scholarly journals The influence of the ACTN3 R577X polymorphism in the responsiveness to post-activation jump performance enhancement in untrained young men

2021 ◽  
Vol 23 ◽  
Author(s):  
Guilherme Beneduzzi Mantovani ◽  
Renan Vieira Barreto ◽  
Victor Alvino de Souza ◽  
Carlos Roberto Bueno Júnior ◽  
Claudio de Oliveira Assumpção ◽  
...  
Keyword(s):  
Gene Polymorphisms ◽  
Performance Enhancement ◽  
Effect Sizes ◽  
Vertical Force ◽  
Mean Power ◽  
Jump Performance ◽  
Significance Level ◽  
Repetition Maximum ◽  
Before And After ◽  
Mean Power Output

ABSTRACT We aimed to investigate the influence of alpha-actinin-3 (ACTN3) R577X polymorphism on responsiveness to post-activation performance enhancement (PAPE) of countermovement jumps (CMJ) in untrained subjects. Sixteen untrained men were allocated into two groups according to their ACTN3 gene alleles: homozygous for the X allele (XX, n = 9) or homozygous for the R allele (RR, n = 7). CMJ height, mean power output and vertical force were determined twice (CMJ1 and CMJ2) in two conditions: control (CON) and potentiated (PAPE). In the CON condition, CMJ were performed before and after a 15-min rest. In the PAPE condition, CMJ were performed 15 min before and 4 min following five squats with a 5-repetition maximum (5RM) load. Different conditions were applied on separate days in a randomized order. Statistical analysis involved three-way ANOVAs to compare the differences between conditions (CON and PAPE), time (CMJ1 and CMJ2), and groups (XX and RR). Significance level considered was p < 0.05. Effect sizes were calculated as Cohen’s d. The effect sizes for changes in CMJ height for CON and following pre-activation for PAPE were 0.04 and 0.08, respectively. No significant differences were found for CMJ height between XX and RR at baseline (1.07 ± 2.54 cm e -0.82 ± 2.56 cm, respectively). No differences were found (p>0.05) in responsiveness to PAPE between the groups (XX = -0.20 ± 1.6 cm and RR = -0.81 ± 2.7 cm). We conclude that ACTN3 gene polymorphisms does not influence responsiveness to PAPE.

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 Unilateral and Bilateral Post-Activation Performance Enhancement on Jump Performance and Agility

2021 ◽  
Vol 18 (19) ◽  
pp. 10154
Author(s):  
Alejandro Escobar Hincapié ◽  
Carlos Alberto Agudelo Velásquez ◽  
Mariluz Ortiz Uribe ◽  
Camilo Andrés García Torres ◽  
Andrés Rojas Jaramillo
Keyword(s):  
Effect Size ◽  
Performance Enhancement ◽  
Vertical Jump ◽  
Effect Sizes ◽  
Training Experience ◽  
Jump Performance ◽  
Warm Up ◽  
Vertical Jumping ◽  
Different Types ◽  
Before And After

This study aimed to compare the effects of the post-activation performance enhancement (PAPE) of two different types of warm-ups, unilateral and bilateral, on the performance in vertical jumping and agility of healthy subjects with strength training experience. In the study, 17 subjects (12 men and 5 women) performed two different PAPE protocols: unilateral squat (UT) and bilateral squat (BT). The height of the subjects’ countermovement jump (CMJ) and the subjects’ time to perform the T-agility test (TAT) were measured before and after executing the PAPE warm-up. The squats were performed at a velocity of 0.59 m·s−1 with three sets of three repetitions, with a 3-min rest between sets and a 5-min rest after both uni-and bilateral PAPE warm-ups before taking the tests again. For statistical analysis, we applied ANOVA and calculated the effect size. The results showed that the PAPE for each case decreased the CMJ height but generated significant improvements in the total time taken for the T-agility test (p < 0.01); however, in both cases, the effect sizes were trivial. In conclusion, it is possible to observe that the PAPE, performed both unilaterally and bilaterally, negatively affects the performance in the vertical jump, showing moderate effect sizes. However, both PAPE protocols show performance benefits in agility tests, with a large effect size for the unilateral protocol and moderate for the bilateral protocol.

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.

