Effectiveness of Accentuated Eccentric Loading: Contingent on Concentric Load

2021 ◽  
Vol 16 (1) ◽  
pp. 66-72
Author(s):  
Justin J. Merrigan ◽  
James J. Tufano ◽  
Michael Falzone ◽  
Margaret T. Jones
Keyword(s):  
Peak Power ◽  
Performance Enhancement ◽  
Force Plate ◽  
Relative Difference ◽  
Peak Force ◽  
Acute Effects ◽  
Mean Power ◽  
Mean Velocity ◽  
Eccentric Load ◽  
Back Squat

Purpose: To identify acute effects of a single accentuated eccentric loading (AEL) repetition on subsequent back-squat kinetics and kinematics with different concentric loads. Methods: Resistance-trained men (N = 21) participated in a counterbalanced crossover design and completed 4 protocols (sets × repetitions at eccentric/concentric) as follows: AEL65, 3 × 5 at 120%/65% 1-repetition maximum (1-RM); AEL80, 3 × 3 at 120%/80% 1-RM; TRA65, 3 × 5 at 65%/65% 1-RM; and TRA80, 3 × 3 at 80%/80% 1-RM. During AEL, weight releasers disengaged from the barbell after the eccentric phase of the first repetition and remained off for the remaining repetitions. All repetitions were performed on a force plate with linear position transducers attached to the barbell, from which eccentric and concentric peak and mean velocity, force, and power were derived. Results: Eccentric peak velocity (−0.076 [0.124] m·s−1; P = .01), concentric peak force (187.8 [284.4] N; P = .01), eccentric mean power (−145.2 [62.0] W; P = .03), and eccentric peak power (−328.6 [93.7] W; P < .01) during AEL65 were significantly greater than TRA65. When collapsed across repetitions, AEL65 resulted in slower eccentric velocity and power during repetition 1 but faster eccentric and concentric velocity and power in subsequent repetitions (P ≤ .04). When comparing AEL80 with TRA80, concentric peak force (133.8 [56.9] N; P = .03), eccentric mean power (−83.57 [38.0] W; P = .04), and eccentric peak power (−242.84 [67.3] W; P < .01) were enhanced. Conclusions: Including a single supramaximal eccentric phase of 120% 1-RM increased subsequent velocity and power with concentric loads of 65% 1-RM, but not 80% 1-RM. Therefore, AEL is sensitive to the magnitude of concentric loads, which requires a large relative difference to the eccentric load, and weight releasers may not need to be reloaded to induce performance enhancement.

Reducing the Loss of Velocity and Power in Women Athletes via Rest Redistribution

2020 ◽  
Vol 15 (2) ◽  
pp. 255-261 ◽  
Author(s):  
Justin J. Merrigan ◽  
James J. Tufano ◽  
Jonathan M. Oliver ◽  
Jason B. White ◽  
Jennifer B. Fields ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Repeated Measures ◽  
Peak Power ◽  
Force Plate ◽  
Mean Power ◽  
Mean Velocity ◽  
Back Squat ◽  
Percentage Loss ◽  
Repeated Measures Analysis ◽  
Training History

Purpose: To examine rest redistribution (RR) effects on back squat kinetics and kinematics in resistance-trained women. Methods: Twelve women from strength and college sports (5.0 [2.2] y training history) participated in the randomized crossover design study with 72 hours between sessions (3 total). Participants completed 4 sets of 10 repetitions using traditional sets (120-s interset rest) and RR (30-s intraset rest in the middle of each set; 90-s interset rest) with 70% of their 1-repetition maximum. Kinetics and kinematics were sampled via force plate and 4 linear position transducers. The greatest value of repetitions 1 to 3 (peak repetition) was used to calculate percentage loss, [(repetition 10–peak repetition)/(peak repetition) × 100], and maintenance, {100–[(set mean–peak repetition)/(peak repetition)] × 100}, of velocity and power for each set. Repeated-measures analysis of variance was used for analyses (P < .05). Results: Mean and peak force did not differ between conditions. A condition × repetition interaction existed for peak power (P = .049) but not for peak velocity (P = .110). Peak power was greater in repetitions 7 to 9 (P < .05; d = 1.12–1.27) during RR. The percentage loss of velocity (95% confidence interval, –0.22% to –7.22%; P = .039) and power (95% confidence interval, –1.53% to –7.87%; P = .008) were reduced in RR. Mean velocity maintenance of sets 3 (P = .036; d = 1.90) and 4 (P = .015; d = 2.30) and mean power maintenance of set 4 (P = .006; d = 2.65) were greater in RR. Conclusion: By redistributing a portion of long interset rest into the middle of a set, velocity and power were better maintained. Therefore, redistributing rest may be beneficial for reducing fatigue in resistance-trained women.

