Effects of Different Conditioning Activities on the Sprint Performance of Elite Sprinters: A Systematic Review With Meta-Analysis.

PURPOSE: Postactivation performance enhancement (PAPE), which refers to the phenomena associated with the attainment of enhanced performance in sport-specific tasks after a conditioning activity, is an important objective of warming-up practices in many sports. This is even more relevant for sprinters, as potential increases in sprinting speed will directly influence their competitive results. This systematic review with meta-analysis evaluated the effects of different PAPE protocols (ie, using plyometrics, strength-power exercises, and resisted/assisted sprints) on the sprinting performance (ie, sprint time or sprint speed) of competitive sprinters. METHODS: Initially, 1205 records published until last December 18 were identified, using the following databases: PubMed/MEDLINE, Scopus, and Clarivate Web of Science. After removing duplicates and screening titles and abstracts, 14 high-quality studies met the inclusion criteria for the meta-analysis. RESULTS: Overall, there were no significant changes in sprint performance after implementing various types of conditioning activities (standardized mean difference [SMD] = 0.16 [95% CI, -0.02 to 0.33]; Z = 1.78; P = .08; I2 = 0%). In addition, when comparing prechanges and postchanges between experimental, control, and other conditions, no significant differences were found in sprint speed or time across all studies (SMD = 0.09 [95% CI, -0.10 to 0.28]; Z = 0.92; P = .36; I = 0%). CONCLUSIONS: Results revealed that different types of conditioning activities may not be capable of acutely enhancing the sprint speed of competitive sprinters. This aligns with previous observations indicating that sprinting is a highly stable physical capacity, a phenomenon that is even more consistent among elite sprinters. Coaches and sport scientists should collaborate to develop more efficient PAPE protocols for these highly specialized athletes, with special attention to study design and individualization, while considering their effects on acceleration versus top speed.

Impacto de ejercicios bilaterales y unilaterales en la potenciación aguda del salto horizontal en futbolistas profesionales / Impact of Bilateral and Unilateral Exercises on Acute Enhancement of Horizontal Jump Performance in Professional Soccer Player / Impacto dos Exercícios Bilaterais e Unilaterais no Aumento Agudo do Desempenho do Salto Horizontal em Jogadores Profissionais de Futebol

Resumen Objetivo: Analizar el efecto de una activación realizada a través de ejercicios de fuerza y pliometría ejecutados de forma bilateral o unilateral sobre el rendimiento en salto horizontal. Metodología: En el estudio participaron 15 futbolistas masculinos, altamente entrenados (edad, 24.7 ± 3.1 años; altura, 181.2 ± 4.7 cm; peso, 79.7 ± 3.4 kg) pertenecientes al mismo equipo, que competía en liga nacional. Su rutina de entrenamiento regular constaba de 4 sesiones y 1 partido competitivo por semana. Los participantes llevaron a cabo 1 protocolo control (CON) y 3 protocolos de activación, siguiendo un diseño contrabalanceado, basados en ejercicios específicos de fútbol (SIN), ejercicios de fuerza y pliometría ejecutados de forma bilateral (BIL) y unilateral (UNI). Después de cada protocolo los jugadores realizaron la prueba de salto horizontal (HZB). Resultados: Los resultados de la prueba ANOVA de medidas repetidas mostraron efectos positivos significativos sobre el HZB de los protocolos SIN (p<0.01; dif = 2.95(2.00)%), BIL (p<0.01; dif = 3.22(2.61) %); y UNI (p<0.01; dif = 6.80(3.40) %) con respecto a CON. Además, HZB fue, significativamente, mayor después del protocolo UNI que del SIN (p<0.01; dif = 3.74(2.62) %) y BIL (p<0.01; dif = 3.47(1.94) %). El análisis de la respuesta individual reflejó efectos positivos en HZB de los protocolos SIN, BIL y UNI respecto al CON, mientras que el 89 % de los jugadores tuvieron mejor rendimiento en HZB después de UNI que de BIL. Conclusiones: Una activación que incorpora estímulos de fuerza y pliometría ejecutados, de forma unilateral, tiene un efecto positivo mayor sobre la capacidad de salto horizontal, que una activación que involucra ejercicios generales, específicos de fútbol y de ejecución bilateral.

Abstract Objective: To analyze the effect of activation through bilateral or unilateral strength and plyometric exercises on horizontal jump performance. Methodology: The study involved 15 highly trained male soccer players (age, 24.7 ± 3.1 years; height, 181.2 ± 4.7 cm; weight, 79.7 ± 3.4 kg) from the same team competing in the national league. Their regular training routine consisted of 4 sessions and 1 competitive match per week. Participants performed 1 control protocol (CON) and 3 activation protocols following a counterbalanced design based on specific soccer exercises (SIN), bilateral (BIL), and unilateral (UNI) strength and plyometric exercises. After each protocol, players underwent the horizontal jump test (HZB). Results: The repeated measures ANOVA revealed significant positive effects on HZB for the SIN (p<0.01; diff = 2.95(2.00) %), BIL (p<0.01; diff = 3.22(2.61) %), and UNI (p<0.01; diff = 6.80(3.40) %) protocols compared to CON. Furthermore, HZB was significantly higher after the UNI protocol than after SIN (p<0.01; diff = 3.74(2.62) %) and BIL (p<0.01; diff = 3.47(1.94) %). Individual response analysis reflected positive effects on HZB for SIN, BIL, and UNI compared to CON, while 89 % of players showed better HZB performance after UNI than after BIL. Conclusions: Activation incorporating unilateral strength and plyometric stimuli has a greater positive effect on horizontal jump capacity than activation involving general, soccer-specific, and bilateral exercises.