Effect of training on muscle metabolism during treadmill sprinting

1989 ◽  
Vol 67 (6) ◽  
pp. 2376-2382 ◽  
Author(s):  
M. E. Nevill ◽  
L. H. Boobis ◽  
S. Brooks ◽  
C. Williams
Keyword(s):  
Vastus Lateralis ◽  
Muscle Metabolism ◽  
Plasma Norepinephrine ◽  
Sprint Training ◽  
Mean Power ◽  
Muscle Lactate ◽  
Group 4 ◽  
Before And After ◽  
Muscle Buffering Capacity ◽  
Mean Power Output

Sixteen subjects volunteered for the study and were divided into a control (4 males and 4 females) and experimental group (4 males and 4 females, who undertook 8 wk of sprint training). All subjects completed a maximal 30-s sprint on a nonmotorized treadmill and a 2-min run on a motorized treadmill at a speed designed to elicit 110% of maximum oxygen uptake (110% run) before and after the period of training. Muscle biopsies were taken from vastus lateralis at rest and immediately after exercise. The metabolic responses to the 110% run were unchanged over the 8-wk period. However, sprint training resulted in a 12% (P less than 0.05) and 6% (NS) improvement in peak and mean power output, respectively, during the 30-s sprint test. This improvement in sprint performance was accompanied by an increase in the postexercise muscle lactate (86.0 +/- 26.4 vs. 103.6 +/- 24.6 mmol/kg dry wt, P less than 0.05) and plasma norepinephrine concentrations (10.4 +/- 5.4 vs. 12.1 +/- 5.3 nmol/l, P less than 0.05) and by a decrease in the postexercise blood pH (7.17 +/- 0.11 vs. 7.09 +/- 0.11, P less than 0.05). There was, however, no change in skeletal muscle buffering capacity as measured by the homogenate technique (67.6 +/- 6.5 vs. 71.2 +/- 4.5 Slykes, NS).

Micronutrient Fortified Carbohydrate Supplementation and Speed, Agility and Power in Indian Adolescent Athletes

2017 ◽  
Vol 54 (1) ◽  
pp. 1
Author(s):  
Tessa E. Morris ◽  
Rachana Bhoite ◽  
Ritu Karwal ◽  
, Verma ◽  
, Bhavna ◽  
...  
Keyword(s):  
Intermittent Exercise ◽  
Cycle Ergometer ◽  
Adolescent Athletes ◽  
Mean Power ◽  
Wingate Anaerobic Test ◽  
Performance Impact ◽  
Treatment Groups ◽  
Before And After ◽  
The Difference ◽  
Mean Power Output

The positive performance impact of exogenous carbohydrate intake on prolonged endurance is well established. The effect on shorter duration activities has been less documented, in particular with adolescents. In this randomized, cross over study, thirty adolescent athletes (24 male and 6 female; age: 13.5 ± 1.0 yrs; height: 161.4 ± 8.1cm; weight: 50.4 ± 9.3 kg) performed the same sequence of procedures; baseline assessments, a treatment drink before and after a 45 min intermittent exercise protocol followed by post-baseline assessments. Participants were randomised to one of three blinded treatment drinks; micronutrient fortified carbohydrate (CHO), calorie-matched control (PRO) or water (WAT). The assessments involved repeated sprint and repeated agility tests (6 repetitions; 65 sec. provided to complete the repetition and recover prior to the next effort) and a repeated Wingate anaerobic test (3 x 30 sec) on a cycle ergometer. The Fatigue Index (FI) was calculated from the sprint and agility results and Mean Power Output (MPO) from the repeated Wingate results. The difference between the baseline and post-baseline results was then calculated and CHO, PRO and WAT treatment groups compared using Analysis of variance (ANOVA). No significant differences were found between speed, agility and power change from baseline results when CHO, PRO and WAT treatment groups were compared (p ≥ 0.05). Supplementation with a micronutrient fortified carbohydrate beverage does not increase repeated speed, agility or power in Indian adolescent team sport athletes.

scholarly journals The Validity of the Push Band 2.0 during Vertical Jump Performance

Sports ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 140 ◽  
Author(s):  
Jason Lake ◽  
Simon Augustus ◽  
Kieran Austin ◽  
Peter Mundy ◽  
John McMahon ◽  
...  
Keyword(s):  
Motion Capture ◽  
Vertical Jump ◽  
Force Plate ◽  
Three Dimensional ◽  
Practical Method ◽  
Force Platform ◽  
Vertical Force ◽  
Mean Power ◽  
Mean Velocity ◽  
Jump Performance