Validity of Various Methods for Determining Velocity, Force, and Power in the Back Squat

2017 ◽  
Vol 12 (9) ◽  
pp. 1170-1176 ◽  
Author(s):  
Harry G. Banyard ◽  
Ken Nosaka ◽  
Kimitake Sato ◽  
G. Gregory Haff
Keyword(s):  
Peak Power ◽  
Peak Velocity ◽  
Force Plate ◽  
Testing Device ◽  
Mean Power ◽  
Mean Velocity ◽  
Repetition Maximum ◽  
Back Squat ◽  
Free Weight ◽  
Criterion Variables

Purpose:To examine the validity of 2 kinematic systems for assessing mean velocity (MV), peak velocity (PV), mean force (MF), peak force (PF), mean power (MP), and peak power (PP) during the full-depth free-weight back squat performed with maximal concentric effort. Methods:Ten strength-trained men (26.1 ± 3.0 y, 1.81 ± 0.07 m, 82.0 ± 10.6 kg) performed three 1-repetition-maximum (1RM) trials on 3 separate days, encompassing lifts performed at 6 relative intensities including 20%, 40%, 60%, 80%, 90%, and 100% of 1RM. Each repetition was simultaneously recorded by a PUSH band and commercial linear position transducer (LPT) (GymAware [GYM]) and compared with measurements collected by a laboratory-based testing device consisting of 4 LPTs and a force plate. Results:Trials 2 and 3 were used for validity analyses. Combining all 120 repetitions indicated that the GYM was highly valid for assessing all criterion variables while the PUSH was only highly valid for estimations of PF (r = .94, CV = 5.4%, ES = 0.28, SEE = 135.5 N). At each relative intensity, the GYM was highly valid for assessing all criterion variables except for PP at 20% (ES = 0.81) and 40% (ES = 0.67) of 1RM. Moreover, the PUSH was only able to accurately estimate PF across all relative intensities (r = .92–.98, CV = 4.0–8.3%, ES = 0.04–0.26, SEE = 79.8–213.1 N). Conclusions:PUSH accuracy for determining MV, PV, MF, MP, and PP across all 6 relative intensities was questionable for the back squat, yet the GYM was highly valid at assessing all criterion variables, with some caution given to estimations of MP and PP performed at lighter loads.

scholarly journals Assessment of Back-Squat Performance at Submaximal Loads: Is the Reliability Affected by the Variable, Exercise Technique, or Repetition Criterion?

2021 ◽  
Vol 18 (9) ◽  
pp. 4626
Author(s):  
Alejandro Pérez-Castilla ◽  
Danica Janicijevic ◽  
Zeki Akyildiz ◽  
Deniz Senturk ◽  
Amador García-Ramos
Keyword(s):  
Peak Power ◽  
Peak Velocity ◽  
Average Score ◽  
Experimental Session ◽  
Mean Power ◽  
Mean Velocity ◽  
Repetition Maximum ◽  
Performance Variables ◽  
Back Squat ◽  
Squat Exercise

