAPE) protocol in performance and its effects on the kinematics of the sticking region. Twenty-one trained participants (age 26.4 ± 5.4 years) underwent two experimental sessions: an experimental session consisting of a single set and a single repetition of the bench press at the 93% of 1RM (which is considered a traditional conditioning activity to induce PAPE) (TRAD) and an isometric experimental session (ISO) consisting of 15 maximal voluntary isometric contractions in the sticking region of the medium grip bench press lasting 1 s with a 1 s rest interval between contractions. Both TRAD and ISO experimental conditions improved performance from post0 to post4, post8, post12 and post16, but only the ISO condition improved performance from the start of the lift to the start of the sticking region from pre to post (p < 0.001), and only the ISO condition improved maximum (p = 0.005) and minimum (p = 0.025) peak velocities. The results of this study suggest that short duration maximal voluntary isometric contractions improve the velocity of the lift prior to the initiation of the sticking region, which ultimately improves the impulse and facilitates the lift.
... Statistica v.7.0 (StatSoftInc) was used to process the received data. The methods of mathematical statistics (dispersion analysis) were applied [23]. The creative thinking, motor, and in-game variables were log-transformed and the minimum difference was defined as 0.2 among participants' standard deviations. ...
span lang="EN-US">Supporting students’ physical development and creativity under the influence of modern globalization is one of the key tasks for today’s science community. The present study aims to develop an individual program of physical and creative development in first- and second-year female students, taking account of their educational and anthropometric characteristics. Students’ level of creative thinking was assessed according to William’s methodology, and a physical education program for experimental group respondents was developed to link the two factors. Consequently, the program’s implementation demonstrated significant changes in the respondents’ creative thinking towards a positive gradation. The number of respondents with low creative thinking scores in the primary follow-up survey increased to an average of 120 students. At the same time, the Chi-square analysis to compare the experimental and control sample in detail indicates that experimental and control sample designs are consistent (χ2 = 122.77). This study may be used in more in-depth research on the interrelationships between youth’s physical and creative development. Besides, it can also serve as a prototype for implementing associated integrated student development programs at the university.</span
... It is also likely that the proximity-to-failure reached by participants in non-failure conditions varies considerably within-and between-studies due to commonly employed predetermined repetition prescriptions and individual variability in the maximum number of repetitions possible with a given load [8][9][10]. Some studies have attempted to address this research limitation by employing 'velocity loss' thresholds to control and standardise set termination; however, even the magnitude of velocity loss achieved during a given set cannot accurately inform proximity-to-failure during RT [1] as evidenced by one study that found participants who performed the squat exercise until 40% velocity loss reached momentary muscular failure ~ 56% of the time [11]. As such, although mechanical and metabolic indicators of neuromuscular fatigue increase with the magnitude of velocity loss achieved [12][13][14], the proximity-to-failure reached across velocity loss conditions is unknown and likely varies. ...
Background:
This study examined the influence of proximity-to-failure in resistance training (RT), using subjective repetitions-in-reserve (RIR) prediction, on neuromuscular fatigue and perceptual responses.
Methods:
Twenty-four resistance-trained males (n = 12) and females (n = 12) completed three experimental trials in a randomised order, each involving six RT sets (barbell bench press) with 75% 1-RM performed to either momentary muscular failure (FAIL), 1-RIR, or 3-RIR. Changes in lifting velocity with a fixed load were assessed from pre-exercise to post-exercise with the aim of quantifying acute neuromuscular fatigue (4 min post-exercise) and the associated time course of recovery (24 and 48 h post-exercise), and from the first to final set performed. Perceptual responses to RT were assessed at multiple time points during and following RT.
Results:
Decreases in lifting velocity at 4 min post-exercise were greater for FAIL ( - 25%) versus 1-RIR ( - 13%) and 3-RIR ( - 8%), with greater decreases for male ( - 29%) versus female ( - 21%) participants following FAIL. At 24 h post-exercise, decreases in lifting velocity were greater for FAIL ( - 3%) and 1-RIR ( - 3%) versus 3-RIR (+ 2%), with all between-protocol differences diminishing at 48 h post-exercise. Loss of lifting velocity from the first to final set was greater for FAIL ( - 22%) versus 1-RIR ( - 9%) and 3-RIR ( - 6%), with a greater lifting velocity loss from the first to final set for males ( - 15%) versus females ( - 9%). As proximity-to-failure neared, ratings of perceived discomfort, exertion, and muscle soreness increased, general feelings worsened, and perceived recovery decreased.
Conclusion:
These findings support a linear relationship between RT proximity-to-failure and both acute neuromuscular fatigue and negative perceptual responses, which may influence long-term physiological adaptations and adherence to RT.
... These results are similar to those found in other studies where an MPTP was developed [68][69][70]. Although the studies mentioned above present a program design similar to the present research, this study has the advantage of developing work with a medium to low effort character (EC) and a lower total number of repetitions per series, which could be translated into an improvement in the quality of training [71], a complete recovery between sets and training sessions, and a decreased risk of injury [72], as evidenced throughout the training program. In addition, the gradual incorporation of strength, cardiovascular resistance, balance, and flexibility work by phases and progressive blocks, allowed the gradual development of functional capacity to perform sessions of longer duration and with greater variety of activities with better performance compared to conventional multicomponent training, which focuses on the development of all physical qualities in a single session [73]. ...
Objective:
To evaluate the effect of a multicomponent progressive training program (MPTP) on functionality, quality of life (QoL) and motivation to exercise (EM) in a group of older adults (OA) of a community.
Methods:
A total of 55 participants of 69.42 ± 6.01 years of age were randomized into two groups; experimental (EG:35) and control (CG:20), and subjected to 27 weeks of MPTP. Functionality (pre/post-intervention) was assessed using the Short Physical Performance Battery (SPPB), Time Up and Go (TUG), Walking While Talking Test (WWT), Manual Dynamometry (MD), Forced Expiratory Volume in the first second (FEV1), Sit and Reach (SR), Back Scratch (BS), and walk for 2 min (2 mST). QoL was assessed using the SF-36 questionnaire and EM using the BREQ-3. The Kolmogorov-Smirnov and Levene tests were applied. A two-way repeated measures ANOVA was applied. A significance level of p < 0.05 was accepted for all comparisons.
Results:
The EG compared to the CG improved in SPPB (ΔEG/CG: 29.67%/p < 0.001), TUG (ΔEG/CG: 35.70%/p < 0.05), WWT (ΔEG/CG: 42.93%/p < 0.001), MD (ΔEG/CG: 20.40%/p < 0.05), FEV1 (ΔEG/CG: 21.37%/p < 0.05), BS (ΔEG/CG: 80.34%/p < 0.05), 2 mST (ΔEG/CG: 33.02%/p < 0.05), SF-36 (ΔEG/CG: 13.85%/p < 0.001), and Intrinsic Regulation (ΔEG/CG: 27.97%/p < 0.001); Identified by regulation (ΔEG/CG: 9.29%/p < 0.05).
Conclusion:
An MPTP improves functionality, QoL and EM, and is a safe and effective method for community OAs.
... In physiological theories, changes in any athletic performance can be explained by the physiological adaptations induced by training stimulations [47,48]. Pareja-Blanco, et al. [44] found that VBT with a high velocity loss increased the cross-sectional area of slowtwitch fibers, suggesting a negative impact on maximum strength development. A recent review suggests that the velocity loss of VBT is negatively associated with the IIX (MHC-IIX) percentage and is positively associated with the myosin heavy chain I (MHC-I) percentage [9], which may explain the selective hypertrophy of skeletal muscles in VBT. ...