The Push Band has the potential to provide a cheap and practical method of measuring velocity and power during countermovement vertical jumping (CMJ). However, very little is known about whether it conforms to laboratory-based gold standards. The aim of this study was to assess the agreement between peak and mean velocity and power obtained from the belt-worn Push Band, and derived from three-dimensional motion capture, and vertical force from an in-ground force platform. Twenty-two volunteers performed 3 CMJ on a force platform, while a belt-worn Push Band and a motion capture system (a marker affixed to the Push Band) simultaneously recorded data that enabled peak and mean velocity and power to be calculated and then compared using ordinary least products regression. While the Push Band is reliable, it tends to overestimate peak (9–17%) and mean (24–27%) velocity, and when compared to force plate-derived peak and mean power, it tends to underestimate (40–45%) and demonstrates fixed and proportional bias. This suggests that while the Push Band may provide a useful method for measuring peak and mean velocity during the CMJ, researchers and practitioners should be mindful of its tendency to systematically overestimate and that its measures of peak and mean power should not be used.

scholarly journals Effects of aerobic exercise under different thermal conditions on human somatosensory processing

2016 ◽  
Vol 311 (4) ◽  
pp. R629-R636 ◽  
Author(s):  
Hiroki Nakata ◽  
Misaki Oshiro ◽  
Mari Namba ◽  
Manabu Shibasaki
Keyword(s):  
Aerobic Exercise ◽  
Rest Period ◽  
Thermal Conditions ◽  
Exercise Bout ◽  
Somatosensory Processing ◽  
Posterior Tibial Nerve Stimulation ◽  
Mean Power ◽  
Somatosensory Input ◽  
Before And After ◽  
Mean Power Output

The present study aimed to investigate the effects of aerobic exercise on human somatosensory processing recorded by somatosensory evoked potentials (SEPs) under temperate [TEMP, 20°C and 40% relative humidity (RH)] and hot (HOT, 35°C and 30% RH) environments. Fifteen healthy subjects performed 4 × 15-min bouts of a moderate cycling exercise [mean power output: 156.5 ± 7.7 (SE) W], with a 10-min rest period and received a posterior tibial nerve stimulation at the left ankle before and after each exercise bout; SEPs were recorded in five sessions; 1st (pre), 2nd (post-1st exercise bout), 3rd (post-2nd exercise bout), 4th (post-3rd exercise bout), and 5th (post-4th exercise bout). The peak latencies and amplitudes of the P37, N50, P60, and N70 components at Cz were evaluated. The latencies of P37, N50, P60, and N70 were significantly shorter with the repetition of aerobic exercise, and these shortened latencies were significantly greater in the HOT condition than in the TEMP condition (P37: 3rd, P < 0.05, and 5th, P < 0.01; P60: 4th, P < 0.05, and 5th, P < 0.01; N70: 4th, P < 0.05, and 5th, P < 0.001). No significant differences were observed in the amplitudes of any SEP component under either thermal condition. These results suggest that the conduction velocity of the ascending somatosensory input was accelerated by increases in body temperature, and aerobic exercise did not alter the strength of neural activity in cortical somatosensory processing.

scholarly journals The Effects of Plyometric Conditioning on Post-Activation Bench Press Performance

2020 ◽  
Vol 74 (1) ◽  
pp. 99-108 ◽  
Author(s):  
Michal Krzysztofik ◽  
Michal Wilk
Keyword(s):  
Power Output ◽  
Bench Press ◽  
Performance Enhancement ◽  
Peak Power Output ◽  
Rest Interval ◽  
Mean Power ◽  
Warm Up ◽  
Bar Velocity ◽  
Press Performance ◽  
Mean Power Output

Abstract The present study aimed to determine the effects of plyometric push-ups as a conditioning activity (CA) on high-loaded bench press performance. Two groups of resistance-trained males age (24.5 ± 2.6 years, body mass 84.8 ± 8 kg) performed one of two CA protocols: 3 sets of 5 repetitions of plyometric push-ups with a 1 min rest interval between sets (PAPE; n=12) or equal time aerobic warm-up (CONT; n=12). Four minutes after completion of the CA protocols the participants performed 3 sets of 3 repetitions of the bench press exercise at 70%1RM and 4 min rest interval between sets to assess post-activation differences in peak power output (PP), mean power output (MP), peak bar velocity (PV), and mean bar velocity (MV) between conditions. The two-way ANOVA revealed significant condition × set interaction effect for PP (p<0.01), MP (p<0.05), PV (p<0.01), and MV (p=0.02). The post hoc for condition × set interaction showed that PAPE caused a significant decrease in PP and PV for P-Set2 and P-Set3 when compared to baseline (BA). The MP and MV for the PAPE condition decreased significantly during the P-Set3 compared to BA and to P-Set1. The t-test comparisons for delta values showed significant differences between PAPE and CONT in PP for P-Set1 – BA (p<0.01), in MP for P-Set2 – P-Set1 (p<0.03) and for P-Set3 – P-Set1 (p=0.04). Furthermore, there were significant differences in PV for P-Set3 – BA; P-Set2 – P-Set1; P-Set3 – P-Set1 (p<0.01; p<0.01; p<0.02 respectively). Finally, there were significant differences in MV for P-Set1 – BA; P-Set2 – P-Set1 and P-Set3 – P-Set1 (p<0.01; p<0.01; p<0.02 respectively). This study demonstrated that plyometric push-ups lead to performance enhancement of the bench press exercise at 70%1RM. The increases in performance were observed only in the first set following the CA, while a significant decrease of these variables was registered in P-Set2 and P-Set3.