This study aimed to compare the between-session reliability of different performance variables during 2 variants of the Smith machine back-squat exercise. Twenty-six male wrestlers performed 5 testing sessions (a 1-repetition maximum [1RM] session, and 4 experimental sessions [2 with the pause and 2 with the rebound technique]). Each experimental session consisted of performing 3 repetitions against 5 loads (45–55–65–75–85% of the 1RM). Mean velocity (MV), mean power (MP), peak velocity (PV), and peak power (PP) variables were recorded by a linear position transducer (GymAware PowerTool). The best and average scores of the 3 repetitions were considered for statistical analyses. The coefficient of variation (CV) ranged from 3.89% (best PV score at 55% 1 RM using the pause technique) to 10.29% (average PP score at 85% 1 RM using the rebound technique). PP showed a lower reliability than MV, MP, and PV (CVratio ≥ 1.26). The reliability was comparable between the exercise techniques (CVratio = 1.08) and between the best and average scores (CVratio = 1.04). These results discourage the use of PP to assess back-squat performance at submaximal loads. The remaining variables (MV, MP, or PV), exercise techniques (pause or rebound), and repetition criteria (best score or average score) can be indistinctly used due to their acceptable and comparable reliability.

scholarly journals Enhancement of Countermovement Jump Performance Using a Heavy Load with Velocity-Loss Repetition Control in Female Volleyball Players

2021 ◽  
Vol 18 (21) ◽  
pp. 11530
Author(s):  
Michal Krzysztofik ◽  
Rafal Kalinowski ◽  
Robert Trybulski ◽  
Aleksandra Filip-Stachnik ◽  
Petr Stastny
Keyword(s):  
Body Mass ◽  
Repeated Measures ◽  
Performance Enhancement ◽  
Countermovement Jump ◽  
Mean Power ◽  
Mean Velocity ◽  
Heavy Load ◽  
Jump Performance ◽  
Volleyball Players ◽  
Post Hoc

Although velocity control in resistance training is widely studied, its utilization in eliciting post-activation performance enhancement (PAPE) responses receives little attention. Therefore, this study aimed to evaluate the effectiveness of heavy-loaded barbell squats (BS) with velocity loss control conditioning activity (CA) on PAPE in subsequent countermovement jump (CMJ) performance. Sixteen resistance-trained female volleyball players participated in this study (age: 24 ± 5 yrs.; body mass: 63.5 ± 5.2 kg; height: 170 ± 6 cm; relative BS one-repetition maximum (1RM): 1.45 ± 0.19 kg/body mass). Each participant performed two different conditions: a set of the BS at 80% 1 RM with repetitions performed until a mean velocity loss of 10% as the CA or a control condition without CA (CNTRL). To assess changes in jump height (JH) and relative mean power output (MP), the CMJ was performed 5 min before and throughout the 10 min after the CA. The two-way analysis of variance with repeated measures showed a significant main effect of condition (p = 0.008; η2 = 0.387) and time (p < 0.0001; η2 = 0.257) for JH. The post hoc test showed a significant decrease in the 10th min in comparison to the value from baseline (p < 0.006) for the CNTRL condition. For the MP, a significant interaction (p = 0.045; η2 = 0.138) was found. The post hoc test showed a significant decrease in the 10th min in comparison to the values from baseline (p < 0.006) for the CNTRL condition. No significant differences were found between all of the time points and the baseline value for the CA condition. The CA used in the current study fails to enhance subsequent countermovement jump performance in female volleyball players. However, the individual analysis showed that 9 out of the 16 participants (56%) responded positively to the applied CA, suggesting that the PAPE effect may be individually dependent and should be carefully verified before implementation in a training program.

scholarly journals Does Post-Activation Potentiation Protocols affect Anaerobic Performance in women Taolu Wushu Athletes?