The velocity loss method is often used in velocity–based training (VBT) to dynamically regulate training loads. However, the effects of velocity loss on maximum strength development and training efficiency are still unclear. Therefore, we conducted a dose–response meta–analysis aiming to fill this research gap. A systematic literature search was performed to identify studies on VBT with the velocity loss method via PubMed, Web of Science, Embase, EBSCO, and Cochrane. Controlled trials that compared the effects of different velocity losses on maximum strength were considered. One–repetition maximum (1RM) gain and 1RM gain per repetition were the selected outcomes to indicate the maximum strength development and its training efficiency. Eventually, nine studies with a total of 336 trained males (training experience/history ≥ 1 year) were included for analysis. We found a non–linear dose–response relationship (reverse U–shaped) between velocity loss and 1RM gain (p dose–response relationship < 0.05, p non–linear relationship < 0.05). Additionally, a negative linear dose–response relationship was observed between velocity loss and 1RM gain per repetition (p dose–response relationship < 0.05, p non–linear relationship = 0.23). Based on our findings, a velocity loss between 20 and 30% may be beneficial for maximum strength development, and a lower velocity loss may be more efficient for developing and maintaining maximum strength. Future research is warranted to focus on female athletes and the interaction of other parameters.
... This test has been validated in different populations, regardless of sex or age. The protocol used was performed according to that proposed by Pareja-Blanco et al. [21]. The MPV was measured using a linear position transducer (Speed4Lifts™, Madrid, Spain), which was installed on the bar with which the 1RM was measured. ...
Sport is a science of constant reinvention that is always searching for strategies to improve performance. Objective: This study seeks to compare the effects of myofascial release with Findings-Oriented Orthopedic Manual Therapy (OMT) combined with Foam Roller (FR), versus FR by itself, on the physical performance of university athletes. A randomized controlled study was conducted with a total of twenty-nine university athletes, measuring Range of Motion (ROM), jump height and flight time, strength and dynamic flexibility using Goniometer pro, CMJ protocol in OptoGait, 1 Repetition Maximum (1RM) and Mean Propulsive Velocity (MPV) and the Sit and Reach (V) test, correspondingly. This study was registered at clinicaltrials.gov prior to the initial measurement of the participants under the code NCT05347303. Through a univariate analysis, together with an analysis of independent groups with ANOVA and an analysis of covariance, it was evidenced that OMT combined with FR generated more and better effects in all the evaluated ROM, jump height and flight time, RM and VMP tests. Finally, it was found that OMT combined with FR is better when it is desired to improve ROM, muscle power, strength and flexibility, while FR alone only improves dynamic flexibility.
... It also compared the lifting load with individual baseline 1RM based on the corresponding movement velocity under the heavy load (back squat 0.38 ± 0.05 m/s, bench press 0.32 ± 0.05 m/s). The above comparative analyses were ignored in previous studies (Pareja-Blanco et al., 2017;Dorrell et al., 2020;Jukic et al., 2022). These results provide support for the hypothesis that the lifted load weight of VBRT was higher than it is designed by percentage-based resistance training. ...
Introduction: The study compared the effects of 6-week (2 sessions/week) velocity-based resistance training (VBRT) and percentage-based resistance training (PBRT) on athletic performance in Sport-College female basketball players. Methods: Fifteen participants were assigned to the VBRT (n = 8) or PBRT (n = 7) groups. The load in VBRT group were determined through the sessional target velocity and velocity loss monitoring, whereas PBRT group used a fixed-load based on percentage of 1-repetition maximum (1RM). Both groups completed intervention that involved the free weight back squat and bench press using the same relative load (linear periodization from 65% to 95% 1RM). Training loads data was continuously recorded. Measurements at baseline (T0) and post-training (T2) included 1RM, countermovement-jump (CMJ), squat-jump (SJ), eccentric-utilization-ratio (EUR), drop-jump height and reactive-strength-index (DJ, DJ-RSI), plyometric-push-up (PPU), 505 change-of-direction (COD), 10-m、20-m sprint (T-10、T-20), 17 × 15 m drill-lines (17-drill), Hexagon agility, and functional movement screen (FMS). A mid-term (T1) assessment was included to investigate the short-term effects of both methods and the fluctuation of personalized 1RM. Results: No between-group differences were observed at T0 for descriptive variables (p > 0.05). Both groups showed significant improvement in strength gains for back squat and bench press, but VBRT showed likely to very likely favorable improvements in CMJ, SJ, EUR, DJ-RSI, Hexagon and COD among athletic performance. The VBRT showed likely to very likely improvements in 17-drill and DJ, while PBRT showed unclear effects. The lifted weights adjusted by VBRT method were higher than prescribed by PBRT (p < 0.05) for the same subjects. Conclusion: Compared with fixed-load PBRT, VBRT enhanced power and athletic performance despite similar strength gains. VBRT can be regarded as a more functional resistance-training method under linear periodization.
... Resistance training is proven to increase lean body mass, strength, and power (ie hypertrophy). Nevertheless, it was found that it can enhance physical performance (such as jump height), which can support sporting outcomes [1]. However, many people practice resistance exercises because of their effectiveness in increasing muscle mass and strength [2]. ...
Background and Study Aim. To compare the effects of three different sets method, which is frequently used in resistance training, on strength and hypertrophy values.
Materials and Methods. Thirty-three young male athletes with similar daily activities and nutrient intakes at the Fitlife fitness center in Sakarya were included in the study. Participants were randomly divided into three different groups as Modified German Volume Training (MGVT) (n=11, 21.5 ± 2.4 years), Super Set (SS) (n=11, 22.4 ± 2.9) and Giant Set (GS) (n=11, 23.0 ± 4.3 years). The study was started with a total of thirty-three people, but two participants in the Giant set group were excluded from the measurements because they left the study due to personal reasons. Strength, muscle thickness and cross-sectional area (CSA) measurements were made in the upper extremity muscles before and after the six-week training period.
Results. After six weeks of training, significant increases were observed in the cross-sectional area and thickness (p
... trabajando con un 60 % menos de volumen total. (Hickmott, L.M., et al. 2022;Pareja-Blanco F. et al. 2017). ...
En este libro,bajo un enfoque critico revisionista, se abordan temas relacinados con la planificacion y los componentes de la magnitud de la carga del entrenamiento para el fitness y el deporte de rendimiento.
Se proponen guias generales para el entrenamiento de la fuerza; la velocidad, rapidez y agilidad; la resistencia; la movilidad; y la estabilidad.
... Thanks to the advancement and proliferation of sports technology (20,29), the recording of lifting velocity has recently been proposed as an objective and accurate tool for prescribing the number of repetitions contained within a training set (27). Although it should be noted that there are different approaches for prescribing the number of repetitions based on velocity measurements (1,4), the real-time monitoring of the velocity loss (i.e., percent difference in velocity between the fastest and last repetition of the set; %VL) incurred in a set is the approach most commonly reported in the scientific literature (16,17,28). It has been reported that the %VL incurred in a set is strongly related to metabolic and mechanical measures of fatigue (e.g., blood lactate and ammonia concentration or countermovement jump height loss) (23,28). ...