Resumo Objetivo: Analisar o efeito da ativação por meio de exercícios de força e pliométricos bilaterais ou unilaterais no desempenho do salto horizontal. Metodologia: O estudo envolveu 15 jogadores de futebol masculinos altamente treinados (idade, 24.7 ± 3.1 anos; altura, 181.2 ± 4.7 cm; peso, 79.7 ± 3.4 kg) da mesma equipe competindo na liga nacional. Sua rotina de treinamento regular consistia em 4 sessões e 1 jogo competitivo por semana. Os participantes realizaram 1 protocolo de controle (CON) e 3 protocolos de ativação seguindo um desenho contrabalanceado com base em exercícios específicos de futebol (SIN), exercícios de força e pliométricos bilaterais (BIL) e unilaterais (UNI). Após cada protocolo, os jogadores foram submetidos ao teste de salto horizontal (HZB). Resultados: A ANOVA de medidas repetidas revelou efeitos positivos significativos no HZB para os protocolos SIN (p<0.01; diff = 2.95(2.00) %), BIL (p<0.01; diff = 3.22(2.61) %) e UNI (p<0.01; diff = 6.80(3.40) %) em comparação com CON. Além disso, o HZB foi significativamente maior após o protocolo UNI do que após SIN (p<0.01; diff = 3.74(2.62) %) e BIL (p<0.01; diff = 3.47(1.94) %). A análise de resposta individual refletiu efeitos positivos no HZB para SIN, BIL e UNI em comparação com CON, enquanto 89 % dos jogadores mostraram melhor desempenho de HZB após UNI do que após BIL. Conclusões: A ativação incorporando estímulos de força e pliométricos unilaterais tem um efeito positivo maior na capacidade de salto horizontal do que a ativação envolvendo exercícios gerais, específicos do futebol e bilaterais.

Monitoring Bar Velocity to Quantify Fatigue in Resistance Training.

We analyzed the effects of load magnitude and bar velocity variables on sensitivity to fatigue. Seventeen resistance-trained men (age=25.7±4.9 years; height=177.0±7.2 cm; body mass=77.7±12.3 kg; back-squat 1RM=145.0±33.9 kg; 1RM/body mass=1.86) participated in the study. Pre- and post-exercise changes in the mean propulsive velocity (MPV) and peak velocity (PV) in the back-squat at different intensities were compared with variations in the countermovement jump (CMJ). CMJ height decreased significantly from pre- to post-exercise (∆%=-7.5 to -10.4; p<0.01; ES=0.37 to 0.60). Bar velocity (MPV and PV) decreased across all loads (∆%=-4.0 to -12.5; p<0.01; ES=0.32 to 0.66). The decrease in performance was similar between the CMJ, MPV (40% and 80% 1RM; p=1.00), and PV (80% 1RM; p=1.00). The magnitude of reduction in CMJ performance was greater than MPV (60% 1RM; p=0.05) and PV (40% and 60% 1RM; p<0.01) at the post-exercise moment. Low systematic bias and acceptable levels of agreement were only found between CMJ and MPV at 40% and 80% 1RM (bias=0.35 to 1.59; ICC=0.51 to 0.71; CV=5.1% to 8.5%). These findings suggest that the back-squat at 40% or 80% 1RM using MPV provides optimal sensitivity to monitor fatigue through changes in bar velocity.

Acute Effects of Different Conditioning Activities on Amateur Soccer Players.

Several warm-up activities are used to prepare soccer players for training and games. However, few studies have focused on comparing different activities (strength vs. stretching) in young and amateur athletes, especially for performance improvement in explosive actions. Thus, in order to compare the effect of four conditioning activities on jump and sprint performances, 12 soccer athletes (age: 19±0.8; weight (kg): 72.8±8.0; height (cm): 180±6.7) performed four warm-up activities: strength exercise (cluster system), combined exercise, plyometric exercise, and static stretching (control). The countermovement jump (CMJ) and 30-meter run (30-m Sprint) were performed 10 min after each experimental condition. A ONE-WAY ANOVA test of repeated measures was conducted with a Tukey's post-hoc test to compare the conditions. The strength conditioning activity protocol (33.68±2.87) showed a significant difference for the CMJ from static stretching (30.96±3.16) (p>0.05). There were significant differences regarding the 30-m Sprint test between strength conditioning (4.72±0.19) and combined activities (4.71±0.21) compared to static stretching (4.84±0.21) (p>0.05). In conclusion, the combined conditioning activity and strength protocols can be chosen in warm-up activities instead of static stretching (control condition) for improved immediate sprint and jump abilities in amateur soccer players.

Speed-Related Abilities Are Similarly Improved After Sled Training Under Different Magnitudes of Velocity Loss in Highly Trained Soccer Players.

PURPOSE: We examined the effects of two 8-week resisted-sprint training programs under different magnitudes of velocity loss (VL) on the speed-related performance of highly trained soccer players. METHODS: Twenty-one soccer players (age: 25.9 [5.4] y) were randomly assigned to 1 of 2 groups: (1) the "moderate-load group," players who trained with sled loads that induced 15%VL relative to unloaded sprint velocity (n = 11); and (2) the "heavy-load group," players who trained with sled loads that induced 40% VL relative to unloaded sprint velocity (n = 10). Linear sprint (10 m), curve sprint, change-of-direction speed, resisted-sprint performance at 15% VL and 40% VL, and vertical jumping ability were tested pretraining and posttraining. A 2-way repeated-measures analysis of variance was used to test for differences between groups. In addition, percentage changes were calculated for speed-related abilities and compared with their respective coefficients of variation to determine whether individual changes in performance were greater than the test variance (ie, "true change"). RESULTS: A main effect of time was detected for 10-m sprint, curve sprint, change-of-direction speed, and 15% VL and 40% VL resisted-sprint times, with significant decreases in sprint times (P = .003, P = .004, P = .05, P = .036, and P = .019, respectively). Jump variables did not change significantly over time. There were no group-by-time interactions for any tested variable (P > .05), but the "true change" analysis revealed meaningful individual changes in both groups. CONCLUSIONS: Both moderate- and heavy-sled loading conditions may optimize the development of speed-related abilities in highly trained soccer players. Nevertheless, resisted-sprint training responses may differ meaningfully when assessed on an individual basis.