2021 ◽  
Author(s):  
José Afonso ◽  
Hengameh Moradian ◽  
Rasoul Eslami ◽  
Alexandre Martins ◽  
Abdolhossein Parnow
Keyword(s):  
Peak Power ◽  
Performance Enhancement ◽  
Anaerobic Performance ◽  
Fatigue Index ◽  
Short Term ◽  
Mean Power ◽  
Significant Difference ◽  
Strength Based ◽  
Rest Time ◽  
Lactate Levels

Abstract Introduction: Post-activation potentiation has an influence on short duration and high intensity function. This study aimed to answer this question whether post-activation potentiation protocol in different models has effect on anaerobic performance in women Wushu athletes. Methods: Women elite Taolu Wushu athletes participated in current crossover design study. (i) specific Wushu WU (Wushu WU); (ii) Strength-based WU (StreWU); and (iii) Speed-based WU (SpeWU) were performed by Wushu athletes in three inconsecutive days separated by 48 h. Five minutes after each WU protocols, Running-Based Anaerobic Sprint Test (RAST) was performed. Heart rate, immediately, and blood lactate were measured for 4 times: before WU protocols, immediately after WU protocols, before RAST, immediately after RAST.Results: Data analysis revealed significant differences in 4 time points of lactate levels (p=0.001; d=1.71), although no significant difference among protocols was observed. Values of variables obtained from RAST showed that StreWU had a significant impact on minimum power (p<0.05; d=-0.795) comparing to WushuWU and on fatigue index comparing to SpeWU (p<0.05; d=-0.799). No significant differences were found among the WU protocols for peak power and mean power.Conclusion: All WU protocols had mostly the same effect, and PAP was not very effective. Possibly, the WU protocols generated too much fatigue, due to the short-term rest time. However, longer intervals would likely enter the realm of post-activation performance enhancement, which is distinct from PAP.

Cluster Sets: Permitting Greater Mechanical Stress Without Decreasing Relative Velocity

2017 ◽  
Vol 12 (4) ◽  
pp. 463-469 ◽  
Author(s):  
James J. Tufano ◽  
Jenny A. Conlon ◽  
Sophia Nimphius ◽  
Lee E. Brown ◽  
Harry G. Banyard ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Peak Velocity ◽  
Training Load ◽  
Mean Power ◽  
Mean Velocity ◽  
External Work ◽  
Back Squat ◽  
Mechanical Power Output ◽  
Cluster Sets ◽  
External Loads

Purpose:To determine the effects of intraset rest frequency and training load on muscle time under tension, external work, and external mechanical power output during back-squat protocols with similar changes in velocity.Methods:Twelve strength-trained men (26.0 ± 4.2 y, 83.1 ± 8.8 kg, 1.75 ± 0.06 m, 1.88:0.19 one-repetition-maximum [1RM] body mass) performed 3 sets of 12 back squats using 3 different set structures: traditional sets with 60% 1RM (TS), cluster sets of 4 with 75% 1RM (CS4), and cluster sets of 2 with 80% 1RM (CS2). Repeated-measures ANOVAs were used to determine differences in peak force (PF), mean force (MF), peak velocity (PV), mean velocity (MV), peak power (PP), mean power (MP), total work (TW), total time under tension (TUT), percentage mean velocity loss (%MVL), and percentage peak velocity loss (%PVL) between protocols.Results:Compared with TS and CS4, CS2 resulted in greater MF, TW, and TUT in addition to less MV, PV, and MP. Similarly, CS4 resulted in greater MF, TW, and TUT in addition to less MV, PV, and MP than TS did. There were no differences between protocols for %MVL, %PVL, PF, or PP.Conclusions:These data show that the intraset rest provided in CS4 and CS2 allowed for greater external loads than with TS, increasing TW and TUT while resulting in similar PP and %VL. Therefore, cluster-set structures may function as an alternative method to traditional strength- or hypertrophy-oriented training by increasing training load without increasing %VL or decreasing PP.

scholarly journals Biomechanical Analysis of the Jump Shot in Basketball

2014 ◽  
Vol 42 (1) ◽  
pp. 73-79 ◽  
Author(s):  
Artur Struzik ◽  
Bogdan Pietraszewski ◽  
Jerzy Zawadzki
Keyword(s):  
Peak Power ◽  
High Performance ◽  
Force Plate ◽  
Lower Limbs ◽  
Biomechanical Analysis ◽  
Countermovement Jump ◽  
Mean Power ◽  
Basketball Players ◽  
Arm Swing ◽  
High Level