The primary aim of this study was to explore the goodness-of-fit and accuracy of both general and individual relationships between the magnitude of velocity loss (%VL) and the percentage of performed repetitions with respect to the maximal number of repetitions that can be completed to failure (%Rep) during the Smith machine prone bench pull exercise. Fifteen male sports science students completed a preliminary session to determine the bench pull one-repetition maximum (1RM) and two identical experimental sessions separated by 48-72 hours. In each experimental session subjects randomly performed single sets of repetitions to failure separated by 10 minutes against the 60%1RM, 70%1RM, and 80%1RM during the Smith machine bench pull exercise. Individual %Rep-%VL relationships presented a greater goodness-of-fit than general %Rep-%VL relationships at the 60%1RM (R2 = 0.85-0.97 vs. 0.79-0.85), 70%1RM (R2 = 0.84-0.99 vs. 0.77-0.84), and 80%1RM (R2 = 0.84-1.00 vs. 0.74-0.80). However, the accuracy (absolute errors) in estimating the %Rep during the second testing session based on the %Rep-%VL equations obtained in the first testing session did not differ between the individual and general %Rep-%VL equations in 8 out of 9 comparisons (P ≥ 0.102). The absolute errors between the actual and predicted %REP were unacceptable (> 10%) in 11 out of 18 comparisons, and acceptable (5-10%) in 7 out of 18 comparisons. These results highlight that, regardless of whether individual or general Rep-%VL relationships are considered, the %Rep cannot be estimated with high degree of accuracy from VL recordings during the Smith machine bench pull exercise.
Training process in elite padel players is influenced by travels and competitions density. The irregularity in the workloads, as well as demands of the season, could affect the musculoskeletal structures. Strength training has a protective role against the injury incidence, but the competitive context does not always allow adequate periodization of training and thus achieve adaptations. The aim of this study is to analyze, using technological tools, if improvements in player’s fitness are accompanied by improvements in sport performance through a case study. An elite padel player was analyzed during the 2021 season. Physical fitness was evaluated using different technological tools. Athlete monitoring was carried out using self-reported forms and sport performance was assessed through the results obtained in the World Padel Tour ranking at the end of the season. During the training process, multidimensional training was carried out in order to achieve the maximum availability of specific loads through coadjuvant training. Results of the assessment show slight improvements in all fitness tests. Assessment of sport performance reports an increased number of victories and a better position in the professional ranking. Musculoskeletal improvements helped the athlete’s workload tolerance, allowing overall improvement in padel performance. The training approach from this study has shown to be effective in maintaining or even improving force-producing capacity in lower and upper limbs, force-velocity relationship, agility and sport performance, despite the high competitive density. This work provides coaches with a practical approach to assess, monitor and design a competitive season for an elite padel player.
Velocity-based training (VBT) is an increasingly popular programming strategy used by strength and conditioning professionals to develop their athlete's ability to express force rapidly. To implement the varying forms of VBT effectively within their training regimes, strength and conditioning professionals need to understand the strengths and weaknesses of strategies, such as predicting 1 repetition maximum using the load-velocity profile, modulating training loads using the load-velocity profile, and controlling training volume using the magnitude of velocity-loss. The aim of this review was to highlight these strengths and weaknesses and then provide practical examples of when each programming strategy may be most effectively implemented.
Geschwindigkeitsbasiertes Krafttraining verbessert die Sprung-, Spring- und Kraftleistung. Die Autoren haben verschiedene Studien miteinander verglichen, um herauszufinden, ob die Trainingseffekte hierbei besser sind als bei traditionellem Krafttraining.
Objectives
Jumping ability has been identified as a key factor that influences the performance of badminton athletes. Autoregulatory progressive resistance exercise (APRE) and velocity-based resistance training (VBRT) are commonly used approaches to enhance muscle strength and have been shown to accurately monitor the development of explosive power to improve jumping ability. This study aims to investigate the effects of APRE and VBRT on badminton athletes’ jumping ability and to provide practical insights into improving their jumping performance during competitions.
Methods
Upon completing familiarization and pretesting, 18 badminton athletes were included and completed the training intervention (age, 21.4 ± 1.4 years; stature, 170.1 ± 7.3 cm; body mass, 65.9 ± 12 kg); they were randomly divided into the APRE group ( n = 9) and VBRT group ( n = 9). Jumping performance was assessed during the countermovement jump (CMJ), squat jump (SJ), and drop jump (DJ) via SmartJump, with CMJ ’s and SJ’s jump height, eccentric utilization ratio (EUR), and reactive strength index (RSI). All participants then completed a 4-week in-season resistance training intervention.
Results
(1) The results of the within-group indicated that only the CMJ (pre: 41.56 ± 7.84 vs post: 43.57 ± 7.85, p < 0.05) of the APRE group had significant differences, whereas the SJ, EUR, and RSI were not significantly different ( p > 0.05). (2) The results of the intergroups revealed that all indicators had no significant differences ( p > 0.05), but APRE had a moderate effect size on the improvement of the CMJ ( η ² = 0.244) and EUR ( η ² = 0.068) when compared with VBRT.
Conclusions
The results showed that, compared to VBRT, APRE can effectively improve the performance of the reactive athletes’ lower limb explosive power in the CMJ in a shorter period of time. The findings indicate that APRE may be useful for coaches seeking to improve the CMJ performance of athletes in the short term.
Meta-analysis, Resistance training, Dose-response.
El objetivo fue evaluar los efectos de un entrenamiento multicomponente en fases progresivas de 18 semanas sobre la autonomía funcional, el rendimiento físico y la calidad de vida en mujeres mayores de la comunidad. La muestra fue de 73 mujeres con una media de edad de 69.81±9.44 años. Para evaluar la autonomía funcional se utilizó el protocolo GDLAM. El rendimiento físico fue evaluado mediante las pruebas de velocidad de marcha en 10 metros, flexo-extensiones de codo con mancuerna, dinamometría manual, levantarse de la silla durante 30 segundos, sit and reach y back scracth. La calidad de vida se evaluó mediante el cuestionario SF-36. Al finalizar la intervención, se observaron mejoras en la autonomía funcional (p<0,001), el rendimiento físico (p<0,001) y la calidad de vida (p<0,001). En conclusión, un entrenamiento multicomponente en fases progresivas mejora la autonomía funcional, el rendimiento físico y la calidad de vida, siendo un método seguro y eficaz para las mujeres mayores de la comunidad.
Velocity-based training is an advanced auto-regulation method that uses objective indices to dynamically regulate training loads. However, how to maximize muscle strength with appropriate velocity-based training settings is yet unclear. To fill this gap, we conducted a series of dose-response and subgroup meta-analyses to check the effects of training variables/parameters (including intensity, velocity loss, set, inter-set rest intervals, frequency, period, and program) on muscle strength in velocity-based training. A systematic literature search was performed to identify studies via PubMed, Web of Science, Embase, EBSCO, and Cochrane. One repetition maximum was selected as the outcome to indicate muscle strength. Eventually, twenty-seven studies with 693 trained individuals were included in the analysis. We found that the velocity loss of 15 to 30%, the intensity of 70 to 80%1RM, the set of 3 to 5 per session, the inter-set rest interval of 2 to 4 min, and the period of 7 to 12 weeks could be appropriate settings for developing muscle strength. Three periodical programming models in velocity-based training, including linear programming, undulating programming, and constant programming, were effective for developing muscle strength. Besides, changing periodical programming models around every 9 weeks may help to avoid a training plateau in strength adaption.