scholarly journals Relationships between Mechanical Variables in the Traditional and Close-Grip Bench Press

2017 ◽  
Vol 60 (1) ◽  
pp. 19-28 ◽  
Author(s):  
Robert G. Lockie ◽  
Samuel J. Callaghan ◽  
Matthew R. Moreno ◽  
Fabrice G. Risso ◽  
Tricia M. Liu ◽  
...  
Keyword(s):  
Peak Power ◽  
Bench Press ◽  
Effect Sizes ◽  
Upper Body ◽  
Mean Power ◽  
Repetition Maximum ◽  
Paired Samples ◽  
Force Velocity ◽  
The One

Abstract The study aim was to determine relationships between mechanical variables in the one-repetition maximum (1RM) traditional bench press (TBP) and close-grip bench press (CGBP). Twenty resistance-trained men completed a TBP and CGBP 1RM. The TBP was performed with the preferred grip; the CGBP with a grip width of 95% biacromial distance. A linear position transducer measured: lift distance and duration; work; and peak and mean power, velocity, and force. Paired samples t-tests (p < 0.05) compared the 1RM and mechanical variables for the TBP and CGBP; effect sizes (d) were also calculated. Pearson’s correlations (r; p < 0.05) computed relationships between the TBP and CGBP. 1RM, lift duration, and mean force were greater in the TBP (d = 0.30-3.20). Peak power and velocity was greater for the CGBP (d = 0.50-1.29). The 1RM TBP correlated with CGBP 1RM, power, and force (r = 0.685-0.982). TBP work correlated with CGBP 1RM, lift distance, power, force, and work (r = 0.542-0.931). TBP power correlated with CGBP 1RM, power, force, velocity, and work (r = 0.484-0.704). TBP peak and mean force related to CGBP 1RM, power, and force (r = 0.596-0.980). Due to relationships between the load, work, power, and force for the TBP and CGBP, the CGBP could provide similar strength adaptations to the TBP with long-term use. The velocity profile for the CGBP was different to that of the TBP. The CGBP could be used specifically to improve high-velocity, upper-body pushing movements.

Clinically Meaningful Change

Methodology ◽  
2019 ◽  
Vol 15 (3) ◽  
pp. 97-105
Author(s):  
Rodrigo Ferrer ◽  
Antonio Pardo
Keyword(s):  
Effect Size ◽  
False Negative ◽  
False Negative Rate ◽  
Point Of View ◽  
Skewed Distribution ◽  
Effect Sizes ◽  
False Negatives ◽  
Large Size ◽  
Before And After ◽  
Post Test

Abstract. In a recent paper, Ferrer and Pardo (2014) tested several distribution-based methods designed to assess when test scores obtained before and after an intervention reflect a statistically reliable change. However, we still do not know how these methods perform from the point of view of false negatives. For this purpose, we have simulated change scenarios (different effect sizes in a pre-post-test design) with distributions of different shapes and with different sample sizes. For each simulated scenario, we generated 1,000 samples. In each sample, we recorded the false-negative rate of the five distribution-based methods with the best performance from the point of view of the false positives. Our results have revealed unacceptable rates of false negatives even with effects of very large size, starting from 31.8% in an optimistic scenario (effect size of 2.0 and a normal distribution) to 99.9% in the worst scenario (effect size of 0.2 and a highly skewed distribution). Therefore, our results suggest that the widely used distribution-based methods must be applied with caution in a clinical context, because they need huge effect sizes to detect a true change. However, we made some considerations regarding the effect size and the cut-off points commonly used which allow us to be more precise in our estimates.

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