Effects of Plyometric Jump Training on the Reactive Strength Index in Healthy Individuals Across the Lifespan: A Systematic Review with Meta-analysis.

BACKGROUND: The reactive strength index (RSI) is meaningfully associated with independent markers of athletic (e.g., linear sprint speed) and neuromuscular performance [e.g., stretch-shortening cycle (SSC)]. Plyometric jump training (PJT) is particularly suitable to improve the RSI due to exercises performed in the SSC. However, no literature review has attempted to meta-analyse the large number of studies regarding the potential effects of PJT on the RSI in healthy individuals across the lifespan. OBJECTIVE: The aim of this systematic review with meta-analysis was to examine the effects of PJT on the RSI of healthy individuals across the lifespan compared with active/specific-active controls. METHODS: Three electronic databases (PubMed, Scopus, Web of Science) were searched up to May 2022. According to the PICOS approach, the eligibility criteria were: (1) healthy participants, (2) PJT interventions of ≥ 3 weeks, (3) active (e.g., athletes involved in standard training) and specific-active (e.g., individuals using heavy resistance training) control group(s), (4) a measure of jump-based RSI pre-post training, and (5) controlled studies with multi-groups in randomised and non-randomised designs. The Physiotherapy Evidence Database (PEDro) scale was used to assess the risk of bias. The random-effects model was used to compute the meta-analyses, reporting Hedges' g effect sizes (ES) with 95% confidence intervals (95% CIs). Statistical significance was set at p ≤ 0.05. Subgroup analyses were performed (chronological age; PJT duration, frequency, number of sessions, total number of jumps; randomization). A meta-regression was conducted to verify if PJT frequency, duration, and total number of sessions predicted the effects of PJT on the RSI. Certainty or confidence in the body of evidence was assessed using Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Potential adverse health effects derived from PJT were researched and reported. RESULTS: Sixty-one articles were meta-analysed, with a median PEDro score of 6.0, a low risk of bias and good methodological quality, comprising 2576 participants with an age range of 8.1-73.1 years (males, ~ 78%; aged under 18 years, ~ 60%); 42 studies included participants with a sport background (e.g., soccer, runners). The PJT duration ranged from 4 to 96 weeks, with one to three weekly exercise sessions. The RSI testing protocols involved the use of contact mats (n = 42) and force platforms (n = 19). Most studies reported RSI as mm/ms (n = 25 studies) from drop jump analysis (n = 47 studies). In general, PJT groups improved RSI compared to controls: ES = 0.54, 95% CI 0.46-0.62, p < 0.001. Training-induced RSI changes were greater (p = 0.023) for adults [i.e., age ≥ 18 years (group mean)] compared with youth. PJT was more effective with a duration of > 7 weeks versus ≤ 7 weeks, > 14 total PJT sessions versus ≤ 14 sessions, and three weekly sessions versus < three sessions (p = 0.027-0.060). Similar RSI improvements were noted after ≤ 1080 versus > 1080 total jumps, and for non-randomised versus randomised studies. Heterogeneity (I2) was low (0.0-22.2%) in nine analyses and moderate in three analyses (29.1-58.1%). According to the meta-regression, none of the analysed training variables explained the effects of PJT on RSI (p = 0.714-0.984, R2 = 0.0). The certainty of the evidence was moderate for the main analysis, and low-to-moderate across the moderator analyses. Most studies did not report soreness, pain, injury or related adverse effects related to PJT. CONCLUSIONS: The effects of PJT on the RSI were greater compared with active/specific-active controls, including traditional sport-specific training as well as alternative training interventions (e.g., high-load slow-speed resistance training). This conclusion is derived from 61 articles with low risk of bias (good methodological quality), low heterogeneity, and moderate certainty of evidence, comprising 2576 participants. PJT-related improvements on RSI were greater for adults versus youths, after > 7 training weeks versus ≤ 7 weeks, with > 14 total PJT versus ≤ 14 sessions, and with three versus < three weekly sessions.

Efeito do treinamento pliométrico de curta duração no salto vertical e velocidade de sprint em jogadores de vôlei / Effect of short duration plyometric training on vertical jump and sprint speed in volleyball players

INTRODUÇÃO: O voleibol é um esporte de ritmo acelerado que envolve projeções verticais e horizontais da bola por parte do jogador. O uso de treinamento pliométrico é um método popular para melhorar o desempenho dos jogadores. OBJETIVO: O presente estudo visa verificar o efeito de quatro semanas de treinamento pliométrico em jogadores de voleibol. MÉTODO: Estudo randomizado, controlado, de grupos paralelos. Foram triados 39 participantes para participação no estudo, dos quais 30 foram selecionados seguindo os critérios de inclusão e exclusão da pesquisa. Os critérios de inclusão foram: jogadores de voleibol na faixa etária de 18 a 24 anos, de ambos os sexos, experiência de jogo de no mínimo um ano e disponibilidade para participar. Os critérios de exclusão compreendiam jogadores com histórico de lesão nos últimos seis meses, qualquer distúrbio neurológico ou musculoesquelético e qualquer condição psicológica. Os participantes selecionados foram alocados aleatoriamente no Grupo A e Grupo B usando o método de sorteio. O Grupo A recebeu treinamento pliométrico por três dias em uma semana, e o Grupo B foi solicitado a continuar seus exercícios regulares de rotina. A duração total da intervenção foi de quatro semanas. A medida de resultado para o estudo foi a velocidade do sprint e a altura do salto vertical. A velocidade de sprint foi medida pelo teste de sprint de 20 m e a altura do salto vertical foi medida pelo teste sargent jump. A avaliação foi feita no início e no final de quatro semanas. O teste t não pareado foi usado para analisar as diferenças entre os grupos e o teste t pareado foi usado para analisar as diferenças dentro do grupo nas variáveis de resultado. RESULTADOS: O resultado do estudo mostrou uma melhora significativa na altura do salto vertical (MD= -7,133, IC 95% (-12,657,- 1,609) e nenhuma melhora significativa na velocidade do sprint quando comparações entre grupos foram feitas (MD=0,084, 95% IC (-0,177,-,345) com um tamanho de efeito de 0,75 para a altura do salto vertical. A comparação dentro do grupo foi considerada significativa apenas para a altura do salto vertical no Grupo A, e não houve melhora significativa na velocidade de sprint para ambos Grupo A e B. CONCLUSÃO: Quatro semanas de programa pliométrico é eficaz em melhorar a altura do salto vertical e não a velocidade de sprint em jogadores de voleibol.