The purpose of this study was to identify
changes in neuromuscular performance variables evaluated through the countermovement jump test before and
after (0 hours, after session and 24h post) of a simulated futsal protocol in young university female athletes.
Fourteen eumenorrheic, healthy and experienced female futsal players were randomly assigned to an intervention
group n = 7) or a control group (n = 7). Both groups performed three countermovement jumps before and after the
protocol using an inertial system device. The intervention group completed a short-term functional agility and
fatigue protocol that simulated the characteristics of futsal, while the control group did not perform any exercise.
The results showed a reduction in peak flight time (p = 0.049; d = 0.586), peak concentric work (p = 0.03; d = 1.819)
and peak maximum force (p = 0.02; d = 0.782) comparing experimental and control group. No changes in other
variables examined were noted between conditions (p > 0.05). These findings indicate that the changes in
neuromuscular performance variables, evaluated through a simulated protocol, are established as determinants in
the definition of peripheral fatigue in futsal practitioners until 24 h after a demanding intervention.
Humans are unique among terrestrial mammals in our manner of walking and running, reflecting 7 to 8 Ma of musculoskeletal evolution since diverging with the genus Pan. One component of this is a shift in our skeletal muscle biology towards a predominance of myosin heavy chain (MyHC) I isoforms (i.e. slow fibers) across our pelvis and lower limbs, which distinguishes us from chimpanzees. Here, new MyHC data from 35 pelvis and hind limb muscles of a Western gorilla (Gorilla gorilla) are presented. These data are combined with a similar chimpanzee dataset to assess the MyHC I content of humans in comparison to African apes (chimpanzees and gorillas) and other terrestrial mammals. The responsiveness of human skeletal muscle to behavioral interventions is also compared to the human-African ape differential. Humans are distinct from African apes and among a small group of terrestrial mammals whose pelvis and hind/lower limb muscle is slow fiber dominant, on average. Behavioral interventions, including immobilization, bed rest, spaceflight and exercise, can induce modest decreases and increases in human MyHC I content (i.e. -9.3% to 2.3%, n = 2033 subjects), but these shifts are much smaller than the mean human-African ape differential (i.e. 31%). Taken together, these results indicate muscle fiber content is likely an evolvable trait under selection in the hominin lineage. As such, we highlight potential targets of selection in the genome (e.g. regions that regulate MyHC content) that may play an important role in hominin skeletal muscle evolution.
Background
To promote chronic adaptations, resistance training needs the manipulation of different variables, among them, the order of the exercises and sets. Specifically, for velocity-based training, paired exercises alternating upper and/or lower-body muscle groups appear to be a good choice to promote neuromuscular adaptations.
Objective
This study aimed to compare the effect of two velocity-based training programs only differing in the set configuration on muscle strength, muscular endurance and jump performance.
Methods
Moderately strength-trained men were allocated into a traditional (TS, n= 8) or alternating sets (AS, n= 9) configuration group to perform a 6-week velocity-based training program using the full squat (SQ) and bench press (BP) exercises. The TS group completed all sets of the full squat (SQ) exercise before performing the bench press (BP) sets, whereas the AS group completed the first set of each exercise in an alternating manner. Training frequency, relative load, number of sets, percentage of velocity loss (%VL) within the set and inter-set rest were matched for both groups. Countermovement jump height (CMJ), load (kg)-velocity relationship, predicted 1RM, and muscular endurance for each exercise were evaluated at pre- and post-training.
Results
The TS and AS groups obtained similar and non-significant improvements in CMJ (3.01 ± 4.84% and 3.77 ± 6.12%, respectively). Both groups exhibited significant and similar increases in muscle strength variables in SQ (6.19–11.55% vs. 6.90-011.76%; p = 0.033–0.044, for TS and AS, respectively), BP (6.19–13.87% and 3.99–9.58%; p = 0.036–0.049, for TS and AS group, respectively), and muscular endurance in BP (7.29 ± 7.76% and 7.72 ± 9.73%; p = 0.033, for the TS and AS group, respectively). However, the AS group showed a greater improvement in muscular endurance in SQ than the TS group (10.19 ± 15.23% vs. 2.76 ± 7.39%; p = 0.047, respectively). Total training time per session was significantly shorter ( p = 0.000) for AS compared to TS group.
Conclusions
Training programs performing AS between SQ and BP exercises with moderate loads and %VL induce similar jump and strength improvements, but in a more time-efficient manner, than the traditional approach.
La implementación de ejercicios de fuerza y velocidad en deportes como el béisbol, requiere de entrenamiento de la potencia: importante herramienta para realizar el impulso horizontal necesario para acelerar hacia adelante, y aplicable para maximizar el rendimiento en los jugadores. En atención a la demanda de esta capacidad, se reconoce como objetivo del presente estudio: diseñar un entrenamiento integrado de fuerza-velocidad en función del robo de segunda base en el béisbol. Se planifica la comprobación bajo la definición de dos grupos grupo: control y experimental, en dos momentos: pre y post test. La etapa experimental se desarrolla durante la pretemporada, conformada por una muestra de 20 jugadores con 20.84 años de edad y 79.82 kg de peso promedio. Se emplearon como métodos teóricos: el analítico-sintético, inductivo-deductivo, histórico-lógico, sistémico-estructural-funcional y como empíricos el análisis de contenido, la observación, la medición. Para la medición de la velocidad lineal las variables analizadas fueron el test de 30 yardas y los test de fuerza máxima de squat. Los resultados alcanzados indicaron mejoras significativas en el grupo experimental en los dos test realizados, con porcientos de incrementos iguales a 3.48 y 7.46 respectivamente. No se apreciaron diferencias significativas entre los resultados alcanzados en el pre y el post test del grupo control, el cual realizó un entrenamiento propio del béisbol. Se demuestra que el entrenamiento de ejercicio pliométrico de moderada intensidad sustentado sobre la base de ejercicios de squat, utilizándose el método de entrenamiento no fatigante, propicia una mayor aceleración de sprint en el béisbol. Abstract The implementation of strength and speed exercises in sports such as baseball, which require power training as a fundamental tool to perform the horizontal impulse necessary to accelerate forward and thus maximize performance in players. In response to the demand for this capacity, it is recognized as the objective of this study to design
International Journal of Exercise Science 16(1): 205-216, 2023. The purpose of this study was to identify changes in neuromuscular performance variables evaluated through the countermovement jump test before and after (0 hours, after session and 24h post) of a simulated futsal protocol in young university female athletes. Fourteen eumenorrheic, healthy and experienced female futsal players were randomly assigned to an intervention group n = 7) or a control group (n = 7). Both groups performed three countermovement jumps before and after the protocol using an inertial system device. The intervention group completed a short-term functional agility and fatigue protocol that simulated the characteristics of futsal, while the control group did not perform any exercise. The results showed a reduction in peak flight time (p = 0.049; d = 0.586), peak concentric work (p = 0.03; d = 1.819) and peak maximum force (p = 0.02; d = 0.782) comparing experimental and control group. No changes in other variables examined were noted between conditions (p > 0.05). These findings indicate that the changes in neuromuscular performance variables, evaluated through a simulated protocol, are established as determinants in the definition of peripheral fatigue in futsal practitioners until 24 h after a demanding intervention.