Abstract Basketball players usually score points during the game using the jump shot. For this reason, the jump shot is considered to be the most important element of technique in basketball and requires a high level of performance. The aim of this study was to compare the biomechanical characteristics of the lower limbs during a jump shot without the ball and a countermovement jump without an arm swing. The differences between variables provide information about the potential that an athlete can utilise during a game when performing a jump shot. The study was conducted among 20 second-league basketball players by means of a Kistler force plate and the BTS SMART system for motion analysis. The variables measured included the take-off time, mean power, peak power, relative mean power, jump height, maximum landing force and calculated impact ratio. Surprisingly, more advantageous variables were found for the jump shot. This finding suggests a very high performance level in the jump shot in the studied group and a maximum utilisation of their motor abilities. Both types of jumps were characterised by high mean and peak power values and average heights. The high forces at landing, which result in considerable impact ratios, may have prompted the studied group to land softly. Use of the countermovement jump without an arm swing is recommended to assess and predict the progression of player’s jumping ability

Power– and velocity–load relationships to improve resistance exercise performance

2018 ◽  
Vol 232 (4) ◽  
pp. 349-359 ◽  
Author(s):  
Manuel V Garnacho-Castaño ◽  
Arturo Muñoz-González ◽  
María A Garnacho-Castaño ◽  
José L Maté-Muñoz
Keyword(s):  
Power Output ◽  
Peak Power ◽  
Bench Press ◽  
Peak Velocity ◽  
Peak Power Output ◽  
Mean Power ◽  
Mean Velocity ◽  
Maximal Power Output ◽  
Power Load ◽  
The Military

Knowledge of the power– and velocity–load relationships is a key factor to guide loads during resistance training and optimize sports performance. This study compares mean velocity–, peak velocity– and power–load relationships, and determines the load which elicits maximal power output in the military press and bench press. Fifty-seven healthy, active men were randomly assigned to a bench press (n = 28) or military press (n = 29) group. In separate test sessions, concentric-only or eccentric-concentric sequences of each exercise were performed in random order as incremental isoinertial load tests. Both mean velocity and peak velocity were highly related with the load lifted (% 1RM) in both bench press and military press (mean velocity: R2 = 0.94 and 0.95; peak velocity: R2 = 0.93 and 0.93, respectively). The loads maximizing mean power and peak power output were similar for the eccentric-concentric versus concentric sequences in bench press and military press. The loads maximizing mean power and peak power were between 54% and 57.5% 1RM for the bench press and 59.8%–63.1% 1RM for the military press. For the bench press, no significant differences were observed in mean power from 30% to 80% 1RM and peak power from 30% to 95% 1RM. For the military press, no significant differences were observed in mean power from 40% to 80% 1RM and peak power from 30% to 90%/95% 1RM. The close relationship detected between mean velocity or peak velocity and load means that the % 1RM can be estimated according to mean velocity and peak velocity. In both exercises, a broad range of relative intensities could be used at which power output is not significantly different than that at maximized power output (mean = 30%/40%–80% 1RM; peak = 30%–90%/95%). Mean velocity lower than approximately 0.33 m s−1 for bench press and 0.4 m s−1 for military press, as well as peak velocity lower than approximately 0.4 m s−1 for bench press and 0.5 m s−1 for military press do not optimize power output responses. The eccentric action was a determining factor for increasing power output only in bench press.

scholarly journals The Effects of Plyometric Conditioning Exercises on Volleyball Performance with Self-Selected Rest Intervals

2021 ◽  
Vol 11 (18) ◽  
pp. 8329
Author(s):  
Michal Krzysztofik ◽  
Rafal Kalinowski ◽  
Aleksandra Filip-Stachnik ◽  
Michal Wilk ◽  
Adam Zajac
Keyword(s):  
Performance Enhancement ◽  
Lower Body ◽  
Mean Power ◽  
Back Squat ◽  
Specific Performance ◽  
Volleyball Players ◽  
Before And After ◽  
Ball Velocity ◽  
Mean Power Output ◽  
Rest Intervals