INTRODUCTION: Volleyball is a fast-paced sport that involves vertical and horizontal projections of the ball by the player. The use of plyometric training is a popular method to enhance performance in players. OBJECTIVE: The present study aims to see the effect of short-duration plyometric training on vertical jump and sprint speed in volleyball players. METHOD: This study is a parallel group randomized controlled trial. Thirtynine participants were screened for participation in the study, of which 30 were selected following the inclusion and exclusion criteria for the study. The inclusion criteria for the study comprised of volleyball players of age group 18 to 24 years, both males and females, with playing experience of at least one year, and willing to participate. The exclusion criteria for the study included players with a history of injury in the last six months, any reported neurological or musculoskeletal disorder, and any psychological condition. The selected participants were randomly allocated to Group A and Group B using the lottery method. Group A was given plyometric training for three days a week and Group B was asked to continue their regular routine exercises and playing schedule. The total duration of the intervention was four weeks. The outcome measure for the study was sprint speed and vertical jump height. Sprint speed was measured by the 20 m sprint test, and the vertical jump height was measured by the Sargent jump test. The assessment was done at the baseline and at the end of four weeks. An unpaired t-test was used to analyze between-group differences, and paired t-test was used to analyze the within-group differences in the outcome variables. The significance level was set as p<0.05. RESULTS: The result of the study showed a significant improvement in vertical jump height (MD= -7.133, 95% CI-12.657, -1.609) and no significant improvement in sprint speed when between-group comparisons were made (MD=0.084, 95%CI -0.177,-.345) with an effect size of 0.75 for vertical jump height. The within-group comparison was found significant only for vertical jump height in Group A, and there was no significant improvement was found in sprint speed for both Group A and B. FINAL CONSIDERATIONS: The short-duration plyometric training is effective in improving the vertical jump height and not the sprint speed in volleyball players. The specificity of plyometric training is important for optimal improvement in sports performance.

Can plyometric training change the pacing behaviour during 10-km running?

The effects of plyometric training (PT) on middle- and long-distance running performances are well established. However, its influence on pacing behaviour is still unclear. The aim of this study was to evaluate the effects of PT on pacing behaviour. In addition, verify whether the adaptations induced by PT would change ratings of perceived exertion (RPE) and/or affective feelings during the race. Twenty-eight male runners were assigned to two groups: control (C) and PT. PT held two weekly PT sessions for eight weeks. Drop jump (DJ) performance, 10-km running performance, pacing behaviour, RPE and affective feelings, VO2peak, ventilatory thresholds (VT1 and VT2), peak treadmill speed (PTS), and running economy (RE) were measured. For group comparisons, a mixed model analysis for repeated measures, effect size (ES) and 90% confidence interval (90% CI) were calculated for all dependent variables. Significant differences pre-to-post was observed for PT group in DP (7.2%; p ≤ 0.01; ES = 0.56 (0.28-0.85)) and RE (4.5%; p ≤ 0.05; ES = -0.52 ((-0.73 to -0.31)) without changes in pacing behaviour. While PT was effective for improving DJ and RE, there is no evidence that pacing behaviour, RPE or affective feelings are directly affected by these adaptations during a 10-km time trial run.

Weightlifting derivatives vs. plyometric exercises: Effects on unloaded and loaded vertical jumps and sprint performance.

The aim of this study was to compare the effects of weightlifting derivatives (WL) and plyometric exercises (PLYO) on unloaded and loaded vertical jumps and sprint performance. Initially, 45 resistance-trained men underwent a 4-week WL learning period. Then, the participants were randomly assigned to 1 of 3 groups (WL (n = 15), PLYO (n = 15), and control group (CG) (n = 15)) and followed a training period of 8 weeks. The WL group performed exercises to stimulate the entire force-velocity profile, while the PLYO group performed exercises with an emphasis in vertical- and horizontal-oriented. The CG did not perform any exercise. Pre- and post-training assessments included peak power output (PPO) and jump height (JH) in the squat jump (SJ), countermovement jump (CMJ), CMJ with 60% and 80% of the body mass (CMJ60% and CMJ80%, respectively), and mean sprinting speeds over 5, 10, 20, and 30 m distances. From pre- to post-training, PLYO significantly increased (p≤0.05) PPO and JH in the SJ, PPO during CMJ, and PPO and JH in the CMJ60%; however, no significant changes were observed in JH during CMJ, and PPO and JH in the CMJ80%. For WL and CG, no significant changes were observed in the unloaded and loaded vertical jumps variables. PLYO also resulted in significant improvements (p≤0.05) for 5, 10, and 20 m sprint speeds, but not for 30 m. For WL and CG, no significant changes were observed for all sprint speeds. In conclusion, these data demonstrate that PLYO was more effective than a technically-oriented WL program to improve unloaded and loaded vertical jumps and sprint performance.

