Effects of Postactivation Performance Enhancement on the Vertical Jump in High-Level Volleyball Athletes

Post-activation performance enhancement (PAPE) protocols do not further increase jumping performance beyond warm-up effects: findings from three acute randomized crossover trials

Introduction: Post-activation performance enhancement (PAPE) cannot be clearly distinguished from and may be explained in large by warm-up effects. To disentangle PAPE from a systemic warm-up effect, we conducted three randomized crossover trials (RCT). Methods: Each RCT consisted of a familiarization/one-repetition-maximum (1RM) assessment session followed by two interventional sessions (random order). In Study I, 18 participants (age: 26 ± 4 years; height: 1.84 ± 0.06 m; mass: 83.7 ± 8.7 kg; Squat-1RM: 146 ± 19 kg) performed either a 3-s isometric squat at 130%1RM or a 6-s isometric squat at 65%1RM. In Study II, 28 participants (11 female; age: 23 ± 3 years; height: 1.77 ± 0.08 m; mass: 76.5 ± 10.4 kg; Squat-1RM: 109 ± 38 kg) completed either Squat (3 × 3 repetitions, 85%1RM) or local electromyostimulation of the quadriceps muscle (85% of individual pain threshold). In Study III, 20 participants (6 female, age: 25.0 ± 3.5 years, mass: 78.5 ± 15.8 kg, height: 1.75 ± 0.08 m; SQ-1RM: 114 ± 33 kg, chest-press-1RM: 74 ± 29 kg) performed either squats or chest press (4 repetitions, 80%1RM). Counter-Movement-Jump height (CMJ) was assessed after a general (PRE) and/or muscle-specific warm-up (POST_WU) and for up to 11 min after the PAPE protocols. To identify possible differences in CMJ between the experimental conditions, mixed-design ANOVA models were used for each study individually, with condition and time modelled as fixed effects, while participants were included as a random effect blocking factor. The level of statistical significance was set at α = 5%. Results: In studies I and II, significant effects for time (p < 0.05, ωp 2 = 0.06 and p < 0.001, ωp 2 = 0.43) were found with the highest CMJ compared to all other time points at PRE (≤8.2 ± 4.6%, standardized mean difference: ≤0.39), regardless of condition. In study III, no significant effects were observed. Discussion: Thus, PAPE protocols do not further improve jumping performance compared to a general and muscle-specific traditional warm-up. Prior to tasks requiring explosive strength, general and sport-specific warm-up strategies should be used.

Acute Effects of Loaded and Unloaded Whole-Body Vibration on Vertical Jump Performance in Karate Athletes

We investigated the acute effects of different whole-body vibration (WBV) interventions on the jump height of highly trained karate practitioners. Fifteen male karate club athletes (age: 20.0 ± 3.8 years; stature: 177.3 ± 4.7 cm; body mass: 76.9 ± 11.2 kg; % body fat: 9.2 ± 4.3) performed six randomized interventions: [a] static half-squat (SHS); [b] SHS with external loads at 30% of the body weight (SHS + 30%BW); [c] WBV at frequency (f) 25 Hz, and 2 mm amplitude (A) (WBV 25/2); [d] WBV 25/2 with external loads of 30% of the body weight (WBV 25/2 + 30% BW); [e] WBV at f = 50 Hz, and A = 4 mm (WBV 50/4), and [f] WBV 50/4 with external loads of 30% of the body weight (WBV 50/4 + 30% BW). Each intervention was performed for 5 sets at 60 s/set, with a rest interval of 30 s between sets. Countermovement jump (CMJ) data were collected at 2, 4, 6, 8 and 10 min after each preconditioning intervention. Two-way repeated-measures ANOVA revealed a non-significant main effect of intervention [F(5, 10) = 1.44, η2 = 0.42, p = 0.29)] and a significant main effect of the rest interval [F(4, 11) = 3.51, η2 = 0.56, p = 0.04)] on CMJ height. A rest interval of 4 min resulted in significantly higher CMJ values than a rest interval of 2 min (p = 0.031). In conclusion, utilizing a 4-min rest interval irrespective of the intervention schemes may have potential for enhancing jumping performance among highly trained karate athletes.

Effects of Sand Surface Plyometric and Sprint Training on Physical and Technical Skill Performance in Beach Handball Players

This study compared the effects of a 6-week combined plyometric and sprint-training program on the sand to regular preseason training, on the athletic performance and technical actions of beach handball (BH) players. Athletes were randomly assigned either to the control (CG, n = 12; BH training only) or the experimental group (EG, n = 12; plyometric + sprint + BH training). Assessments conducted before and after the training period included a squat jump, a countermovement jump, the Abalakov jump, a 15-m sprint, a modified Course-Navette endurance test, and four sport-specific BH throwing speed tests: a standing penalty throw, a 3-step running throw, a jump throw, and a 360º jump throw. The training intervention enhanced all athletic performance measures (all, p < 0.05). In contrast, the only improvement in the CG included endurance performance (p< 0.05). Significant time-group differences were noted in favor of the EG compared to the CG (p< 0.05) in the squat jump, the countermovement jump, the Abalakov jump, the jump throw velocity and 360º jump throw velocity. In conclusion, compared to BH regular training, 6 weeks of sand surface preseason plyometric and sprint training combined with regular BH training induced greater improvements in athletic performance and specific skills in BH players.