Post-activation performance enhancement remains a topic of debate in sport science. The purpose of this study was to examine the effects of lower-body plyometric conditioning activity (CA) with a self-selected intra-complex rest interval on upper and lower-body volleyball specific performance. Eleven resistance-trained female volleyball players participated in the study (age: 20 ± 2 years; body mass: 67.8 ± 4.4 kg; height: 178 ± 6 cm; half back squat one-repetition maximum: 78.6 ± 10.2 kg; experience in resistance training: 5.5 ± 2.1 years and in volleyball training: 10 ± 2.3 years). Each participant performed a plyometric CA followed by two different sport-specific tests: an attack jump and a standing spike attack. The changes in jump height (JH), relative mean power output (MP) and ball velocity (BV) were analyzed before and after the CA with self-selected rest intervals. The applied plyometric CA with self-selected intra-complex rest intervals led to an insignificant decline in JH (p = 0.594; effect size [ES]: −0.27) and MP (p = 0.328; ES: −0.46) obtained during the attack jump as well as a significant decline in BV (p = 0.029; ES: −0.72) during the standing spike attack. This study showed that a plyometric CA with self-selected intra-complex rest intervals failed to elicit localized and non-localized PAPE effect in a group of sub-elite volleyball players.

scholarly journals Comparison of the Velocity and Power Parameters During Loaded-Squat Jump Exercise of National Athletes in Different Branches

2018 ◽  
Vol 6 (5) ◽  
pp. 16 ◽  
Author(s):  
Ibrahim Can ◽  
Hamit Cihan ◽  
Erdal Ari ◽  
Serdar Bayrakdaroglu
Keyword(s):  
Peak Power ◽  
Mean Power ◽  
Mean Velocity ◽  
Squat Jump ◽  
Jump Exercise ◽  
Significant Difference ◽  
Body Weights ◽  
Statistical Program ◽  
One Way Anova ◽  
Analyze Data

The aim of this investigation is to compare velocity and power variables during loaded-squat jump (SJLoaded) exercise of national athletes dealing with different sports branches and to identify whether velocity and power parameters become different or not according to branches. In accordance with this purpose, a total of 36 national athletes (age: 20.3±1.68 years; height: 173.5±6.46 cm; weight: 72.3±10.29 kg) composed of 12 wrestlers (age: 19.5±.90 years; height: 172.3±6.19 cm; weight: 75.5±13.9 kg), 12 arm wrestlers (age: 20.5±2.02 years; height: 174.7±4.76 cm; weight: 72.6±8.31 kg) and 12 kickboxers (age: 20.7±1.81 years; height: 173.5±8.29 cm; weight: 68.9±6.94 kg) dealing with different sports branches have voluntarily participated in this study. For identifying velocity and power parameters, SJLoaded exercise was executed with an external load that corresponds to 40% of body weights of the athletes by utilizing an isoinertial velocity transducer (T-Force dynamic measurement system) and values of mean velocity (MV), mean propulsive velocity (MPV), peak velocity (PV), mean power (MP), mean propulsive power (MPP) and peak power (PP) were determined. All data analyzes were performed in the SPSS 16.0 statistical program. Firstly, in order to analyze data, it was determined that the data indicated normal distribution by looking at the Shapiro-Wilk coefficient regarding the normality of the distribution of the data. Therefore one-way analysis of variance (One-way ANOVA) was utilized to identify statistical significant differences among athletes competing in different branches with regard to the velocity and power variables during the SJLoaded exercise. According to analyze results, no statistical significant difference wasn’t seen among branches with regard to MV [f (2.33) = 1.306], MPV [f (2. 33)=2.195], PV [f (2. 33)=2.242], MP [f (2. 33)=1.225], MPP [f (2. 33)=2.787] and PP [f (2. 33)= 2.607] parameters during SJLoaded exercise (p>0.05). The velocity and power parameters obtained in the SJLoaded exercise don’t differ according to the branches.

Sign in / Sign up

Export Citation Format

Share Document