Relationship between infrared thermography and muscle damage markers in physically active men after plyometric exercise.

Plyometric training has been used in several sports and fitness programs to improve jumping ability and explosive strength, both in individual and team sports. Eccentric muscle actions, such as those performed during plyometric jumps, induce muscle damage and consequently a rise in skin temperature (Tsk). Thus, the purpose of this study is to assess the response of infrared thermography measurement as an indirect marker of muscle damage after a protocol of plyometric jumps in physically active subjects. Therefore, for the aim of this study ten male subjects with no previous experience in plyometric training participated in the research (age 22.5 ± 3.3 years, weight 71.7 ± 11.0 kg, height 171.1 ± 5.3 cm, and fat mass 15.5 ± 4.7%). To assess the muscle damage, countermovement jump (CMJ), creatine kinase (CK), delayed-onset muscle soreness (DOMS) and infrared thermography (IRT) were measured at 24, 48, and 72 h after plyometric exercise. The acute exercise protocol of plyometric jumps induced muscle damage, as shown by the CK and DOMS (24 and 48 h, p < 0.05) but no statistical difference was shown between the moments analyzed in Tsk (warm zone). Nevertheless, when comparing baseline to 48h, a moderate effect was found in the Tsk (warm zone) for anterior right thigh (ES = 1.1) and posterior left thigh (ES = 0.9) and large effect was found for anterior left thigh (ES = 1.4) and posterior right thigh (ES = 1.3). A moderate effect in the Tsk (warm zone) was found for posterior right and left thigh (ES = 0.9 and ES = 1.1, respectively) when comparing baseline to 72h of IRT. These results suggest that a plyometric jumping session alters CK and DOMS, as well as the thigh's skin temperature in an evident way, bringing up a possible relation with markers of muscle damage.

Plyometric exercise enhances twitch contractile properties but fails to improve voluntary rate of torque development in highly trained sprint athletes.

Purpose: The objective of this study was to evaluate a plyometric conditioning activity (3 sets of 5 countermovement jumps, [CA]) for twitch properties and voluntary knee extension. Methods: After a familiarization session, fourteen highly trained sprint athletes, 12 men (23.25 ± 7.17 years) and 2 women (23.0 ± 2.8 years) performed 2 experiments, each in a randomized order (crossover design). In one experiment, the time-course of twitch contractile properties was evaluated with and without the previous CA at 2, min intervals to 10 min of recovery. In the second session, maximal voluntary knee extension was evaluated at the same recovery intervals, for control and experimental condition in random order. Results: Mixed-model ANOVA with Bonferroni post-hoc revealed significant differences between pre-test and 2 min (p < 0.01, ES = 0.42) and 4 min (p < 0.01, ES = 0.20) for peak twitch torque of quadriceps femoris muscles confirming postactivation potentiation [PAP] at these times. Twitch rate of torque development (RTD) was significantly greater than pre-test value only at 2 min (p < 0.01, ES = 0.58) after the CA. Twitch contraction time and ½ relaxation time were not significantly difference from pre-test values after the CA (p > 0.05). No significant difference was observed for voluntary RTD following CA. Conclusion: The plyometric CA increased twitch peak torque and RTD consistent with PAP; however, there was no effect of CA on voluntary RTD of knee extension at any time after the plyometric CA. Even with PAP confirmed, we observed that the CA fails to improve isometric RTD of quadriceps femoris muscles. HighlightsA plyometric CA significantly increased twitch peak torque (at 2 and 4 min) and twitch rate of torque development (at 2 min) of quadriceps femoris muscles, indicating postactivation potentiation (PAP).No effect was observed for twitch contraction time and ½ relaxation time after the CA.No improvement was observed on voluntary rate of torque development evaluated at the same time intervals.

Effects of 4 Weeks of Active Exergames Training on Muscular Fitness in Elderly Women.

ABSTRACT: Gallardo-Meza, C, Simon, K, Bustamante-Ara, N, Ramirez-Campillo, R, García-Pinillos, F, Keogh, JWL, and Izquierdo, M. Effects of 4 weeks of active exergames training on muscular fitness in elderly women. J Strength Cond Res 36(2): 427-432, 2022-To analyze the effects of 4 weeks of an active exergames training program on muscular fitness in older women, 2 groups of community dwelling physically active subjects were formed by block-design randomization. One was deemed the control group (CG, n = 37; age 68.1 ± 3.3 years), and a second group completed 4 weeks of an active exergames training program (ExG, n = 35; age, 69.2 ± 3.7 years). Training included active exergames (Wii Fit Plus) performed on the Wii Balanceboard, 2 sessions per week. The exergames required mainly balance-related movements, such as leaning forward, leftward, and rightward, also requiring isometric squat positions and explosive leg extension. A supervisor-to-subject ratio method of 2:1 was used. An intensity-based individual progressive overload was applied. There were no significant (all p > 0.05, d = 0.01-0.07) baseline differences between-groups for all dependent variables. For the ExG, significant improvements were observed in static balance right leg test (Δ75.5%, d = 0.89), static balance left leg (Δ33.7%, d = 0.57), timed up-and-go test (Δ14.8%, d = 0.85) and sit-to-stand velocity test (Δ83.8%, d = 1.62). For the control group, trivial to small decrements in performance were observed across all tests (Δ -2.1 to -8.4%, d = -0.08 to 0.32). Group × time interactions were observed for the static balance right and left leg, timed up-and-go test, and the mean velocity achieved in the 5-repetition sit-to-stand test (all p < 0.001; d = 0.33-0.60). In conclusion, exergames training improves muscular fitness in older women. These results should be considered when designing appropriate and better exercise training programs for older women.