El objetivo del presente estudio fue evaluar el efecto que tiene el entrenamiento de fuerza basado en la velocidad sobre el rendimiento en jugadores de pelotaris. Los participantes del estudio fueron cinco varones sub 23. Los sujetos realizaron el entrenamiento de fuerza dos veces a la semana durante 8 semanas. Las variables de rendimiento que se evaluaron fueron el salto con contramovimiento (CMJ), sentadilla y press banca a partir de un test de carga-velocidad. El efecto que tuvo el programa de entrenamiento fue calculado en base a la media de los resultados obtenidos en el pre-test y post-test, en base a la prueba t-student, al tamaño del efecto y a la correlación entre las variables analizadas. Como resultado, hubo mejoras significativas tanto en la variable press banca (p=.03; tamaño de efecto (TE=3.03) como en el CMJ (p=.03; TE=1.30) y en la sentadilla (p=.05; TE=1.07). Finalmente, parece ser que el programa de entrenamiento basado en la velocidad de ejecución mejora el rendimiento físico en pelotaris sub23.
The aim of the study was to investigate whether resistance-trained participants can accurately predict changes in barbell velocity, specifically in the deadlift exercise, without feedback from velocity based training (VBT) devices. Seventeen participants (16 male, 1 female; age = 24.7 ± 3.8) were randomized in a counterbalanced, crossover design two experimental sessions that consisted of three sets of Deadlift at 60-and-80% one-repetition maximum (1RM). The number of repetitions were determined by the participants as they were asked to terminate each set when they felt the barbell velocity had reduced by 20%, relative to repetition one. A binomial mixed effects regression model was used to assess the accuracy of participants ability to stop after reaching at least 20% velocity loss. Participants tended to underestimate their proximity to 20% velocity loss and thus had relatively low probability of correctly stopping after reaching this threshold. There was only a 10.49% probability that people could perceive at least 20% velocity loss greater than chance (i.e., 50% probability). Our data, suggests that most participants cannot accurately perceive changes in velocity without exposure to augmented feedback.
This investigation sought to determine the effect of resistance training to failure on functional, structural and neural elbow flexor muscle adaptation. Twenty-eight males completed a 4-week familiarization period and were then counterbalanced on the basis of responsiveness across; non-failure rapid shortening (RS; rapid concentric, 2 s eccentric), non-failure stretch-shortening (SSC; rapid concentric, rapid eccentric), and failure control (C, 2 s concentric, 2 s eccentric), for a 12-week unilateral elbow flexor resistance training regimen, 3 × week using 85% of one repetition maximum (1RM). 1RM, maximal voluntary contraction (MVC), muscle cross-sectional area (CSA), and muscle activation (EMGRMS ) of the agonist, antagonist, and stabilizer muscles were assessed before and after the 12-week training period. The average number of repetitions per set was significantly lower in RS 4.2 [confidence interval (CI): 4.2, 4.3] and SSC 4.2 (CI: 4.2, 4.3) compared with C 6.1 (CI: 5.8, 6.4). A significant increase in 1RM (30.5%), MVC (13.3%), CSA (11.4%), and agonist EMGRMS (22.1%) was observed; however, no between-group differences were detected. In contrast, antagonist EMGRMS increased significantly in SSC (40.5%) and C (23.3%), but decreased in RS (13.5%). Similar adaptations across the three resistance training regimen suggest repetition failure is not critical to elicit significant neural and structural changes to skeletal muscle.
© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
This study aimed to compare the effect on neuromuscular performance of 2 isoinertial resistance training programs that differed only in actual repetition velocity: maximal intended (MaxV) vs. half-maximal (HalfV) concentric velocity. 21 resistance-trained young men were randomly assigned to a MaxV (n=10) or HalfV (n=11) group and trained for 6 weeks using the full squat exercise. A complementary study (n=8) described the acute metabolic and mechanical response to the protocols used. MaxV training resulted in a likely more beneficial effect than HalfV on squat performance: maximum strength (ES: 0.94 vs. 0.54), velocity developed against all (ES: 1.76 vs. 0.88), light (ES: 1.76 vs. 0.75) and heavy (ES: 2.03 vs. 1.64) loads common to pre- and post-tests, and CMJ height (ES: 0.63 vs. 0.15). The effect on 20-m sprint was unclear, however. Both groups attained the greatest improvements in squat performance at their training velocities. Movement velocity seemed to be of greater importance than time under tension for inducing strength adaptations. Slightly higher metabolic stress (blood lactate and ammonia) and CMJ height loss were found for MaxV vs. HalfV, while metabolite levels were low to moderate for both conditions. MaxV may provide a superior stimulus for inducing adaptations directed towards improving athletic performance.
Abstract The purpose of this study was to compare the effect on strength gains of two isoinertial resistance training (RT) programmes that only differed in actual concentric velocity: maximal (MaxV) vs. half-maximal (HalfV) velocity. Twenty participants were assigned to a MaxV (n = 9) or HalfV (n = 11) group and trained 3 times per week during 6 weeks using the bench press (BP). Repetition velocity was controlled using a linear velocity transducer. A complementary study (n = 10) aimed to analyse whether the acute metabolic (blood lactate and ammonia) and mechanical response (velocity loss) was different between the MaxV and HalfV protocols used. Both groups improved strength performance from pre- to post-training, but MaxV resulted in significantly greater gains than HalfV in all variables analysed: one-repetition maximum (1RM) strength (18.2 vs. 9.7%), velocity developed against all (20.8 vs. 10.0%), light (11.5 vs. 4.5%) and heavy (36.2 vs. 17.3%) loads common to pre- and post-tests. Light and heavy loads were identified with those moved faster or slower than 0.80 m·s(-1) (∼60% 1RM in BP). Lactate tended to be significantly higher for MaxV vs. HalfV, with no differences observed for ammonia which was within resting values. Both groups obtained the greatest improvements at the training velocities (≤0.80 m·s(-1)). Movement velocity can be considered a fundamental component of RT intensity, since, for a given %1RM, the velocity at which loads are lifted largely determines the resulting training effect. BP strength gains can be maximised when repetitions are performed at maximal intended velocity.
To propose a manual segmentation method for individual quadriceps femoris (QF) muscles and to test its reliability for muscle volume estimation.
Images were acquired every 5 mm along the thigh using a 3T MRI scanner on 10 young (mean age: 25 years) and 10 older (mean age: 75 years) adults using a three-point 3D Dixon sequence. In each slice, anatomical cross-sectional areas of the individual quadriceps muscles of the dominant leg were outlined by two operators working independently. Differences between operators were assessed by means of Bland-Altman plots and intraclass correlation coefficients (ICC). This study was approved by the local Ethics Committee.
Precise delimitation of individual muscles along the femur often remains challenging, particularly near their insertion areas where some muscles may be partially or totally fused. There was, however, an excellent interoperator segmentation reliability despite a systematic significant difference between operators (ICC > 0.99), mainly due to delineation divergences. Considering all subjects and muscles, differences between operators were all lower than 4.4%.
This work has demonstrated the excellent reliability of manual segmentation to assess cross-sectional areas and therefore the volume of individual QF muscles using MRI. It may serve as a basis for a future segmentation consensus of the QF muscles.J. Magn. Reson. Imaging 2013;. © 2013 Wiley Periodicals, Inc.