Impact of active intra-complex rest intervals on post-back squat versus hip thrust jumping potentiation

This study investigated the impact of active rest intervals within a lower body complex training session on post-activation performance enhancement (PAPE) response in amateur soccer players. Twelve soccer players took part in four different experimental conditions. These sessions included 2 sets of lower body complex-paired exercises, each involving 3 repetitions of either back squats or hip thrusts at 90% one-repetition maximum (1RM) as a conditioning activity paired with a broad jump and countermovement jump. Between those exercises in active intra-complex rest interval conditions, participants were performing 8 repetitions of bench press at 75%1RM or, in passive intra-complex rest interval conditions, rested while seated. A significant main effect of a set to increase broad jump length (p = 0.002), countermovement jump height (p = 0.002), and modified reactive strength index (p = 0.005) was revealed, without any significant differences between conditions. Post-hoc comparisons showed a significant increase in broad jump length from baseline to Set-2 (231 ± 13 vs. 234 ± 13 cm; p = 0.003; ES = 0.22). On the other hand, countermovement jump height and modified reactive strength index significantly increased from baseline to Set-1 (34.4 ± 3.6 vs. 35.6 ± 3.9 cm; p = 0.027; ES = 0.31 and 0.4 ± 0.05 vs. 0.45 ± 0.09; p = 0.005; ES = 0.66). Results of this study showed that to sustain a high training density, sports practitioners may incorporate upper body exercises within the intra-complex rest interval during lower limb complex training sessions and still elicit a significant PAPE effect.

Kinematic analysis of countermovement jump performance in response to immediate neuromuscular electrical stimulation

The purpose of this study was to examine the effect of neuromuscular electrical stimulation (NMES) immediate intervention training on the countermovement jump (CMJ) height and to explore kinematic differences in the CMJ at each instant. A total of 15 male students who had never received electrical stimulation were randomly selected as the research participants. In the first test, the CMJ performance was completed with an all-out effort. The second experiment was best performed immediately to complete the CMJ operation after NMES for 30 min. Both experiments used a high-speed camera optical capture system to collect kinematic data. The results of this experiment revealed that after im-mediate NMES training, neuromuscular activation causes post-activation potentiation, which increases the height of the center of gravity of the CMJ and affects the angular velocity of the hip joint, the velocity and acceleration of the thigh and the shank and the velocity of the soles of the feet. The use of NMES interventional training based on the improvement of technical movements and physical exercises is recommended in the future.

Acute Effects of Isometric Conditioning Activity on the Viscoelastic Properties of Muscles and Sprint and Jumping Performance in Handball Players

ABSTRACT

Krzysztofik, M, Spieszny, M, Trybulski, R, Wilk, M, Pisz, A, Kolinger, D, Filip-Stachnik, A, and Stastny, P. Acute effects of isometric conditioning activity on the viscoelastic properties of muscles and sprint and jumping performance in handball players. J Strength Cond Res 37(7): 1486-1494, 2023-The effects of conditioning activity (CA) on muscle stiffness are currently unknown, suggesting that maximum CA effort can increase or decrease the stiffness of involved muscle groups. Therefore, this study aimed to investigate the effect of maximal isometric half-squats on the viscoelastic properties of muscles and postactivation performance enhancement (PAPE) in sprints and jumps. Twelve handball players underwent a standard warm-up and baseline assessment of muscle stiffness and tone of vastus lateralis and gastrocnemius medialis muscle, followed by 20-m sprint with intermediate measures at 5 and 10 m and countermovement jump. The PAPE was assessed by repeating the tests (at 4th, 8th, and 12th minute post-CA) after a CA protocol consisting of 3 sets of 3-second maximal isometric half-squats (EXP) or a control condition (CTRL) without any CA. The vastus lateralis stiffness in the 4th and 12th minute and muscle tone in the 4th minute post-CA significantly decreased compared with baseline ( p = 0.041, ES = 0.57; p = 0.013, ES = 0.52; p = 0.004, ES = 0.81, respectively) in the EXP condition. The 20-m sprint time significantly decreased at all post-CA time points compared with the baseline for the EXP condition ( p < 0.033) and the after values in the CTRL condition ( p < 0.036). In comparison to baseline, the 10-m sprint time decreased in the eighth minute post-CA ( p = 0.021; ES = 0.82) in the EXP condition. Moreover, it was significantly lower at the 8th and 12th minute post-CA ( p = 0.038; ES = 0.71 and p = 0.005; ES = 1.26) compared with that time points in the CTRL condition. The maximal isometric half-squats effectively improved sprint performance and significantly decreased vastus lateralis tone and stiffness. These findings offer new insights into the assessment of viscoelastic properties for evaluating the fatigue or potentiation state, which requires further investigation.