Phototherapy Improves Muscle Recovery and Does Not Impair Repeated Bout Effect in Plyometric Exercise.

ABSTRACT: Padoin, S, Zeffa, AC, Molina Corrêa, JC, de Angelis, TR, Moreira, TB, Barazetti, LK, and de Paula Ramos, S. Phototherapy improves muscle recovery and does not impair repeated bout effect in plyometric exercise. J Strength Cond Res 36(12): 3301-3310, 2022-The effects of photobiomodulation with red (630 nm) and near-infrared (940 nm) light wavelengths were investigated on the inhibition of exercise-induced muscle damage (EIMD) and adaptation to the repeated bout effect (RBE). Twenty-eight healthy men were randomized to receive light-emitting diode therapy (LEDT) at 630 nm (4.6 J·cm -2 , 97 J energy), LEDT at 940 nm (4.6 J·cm -2 , 114 J), or placebo. After LEDT or placebo treatment, subjects performed 100 drop-jumps (5 sets of 20 repetitions). Creatine kinase, delayed-onset muscle soreness (DOMS), countermovement jump (CMJ), and squat jump (SJ) were assessed before, immediately after, and 24, 48, and 72 hours after the bout. After 14 days, the subjects were submitted to the same plyometric exercise, without LEDT, and were evaluated again. Creatine kinase levels increased significantly 72 hours after the first bout in the placebo group in relation to the LEDT 940-nm group ( P < 0.01). The LEDT 630-nm group showed a significant increase in SJ at 24 hours ( P < 0.05), whereas, at 48 hours, the LEDT 940 nm showed a significant increase compared with the placebo group ( P < 0.05). The 2-way analysis of variance revealed an effect for treatment in the SJ ( F = 7.12; P = 0.001). No differences were found between groups for DOMS and CMJ after the first bout. After the second bout of exercise, there was no effect of treatment. The results suggest that treatment with LEDT 630 nm and LEDT 940 nm before eccentric exercise attenuates EIMD without impairing RBE.

Effect of varied plyometric training in land and aquatic medium on anaerobic power of athletes / Efeito do treinamento pliométrico variado em meio terrestre e aquático na potência anaeróbia de atletas

ABSTRACT The aim of the present study was to find out the effect of varied plyometric training (land plyometric training, aqua plyometric training and weighted vest aqua-plyometric training) on anaerobic power of school athletes. A total of forty eight (n= 48) district level school athletes were randomly selected. All the subjects were divided into four equal groups: i) land plyometric training group (n=12), ii) aqua plyometric training group (n=12), iii) aqua-plyometric training with weighted vest group (n=12) and iv) control group (n=12). The varied plyometric training was intervened for fourteen weeks in the respective training groups. In the present study, anaerobic power was considered as the dependent variable, and it was measured by Margaria-Kalamen power test. To draw statistical inferences on anaerobic power among the groups in pre and post intervention conditions, ANCOVA was used, followed by Tukey's LSD post-hoc test. The significance of the means was tested at the 0.05 level. Different plyometric training groups improved significantly with respect to the control group in anaerobic power. Therefore, various plyometric training was found as an effective means for developing anaerobic power. A significant difference was also observed between the aqua-plyometric training with weighted vest group and land plyometric training group in anaerobic power. However, rest of the experimental groups didn't differ significantly. Aqua-plyometric training with weighted vest is a more effective training method than land plyometric training for improving the anaerobic power of the school athletes.

RESUMO O objetivo do presente estudo foi descobrir o efeito do treinamento pliométrico variado (treinamento pliométrico terrestre, treinamento aquapliométrico e treinamento aquapliométrico com colete ponderado) na potência anaeróbica de atletas escolares. Um total de quarenta e oito (n= 48) atletas escolares de nível distrital foram selecionados aleatoriamente. Todos os sujeitos foram divididos em quatro grupos iguais: i) grupo treinamento pliométrico terrestre (n=12), ii) grupo treinamento aquapliométrico (n=12), iii) grupo treinamento aquapliométrico com colete ponderado (n=12) e iv) grupo controle (n=12). O treino pliométrico variado foi intervencionado durante quatorze semanas nos respectivos grupos de treino. No presente estudo, a potência anaeróbia foi considerada como variável dependente e foi mensurada pelo teste de potência de Margaria-Kalamen. Para fazer inferências estatísticas sobre a potência anaeróbica entre os grupos nas condições pré e pós-intervenção, foi utilizada a ANCOVA, seguida do teste post-hoc de Tukey LSD. A significância das médias foi testada no nível 0,05. Diferentes grupos de treinamento pliométrico melhoraram significativamente em relação ao grupo controle na potência anaeróbica. Portanto, vários treinamentos pliométricos foram encontrados como um meio eficaz para o desenvolvimento da potência anaeróbica. Uma diferença significativa também foi observada entre o grupo de treinamento aquapliométrico com colete ponderado e o grupo de treinamento pliométrico terrestre na potência anaeróbica. No entanto, o resto dos grupos experimentais não diferiram significativamente. O treinamento aquapliométrico com colete ponderado é um método de treinamento mais eficaz do que o treinamento pliométrico terrestre para melhorar a potência anaeróbica dos atletas escolares.

Effects of Plyometric Jump Training on Electromyographic Activity and Its Relationship to Strength and Jump Performance in Healthy Trained and Untrained Populations: A Systematic Review of Randomized Controlled Trials.