This investigation examined the influence of the number of repetitions per set on power output and muscle metabolism during leg press exercise. Six trained men (age 34 ± 6 yr) randomly performed either 5 sets of 10 repetitions (10REP), or 10 sets of 5 repetitions (5REP) of bilateral leg press exercise, with the same initial load and rest intervals between sets. Muscle biopsies (vastus lateralis) were taken before the first set, and after the first and the final sets. Compared with 5REP, 10REP resulted in a markedly greater decrease (P<0.05) of the power output, muscle PCr and ATP content, and markedly higher (P<0.05) levels of muscle lactate and IMP. Significant correlations (P<0.01) were observed between changes in muscle PCr and muscle lactate (R(2) = 0.46), between changes in muscle PCr and IMP (R(2) = 0.44) as well as between changes in power output and changes in muscle ATP (R(2) = 0.59) and lactate (R(2) = 0.64) levels. Reducing the number of repetitions per set by 50% causes a lower disruption to the energy balance in the muscle. The correlations suggest that the changes in PCr and muscle lactate mainly occur simultaneously during exercise, whereas IMP only accumulates when PCr levels are low. The decrease in ATP stores may contribute to fatigue.
Thirty-five healthy men were matched and randomly assigned to one of four training groups that performed high-intensity strength and endurance training (C; n = 9), upper body only high-intensity strength and endurance training (UC; n = 9), high-intensity endurance training (E; n = 8), or high-intensity strength training (ST; n = 9). The C and ST groups significantly increased one-repetition maximum strength for all exercises (P < 0.05). Only the C, UC, and E groups demonstrated significant increases in treadmill maximal oxygen consumption. The ST group showed significant increases in power output. Hormonal responses to treadmill exercise demonstrated a differential response to the different training programs, indicating that the underlying physiological milieu differed with the training program. Significant changes in muscle fiber areas were as follows: types I, IIa, and IIc increased in the ST group; types I and IIc decreased in the E group; type IIa increased in the C group; and there were no changes in the UC group. Significant shifts in percentage from type IIb to type IIa were observed in all training groups, with the greatest shift in the groups in which resistance trained the thigh musculature. This investigation indicates that the combination of strength and endurance training results in an attenuation of the performance improvements and physiological adaptations typical of single-mode training.
To asses if tennis at prepubertal age elicits the hypertrophy of dominant arm muscles.
The volume of the muscles of both arms was determined using magnetic resonance imaging (MRI) in 7 male prepubertal tennis players (TP) and 7 non-active control subjects (CG) (mean age 11.0 ± 0.8 years, Tanner 1-2).
TP had 13% greater total muscle volume in the dominant than in the contralateral arm. The magnitude of inter-arm asymmetry was greater in TP than in CG (13 vs 3%, P<0.001). The dominant arm of TP was 16% greater than the dominant arm of CG (P<0.01), whilst non-dominant arms had similar total muscle volumes in both groups (P = 0.25), after accounting for height as covariate. In TP, dominant deltoid (11%), forearm supinator (55%) and forearm flexors (21%) and extensors (25%) were hypertrophied compared to the contralateral arm (P<0.05). In CG, the dominant supinator muscle was bigger than its contralateral homonimous (63%, P<0.05).
Tennis at prepubertal age is associated with marked hypertrophy of the dominant arm, leading to a marked level of asymmetry (+13%), much greater than observed in non-active controls (+3%). Therefore, tennis particpation at prepubertal age is associated with increased muscle volumes in dominant compared to the non-dominant arm, likely due to selectively hypertrophy of the loaded muscles.
To determine the volume and degree of asymmetry of iliopsoas (IL) and gluteal muscles (GL) in tennis and soccer players.
IL and GL volumes were determined using magnetic resonance imaging (MRI) in male professional tennis (TP) and soccer players (SP), and in non-active control subjects (CG) (n = 8, 15 and 6, respectively).
The dominant and non-dominant IL were hypertrophied in TP (24 and 36%, respectively, P<0.05) and SP (32 and 35%, respectively, P<0.05). In TP the asymmetric hypertrophy of IL (13% greater volume in the non-dominant than in the dominant IL, P<0.01) reversed the side-to-side relationship observed in CG (4% greater volume in the dominant than in the contralateral IL, P<0.01), whilst soccer players had similar volumes in both sides (P = 0.87). The degree of side-to-side asymmetry decreased linearly from the first lumbar disc to the pubic symphysis in TP (r = -0.97, P<0.001), SP (r = -0.85, P<0.01) and CG (r = -0.76, P<0.05). The slope of the relationship was lower in SP due to a greater hypertrophy of the proximal segments of the dominant IL. Soccer and CG had similar GL volumes in both sides (P = 0.11 and P = 0.19, for the dominant and contralateral GL, respectively). GL was asymmetrically hypertrophied in TP. The non-dominant GL volume was 20% greater in TP than in CG (P<0.05), whilst TP and CG had similar dominant GL volumes (P = 0.14).
Tennis elicits an asymmetric hypertrophy of IL and reverses the normal dominant-to-non-dominant balance observed in non-active controls, while soccer is associated to a symmetric hypertrophy of IL. Gluteal muscles are asymmetrically hypertrophied in TP, while SP display a similar size to that observed in controls. It remains to be determined whether the different patterns of IL and GL hypertrophy may influence the risk of injury.
The quest to increase lean body mass is widely pursued by those who lift weights. Research is lacking, however, as to the best approach for maximizing exercise-induced muscle growth. Bodybuilders generally train with moderate loads and fairly short rest intervals that induce high amounts of metabolic stress. Powerlifters, on the other hand, routinely train with high-intensity loads and lengthy rest periods between sets. Although both groups are known to display impressive muscularity, it is not clear which method is superior for hypertrophic gains. It has been shown that many factors mediate the hypertrophic process and that mechanical tension, muscle damage, and metabolic stress all can play a role in exercise-induced muscle growth. Therefore, the purpose of this paper is twofold: (a) to extensively review the literature as to the mechanisms of muscle hypertrophy and their application to exercise training and (b) to draw conclusions from the research as to the optimal protocol for maximizing muscle growth.
The purpose of this study was to examine the efficacy of 8 wk of resistance training to failure versus not to failure training regimens at both moderate and low volumes for increasing upper-body strength and power as well as cardiovascular parameters into a combined resistance and endurance periodized training scheme.
Forty-three trained male rowers were matched and then randomly assigned to four groups that performed the same endurance training but differed on their resistance training regimen: four exercises leading to repetition failure (4RF; n = 14), four exercises not leading to failure (4NRF; n = 15), two exercises not to failure (2NRF; n = 6), and control group (C; n = 8). One-repetition maximum strength and maximal muscle power output during prone bench pull (BP), average power during a 20-min all-out row test (W 20 min), average row power output eliciting a blood lactate concentration of 4 mmol x L(-1) (W 4 mmol x L(-1)), and power output in 10 maximal strokes (W 10 strokes) were assessed before and after 8 wk of periodized training.
4NRF group experienced larger gains in one- repetition maximum strength and muscle power output (4.6% and 6.4%, respectively) in BP compared with both 4RF (2.1% and j1.2%) and 2NRF (0.6% and -0.6%). 4NRF and 2NRF groups experienced larger gains in W 10 strokes (3.6% and 5%) and in W 20 min (7.6% and 9%) compared with those found after 4RF (-0.1% and 4.6%), whereas no significant differences between groups were observed in the magnitude of changes in W 4 mmol x L(-1) (4NRF = 6.2%, 4RF = 5.3%, 2NRF = 6.8%, and C = 4.5%).
An 8-wk linear periodized concurrent strength and endurance training program using a moderate number of repetitions not to failure (4NRF group) provides a favorable environment for achieving greater enhancements in strength, muscle power, and rowing performance when compared with higher training volumes of repetitions to failure in experienced highly trained rowers.