ABSTRACT: Ramirez-Campillo, R, Garcia-Pinillos, F, Chaabene, H, Moran, J, Behm, DG, and Granacher, U. Effects of plyometric jump training on electromyographic activity and its relationship to strength and jump performance in healthy trained and untrained populations: a systematic review of randomized controlled trials. J Strength Cond Res 35(7): 2053-2065, 2021-This systematic review analyzed the effects of plyometric jump training (PJT) on muscle activation assessed with surface electromyography during the performance of strength and jumping tasks in healthy populations across the lifespan. A systematic literature search was conducted in the electronic databases PubMed/MEDLINE, Web of Science, and SCOPUS. Only randomized controlled studies were eligible to be included in this study. Our search identified 17 studies comprising 23 experimental groups and 266 subjects aged 13-73 years, which were eligible for inclusion. The included studies achieved a median Physiotherapy Evidence Database score of 6. No injuries were reported among the included studies. Significant PJT-related improvements were reported in 7 of 10 studies and in 6 of 10 studies for measures of muscle activation during the performance of strength and jumping tasks, respectively. Moreover, a secondary correlational analysis showed significant positive relationships (r = 0.86; p = 0.012; r2 = 0.74) between changes in muscle activation and changes in jump performance. However, from the total number (n = 287) of muscle activation response variables analyzed for strength and jumping tasks, ∼80% (n = 226) were reported as nonsignificant when compared with a control condition. In conclusion, PJT may improve muscle activation during the performance of strength and jumping tasks. However, conflicting results were observed probably arising from (a) studies that incorporated a large number of outcomes with reduced sensitivity to PJT, (b) methodological limitations associated to muscle activation measurement during strength and jumping tasks, and (c) limitations associated with PJT prescription. Future studies in this field should strive to solve these methodological shortcomings.

Effects of Progressed and Nonprogressed Volume-Based Overload Plyometric Training on Components of Physical Fitness and Body Composition Variables in Youth Male Basketball Players.

ABSTRACT: Palma-Muñoz, I, Ramírez-Campillo, R, Azocar-Gallardo, J, Álvarez, C, Asadi, A, Moran, J, and Chaabene, H. Effects of progressed and nonprogressed volume-based overload plyometric training on components of physical fitness and body composition variables in youth male basketball players. J Strength Cond Res 35(6): 1642-1649, 2021-This study examined the effect of 6 weeks of progressed and nonprogressed volume-based overload plyometric training (PT) on components of physical fitness and body composition measures in young male basketball players, compared with an active control group. Subjects were randomly assigned to a progressed PT (PPT, n = 7; age = 14.6 ± 1.1 years), a non-PPT (NPPT, n = 8, age = 13.8 ± 2.0 years), or a control group (CG, n = 7, age = 14.0 ± 2.0 years). Before and after training, body composition measures (muscle mass and fat mass), countermovement jump with arms (CMJA) and countermovement jump without arms (CMJ), horizontal bilateral (HCMJ) and unilateral jump with right leg (RJ) and left leg (LJ), 20-cm drop jump (DJ20), sprint speed (10 m sprint), and change of direction speed (CODS [i.e., T-test]) were tested. Significant effects of time were observed for muscle and fat mass, all jump measures, and CODS (all p < 0.01; d = 0.37-0.83). Significant training group × time interactions were observed for all jump measures (all p < 0.05; d = 0.24-0.41). Post hoc analyses revealed significant pre-post performance improvements for the PPT (RJ and LJ: ∆18.6%, d = 0.8 and ∆22.7%, d = 0.9, respectively; HCMJ: ∆16.4%, d = 0.8; CMJ: ∆22.4%, d = 0.7; CMJA: ∆23.3%, d = 0.7; and DJ20: ∆39.7%, d = 1.1) and for the NPPT group (LJ: ∆14.1%, d = 0.4; DJ20: ∆32.9%, d = 0.8) with greater changes after PPT compared with NPPT for all jump measures (all p < 0.05; d = 0.21-0.81). The training efficiency was greater (p < 0.05; d = 0.22) after PPT (0.015% per jump) compared with NPPT (0.0053% per-jump). The PPT induced larger performance improvements on measures of physical fitness as compared to NPPT. Therefore, in-season progressive volume-based overload PT in young male basketball players is recommended.

Effects of jump training on physical fitness and athletic performance in endurance runners: A meta-analysis.

This systematic review and meta-analysis aimed to assess the effects of jump training (JT) on measures of physical fitness and athletic performances in endurance runners. Controlled studies which involved healthy endurance runners, of any age and sex, were considered. A random-effects model was used to calculate effect sizes (ES; Hedge's g). Means and standard deviations of outcomes were converted to ES with alongside 95% confidence intervals (95%CI). Twenty-one moderate-to-high quality studies were included in the meta-analysis, and these included 511 participants. The main analyses revealed a significant moderate improvement in time-trial performance (i.e. distances between 2.0 and 5.0 km; ES = 0.88), without enhancements in maximal oxygen consumption (VO2max), velocity at VO2max, velocity at submaximal lactate levels, heart rate at submaximal velocities, stride rate at submaximal velocities, stiffness, total body mass or maximal strength performance. However, significant small-to-moderate improvements were noted for jump performance, rate of force development, sprint performance, reactive strength, and running economy (ES = 0.36-0.73; p < 0.001 to 0.031; I2 = 0.0% to 49.3%). JT is effective in improving physical fitness and athletic performance in endurance runners. Improvements in time-trial performance after JT may be mediated through improvements in force generating capabilities and running economy.

Effects of Plyometric Jump Training on Repeated Sprint Ability in Athletes: A Systematic Review and Meta-Analysis.

BACKGROUND: There is a growing body of research examining the effects of plyometric jump training (PJT) on repeated sprint ability (RSA) in athletes. However, available studies produced conflicting findings and the literature has not yet been systematically reviewed. Therefore, the effects of PJT on RSA indices remain unclear. OBJECTIVE: To explore the effects of PJT on RSA in athletes. METHODS: Searches for this review were conducted in four databases. We included studies that satisfied the following criteria: (1) examined the effects of a PJT exercise intervention on measures of RSA; (2) included athletes as study participants, with no restriction for sport practiced, age or sex; and (3) included a control group. The random-effects model was used for the meta-analyses. The methodological quality of the included studies was assessed using the PEDro checklist. RESULTS: From 6367 search records initially identified, 13 studies with a total of 16 training groups (n = 198) and 13 control groups (n = 158) were eligible for meta-analysis. There was a significant effect of PJT on RSA best sprint (ES = 0.75; p = 0.002) and RSA mean sprint (ES = 0.36; p = 0.045) performance. We did not find a significant difference between control and PJT for RSA fatigue resistance (ES = 0.16; p = 0.401). The included studies were classified as being of "moderate" or "high" methodological quality. Among the 13 included studies, none reported injury or any other adverse events. CONCLUSION: PJT improves RSA best and mean performance in athletes, while there were no significant differences between control and PJT for RSA fatigue resistance. Improvements in RSA in response to PJT are likely due to neuro-mechanical factors (e.g., strength, muscle activation and coordination) that affect actual sprint performance rather than the ability to recover between sprinting efforts.

Curve Sprint in Elite Female Soccer Players: Relationship with Linear Sprint and Jump Performance.

The aim of this study was to examine the associations between linear sprint, curve sprint (CS), change of direction (COD) speed, and jump performance in a sample of 17 professional female soccer players. All athletes performed squat and countermovement jumps, single leg horizontal triple jumps, 17 m linear sprints, CS tests, and a 17 m Zigzag COD test. A Pearson product-moment test was performed to determine the relationships among the assessed variables. The significance level was set at p < 0.05. Nearly perfect associations (r > 0.9) were found between linear and CS velocities. Players faster in linear sprints and CS exhibited greater COD deficits. No significant associations were found between COD deficit and either body mass or sprint momentum. Jumping ability was significantly correlated with linear sprint and CS performance, but not to COD performance. These findings may be used by coaches and practitioners to guide testing and training prescriptions in this population. The associations observed here suggest that training methods designed to improve linear sprint and CS velocities may benefit from the implementation of vertically and horizontally oriented plyometric exercises.

Treinamento pliométrico de membros superiores e inferiores em 5 semanas melhora desempenho físico de estudantes de educação física / Pliometric training in 5 weeks improves physical performance of physical education students: a pilot study

: Este estudo investigou o impacto de 5 semanas de treinamento pliométrico em membros superiores e inferiores sobre o desempenho físico em estudantes de Educação Física. Foram recrutados 16 estudantes do sexo masculino de 18 a 23 anos divididos em 2 grupos (Controle e Treino). O grupo Treino foi submetido ao treinamento pliométrico de membros superiores e inferiores por 5 semanas com 3 sessões/semana de 30-40 minutos/sessão, composta de 10 exercícios de braço e perna (10-20 repetições/exercício). Antes e imediatamente após o programa de treinamento pliométrico, os indivíduos foram avaliados por parâmetros antropométricos (peso, estatura, índice de massa corporal e percentual de gordura), nível de flexibilidade e desempenho físico (forças de toque e de ataque, salto vertical, sprint de 20 m e agilidade). Dados de flexibilidade e desempenho físico foram avaliados por análise de covariância (ANCOVA), além da correlação de Pearson entre as variáveis de desempenho físico após 5 semanas de treinamento. O grupo Treino exibiu maior ganho de desempenho no salto vertical quando comparado ao grupo Controle (p< 0,05). Todavia, não foi observada diferença significativa entre os grupos Treino e Controle nos ganhos de força de toque e de ataque, no desempenho do teste de sprint de 20 m, no teste de agilidade e de flexibilidade (p> 0,05). Houve correlação positiva entre os testes de forças de toque e de ataque com o salto vertical (p< 0,001, r= 0,633; e p< 0,001, r= 0,639; respectivamente), como também correlação dos testes salto vertical com os testes de velocidade (p< 0,001, r= -0,768) e agilidade (p< 0,002, r= -0,537) após o treinamento. Conclui-se que 5 semanas de treinamento pliométrico de membros superiores e inferiores exibiram melhora no desempenho do salto vertical de estudantes de Educação Física, bem como observou-se correlação entre os parâmetros neuromusculares anaeróbicos de membros inferiores e superiores após o período de treinamento.(AU)

This study investigated the impact of 5 weeks of plyometric training on upper and lower limbs on physical performance parameters in Physical Education students. Sixteen male college students aged 18 to 23 years were divided into 2 groups (Control and Training). The Training group was submitted to 5 weeks of plyometric training for upper and lower limbs, with 3 sessions per week for 30-40 minutes per session. Training sessions consisted of 10 arm and leg exercises (10-20 repetitions per exercise). Anthropometric parameters (weight, height, body mass index and body fat percentage), level of flexibility and physical performance (touch and attack strength, vertical jump, 20m sprint, agility) were assessed before and immediately after the plyometric training program. Flexibility and physical performance data were assessed by covariance analysis (ANCOVA), in addition to Pearson's correlation among physical performance parameters after 5 weeks of training. The Training group showed a greater gain in the vertical jump performance when compared to the Control group. However, no significant difference was observed between the Training and Control groups for touch and attack strength gains, for 20 m sprint performance gains, and for agility and flexibility test gains. There was a positive correlation between the tests of touch and attack strengths with vertical jump performance. There was also positive correlation between touch and attack strength with vertical jump (p< 0.001, r= 0.633; e p< 0,001, r= 0.639; respectively), and between vertical jump performance and 20m sprint performance (p< 0.001, r= -0,768) and agility test after training (p< 0.002, r= -0,537). It is concluded that 5 weeks of plyometric training for upper and lower limbs showed improvement in the vertical jump performance in Physical Education students. There was also a correlation between the anaerobic neuromuscular parameters of lower and upper limbs after the training period.(AU)