Six women who had participated in a previous 20-wk strength training study for the lower limb detrained for 30-32 wk and subsequently retrained for 6 wk. Seven untrained women also participated in the 6-wk "retraining" phase. In addition, four women from each group volunteered to continue training an additional 7 wk. The initial 20-wk training program caused an increase in maximal dynamic strength, hypertrophy of all three major fiber types, and a decrease in the percentage of type IIb fibers. Detraining had relatively little effect on fiber cross-sectional area but resulted in an increased percentage of type IIb fibers with a concomitant decrease in IIa fibers. Maximal dynamic strength decreased but not to pretraining levels. Retraining for 6 wk resulted in significant increases in the cross-sectional areas of both fast fiber types (IIa and IIab + IIb) compared with detraining values and a decrease in the percentage of type IIb fibers. The 7-wk extension accentuated these trends such that cross-sectional areas continued to increase (nonsignificant) and no IIb fibers could be found. Similar results were found for the nonpreviously trained women. These data suggest that rapid muscular adaptations occur as a result of strength training in previously trained as well as non-previously trained women. Some adaptations (fiber area and maximal dynamic strength) may be retained for long periods during detraining and may contribute to a rapid return to "competitive" form.
The role of intramuscular metabolite changes in the adaptations following isometric strength training was examined by comparing the effect of short, intermittent contractions (IC) and longer, continuous (CC) contractions. In a parallel study, the changes in phosphate metabolites and pH were examined during the two protocols using whole-body nuclear magnetic resonance spectroscopy (NMRS). Seven subjects trained three time per week for 14 weeks. The right leg was trained using four sets of ten contractions, each lasting 3 s with a 2-s rest period between each contraction and 2 min between each set. The left leg was trained using four 30-s contractions with a 1-min rest period between each. Both protocols involved isometric contractions at 70% of a maximum voluntary isometric contraction (MVC). The MVC, length:tension and force:velocity relationships and cross-sectional area (CSA) of each leg were measured before and after training. The increase in isometric strength was significantly greater (P = 0.041) for the CC leg (median 54.7%; P = 0.022) than for IC (31.5%; P = 0.022). There were no significant differences between the two protocols for changes in the length:tension or force:velocity relationships. There were significant increases in muscle CSA for the CC leg only. NMRS demonstrated that the changes in phosphate metabolites and pH were greater for the CC protocol. These findings suggest that factors related to the greater metabolite changes during CC training results in greater increases in isometric strength and muscle CSA.
Skeletal muscle (SM) is a large body compartment of biological importance, but it remains difficult to quantify SM with affordable and practical methods that can be applied in clinical and field settings.
The objective of this study was to develop and cross-validate anthropometric SM mass prediction models in healthy adults.
SM mass, measured by using whole-body multislice magnetic resonance imaging, was set as the dependent variable in prediction models. Independent variables were organized into 2 separate formulas. One formula included mainly limb circumferences and skinfold thicknesses [model 1: height (in m) and skinfold-corrected upperarm, thigh, and calf girths (CAG, CTG, and CCG, respectively; in cm)]. The other formula included mainly body weight (in kg) and height (model 2). The models were developed and cross-validated in nonobese adults [body mass index (in kg/m(2)) < 30].
Two SM (in kg) models for nonobese subjects (n = 244) were developed as follows: SM = Ht x (0.00744 x CAG(2) + 0.00088 x CTG(2) + 0.00441 x CCG(2)) + 2.4 x sex - 0.048 x age + race + 7.8, where R:(2) = 0.91, P: < 0.0001, and SEE = 2.2 kg; sex = 0 for female and 1 for male, race = -2.0 for Asian, 1.1 for African American, and 0 for white and Hispanic, and SM = 0.244 x BW + 7.80 x Ht + 6.6 x sex - 0.098 x age + race - 3.3, where R:(2) = 0.86, P: < 0.0001, and SEE = 2.8 kg; sex = 0 for female and 1 for male, race = -1.2 for Asian, 1.4 for African American, and 0 for white and Hispanic.
These 2 anthropometric prediction models, the first developed in vivo by using state-of-the-art body-composition methods, are likely to prove useful in clinical evaluations and field studies of SM mass in nonobese adults.
High resistance training enhances muscular strength, and recent work has suggested an important role for metabolite accumulation in this process.
To investigate the role of fatigue and metabolite accumulation in strength gains by comparing highly fatiguing and non-fatiguing isotonic training protocols.
Twenty three healthy adults (18-29 years of age; eight women) were assigned to either a high fatigue protocol (HF: four sets of 10 repetitions with 30 seconds rest between sets) to maximise metabolic stress or a low fatigue protocol (LF: 40 repetitions with 30 seconds between each repetition) to minimise changes. Subjects lifted on average 73% of their 1 repetition maximum through the full range of knee extension with both legs, three times a week. Quadriceps isometric strength of each leg was measured at a knee joint angle of 1.57 rad (90 degrees ), and a Cybex 340 isokinetic dynamometer was used to measure the angle-torque and torque-velocity relations of the non-dominant leg.
At the mid-point of the training, the HF group had 50% greater gains in isometric strength, although this was not significant (4.5 weeks: HF, 13.3 (4.4)%; LF, 8.9 (3.6)%). This rate of increase was not sustained by the HF group, and after nine weeks of training all the strength measurements showed similar improvements for both groups (isometric strength: HF, 18.2 (3.9)%; LF, 14.5 (4.0)%). The strength gains were limited to the longer muscle lengths despite training over the full range of movement.
Fatigue and metabolite accumulation do not appear to be critical stimuli for strength gain, and resistance training can be effective without the severe discomfort and acute physical effort associated with fatiguing contractions.
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.
Thirty-two untrained men [mean (SD) age 22.5 (5.8) years, height 178.3 (7.2) cm, body mass 77.8 (11.9) kg] participated in an 8-week progressive resistance-training program to investigate the "strength-endurance continuum". Subjects were divided into four groups: a low repetition group (Low Rep, n = 9) performing 3-5 repetitions maximum (RM) for four sets of each exercise with 3 min rest between sets and exercises, an intermediate repetition group (Int Rep, n = 11) performing 9-11 RM for three sets with 2 min rest, a high repetition group (High Rep, n = 7) performing 20-28 RM for two sets with 1 min rest, and a non-exercising control group (Con, n = 5). Three exercises (leg press, squat, and knee extension) were performed 2 days/week for the first 4 weeks and 3 days/week for the final 4 weeks. Maximal strength [one repetition maximum, 1RM), local muscular endurance (maximal number of repetitions performed with 60% of 1RM), and various cardiorespiratory parameters (e.g., maximum oxygen consumption, pulmonary ventilation, maximal aerobic power, time to exhaustion) were assessed at the beginning and end of the study. In addition, pre- and post-training muscle biopsy samples were analyzed for fiber-type composition, cross-sectional area, myosin heavy chain (MHC) content, and capillarization. Maximal strength improved significantly more for the Low Rep group compared to the other training groups, and the maximal number of repetitions at 60% 1RM improved the most for the High Rep group. In addition, maximal aerobic power and time to exhaustion significantly increased at the end of the study for only the High Rep group. All three major fiber types (types I, IIA, and IIB) hypertrophied for the Low Rep and Int Rep groups, whereas no significant increases were demonstrated for either the High Rep or Con groups. However, the percentage of type IIB fibers decreased, with a concomitant increase in IIAB fibers for all three resistance-trained groups. These fiber-type conversions were supported by a significant decrease in MHCIIb accompanied by a significant increase in MHCIIa. No significant changes in fiber-type composition were found in the control samples. Although all three training regimens resulted in similar fiber-type transformations (IIB to IIA), the low to intermediate repetition resistance-training programs induced a greater hypertrophic effect compared to the high repetition regimen. The High Rep group, however, appeared better adapted for submaximal, prolonged contractions, with significant increases after training in aerobic power and time to exhaustion. Thus, low and intermediate RM training appears to induce similar muscular adaptations, at least after short-term training in previously untrained subjects. Overall, however, these data demonstrate that both physical performance and the associated physiological adaptations are linked to the intensity and number of repetitions performed, and thus lend support to the "strength-endurance continuum".
High-resistance strength training (HRST) is one of the most widely practiced forms of physical activity, which is used to enhance athletic performance, augment musculo-skeletal health and alter body aesthetics. Chronic exposure to this type of activity produces marked increases in muscular strength, which are attributed to a range of neurological and morphological adaptations. This review assesses the evidence for these adaptations, their interplay and contribution to enhanced strength and the methodologies employed. The primary morphological adaptations involve an increase in the cross-sectional area of the whole muscle and individual muscle fibres, which is due to an increase in myofibrillar size and number. Satellite cells are activated in the very early stages of training; their proliferation and later fusion with existing fibres appears to be intimately involved in the hypertrophy response. Other possible morphological adaptations include hyperplasia, changes in fibre type, muscle architecture, myofilament density and the structure of connective tissue and tendons. Indirect evidence for neurological adaptations, which encompasses learning and coordination, comes from the specificity of the training adaptation, transfer of unilateral training to the contralateral limb and imagined contractions. The apparent rise in whole-muscle specific tension has been primarily used as evidence for neurological adaptations; however, morphological factors (e.g. preferential hypertrophy of type 2 fibres, increased angle of fibre pennation, increase in radiological density) are also likely to contribute to this phenomenon. Changes in inter-muscular coordination appear critical. Adaptations in agonist muscle activation, as assessed by electromyography, tetanic stimulation and the twitch interpolation technique, suggest small, but significant increases. Enhanced firing frequency and spinal reflexes most likely explain this improvement, although there is contrary evidence suggesting no change in cortical or corticospinal excitability. The gains in strength with HRST are undoubtedly due to a wide combination of neurological and morphological factors. Whilst the neurological factors may make their greatest contribution during the early stages of a training programme, hypertrophic processes also commence at the onset of training.
Acute hormonal and neuromuscular responses and recovery three days after the exercises were examined during the maximum repetitions (MR) and forced repetitions (FR) resistance exercise protocols in 16 male athletes. MR included 4 sets of leg presses, 2 sets of squats and 2 sets of knee extensions (with 12 RM) with a 2-min recovery between the sets and 4 min between the exercises. In FR the initial load was chosen to be higher than in MR so that the subject could not lift 12 repetitions per set by himself. After each set to failure the subject was assisted to perform the remaining repetitions to complete the 12 repetitions per set. Thus the exercise intensity was greater in FR than in MR. Both loading protocols led to the great acute increases (p < 0.05 - 0.001) in serum testosterone, free testosterone, cortisol and GH concentrations. However, the responses in cortisol (p < 0.05) and GH (p < 0.01) were larger in FR than in MR. The decrease of 56.5 % (p < 0.001) in maximal isometric force in FR was greater (p < 0.001) than that of 38.3 % in MR (p < 0.001) and force remained lower (p < 0.01) during the recovery in FR compared to MR. The larger decrease in isometric strength in FR than in MR was also associated with the decreased maximal voluntary EMG of the loaded muscles. The data indicate that the forced repetition exercise system induced greater acute hormonal and neuromuscular responses than a traditional maximum repetition exercise system and therefore it may be used to manipulate acute resistance exercise variables in athletes.
The effects of a training program consisting of weight lifting combined with plyometric exercises on kicking performance, myosin heavy-chain composition (vastus lateralis), physical fitness, and body composition (using dual-energy X-ray absorptiometry (DXA)) was examined in 37 male physical education students divided randomly into a training group (TG: 16 subjects) and a control group (CG: 21 subjects). The TG followed 6 weeks of combined weight lifting and plyometric exercises. In all subjects, tests were performed to measure their maximal angular speed of the knee during in-step kicks on a stationary ball. Additional tests for muscle power (vertical jump), running speed (30 m running test), anaerobic capacity (Wingate and 300 m running tests), and aerobic power (20 m shuttle run tests) were also performed. Training resulted in muscle hypertrophy (+4.3%), increased peak angular velocity of the knee during kicking (+13.6%), increased percentage of myosin heavy-chain (MHC) type IIa (+8.4%), increased 1 repetition maximum (1 RM) of inclined leg press (ILP) (+61.4%), leg extension (LE) (+20.2%), leg curl (+15.9%), and half squat (HQ) (+45.1%), and enhanced performance in vertical jump (all p < or = 0.05). In contrast, MHC type I was reduced (-5.2%, p < or = 0.05) after training. In the control group, these variables remained unchanged. In conclusion, 6 weeks of strength training combining weight lifting and plyometric exercises results in significant improvement of kicking performance, as well as other physical capacities related to success in football (soccer).
Drinkwater, E.J., T.W. Lawton, R.P. Lindsell, D.B. Pyne, P.H. Hunt, and M.J. McKenna. Training leading to repetition failure contributes to bench press strength gains in elite junior athletes. J. Strength Cond. Res. 19(2):382-388. 2005. The purpose of this study was to investigate the importance of training leading to repetition failure in the performance of 2 different tests: 6 repetition maximum (6RM) bench press strength and 40-kg bench throw power in elite junior athletes. Subjects were 26 elite junior male basketball players (n 12; age = 18.6 +/- 0.3 years; height = 202.0 +/- 11.6 cm; mass = 97.0 +/- 12.9 kg; mean SD) and soccer players (n = 14; age = 17.4 +/- 0.5 years; height = 179.0 +/- 7.0 cm; mass = 75.0 +/- 7.1 kg) with a history of greater than 6 months' strength training. Subjects were initially tested twice for 6RM bench press mass and 40-kg Smith machine bench throw power output (in watts) to establish retest reliability. Subjects then undertook bench press training with 3 sessions per week for 6 weeks, using equal volume programs (24 repetitions X 80-105% 6RM in 13 minutes 20 seconds). Subjects were assigned to one of two experimental groups designed either to elicit repetition failure with 4 sets of 6 repetitions every 260 seconds (RF4x6) or allow all repetitions to be completed with 8 sets of 3 repetitions every 113 seconds (NF8x3). The RF4X6 treatment elicited substantial increases in strength (7.3 +/- 2.4 kg, + 9.5%, p < 0.001) and power (40.8 +/- 24.1 W, + 10.6%, p < 0.001), while the NF8X3 group elicited 3.6 +/- 3.0 kg (+ 5.0%, p < 0.005) and 25 +/- 19.0 W increases (+ 6.8%, p < 0.001). The improvements in the RF4x6 group were greater than those in the repetition rest group for both strength (p < 0.005) and power (p < 0.05). Bench press training that leads to repetition failure induces greater strength gains than nonfailure training in the bench press exercise for elite junior team sport athletes.