This study aimed to narrow down the possible mechanisms of Post-Activation Performance Enhancement (PAPE), especially if they are exclusively found in the muscle. It was therefore investigated whether (1) the PAPE effect is influenced by neural factors and (2) if Post-Activation-Potentiation (PAP) influences PAPE. Thirteen strength-trained participants (26.5 ± 3.2 years) took part in at least one of three interventions (PAP, PAPE-Electrical (PAPEE), and PAPE-Voluntary (PAPEV)). Conditioning contractions (CC) and testing involved isometric knee extensions performed on an isokinetic device at an 80° knee flexion angle. The CC was either performed voluntarily (PAP, PAPEV) or was evoked through electrical stimulation (PAPEE). Testing was performed at baseline and after two seconds, four minutes, eight minutes, and twelve minutes of the CC. Maximum voluntary isometric contractions (MVIC) for the PAPE trials and supramaximal twitches for the PAP trial were used for testing. Parameters of interest were peak torque and rate of torque development (RTD), and electromyography (EMG) amplitude of the quadriceps (only PAPE). Repeated measures ANOVA and simple contrast comparisons were used for statistical analysis. Peak torque (p < 0.001, η2p = 0.715) and RTD (p = 0. 005, η2p = 0.570) increased significantly during the PAP protocol immediately two seconds after the CC and decreased to near baseline values for the following time points (p > 0.05). Peak torque, RTD, and peak EMG showed no significant differences during PAPEE and PAPEV trials (p > 0.05). Due to the lack of a visible PAPE effect, the question of whether neural mechanisms influence PAPE cannot be answered. Due to the time course of the PAP analysis, it is questionable if these mechanisms play a role in PAPE. The assumption that the PAP mechanism influences PAPE cannot be confirmed for the same reason.

Background and Objectives: The Nordic hamstring exercise (NHE) effectively strengthens the hamstrings, reduces the risk of hamstring strain, and induces fatigue in the muscles; thus, post-NHE recovery strategies should be optimized. Foam rolling (FR) is a widely used method, with the belief that it can speed up recovery. Thus, this study investigated the acute and 48-h effects of FR following the NHE on muscle stiffness, pain pressure threshold (PPT), flexibility, countermovement jump (CmJ) height, and maximal voluntary isometric contraction (MVIC). Materials and Methods: Thirty-two active males were randomly assigned to either an FR group (n = 16) or a passive recovery (PR, n = 16) group. Measurements were taken at three time points: pre-test, post-test_0h, and post-test_48h. Participants performed the NHE (3 sets × 10 reps) before the recovery interventions. Variables assessed included muscle stiffness (MyotonPro), flexibility (sit and reach), PPT (algometer), jump performance (force platform), and MVIC peak torque (dynamometer). Results: FR significantly improved acute flexibility (12.7%, p < 0.001) following the NHE and prevented flexibility loss at 48 h, compared to the PR group. However, FR showed no significant advantages over PR in terms of muscle stiffness, PPT, CmJ, or MVIC, both acutely and at 48 h (p > 0.05). Conclusions: FR is an effective acute recovery strategy for improving flexibility after the NHE but offers limited effects for muscle stiffness, PPT, and other functional muscle parameters, both acutely and at 48 h. Further research should explore the long-term effects and efficacy of FR across diverse populations and recovery scenarios.

This study examined muscle excitation using surface electromyography (sEMG) during different ranges of motion (ROM) in the bench press. Given the limited research on upper-body muscle excitation across ROMs, this study aimed to establish reference values for muscle excitation in distinct bench press ROMs. Nineteen male participants performed a 10-repetition maximum (10RM) bench press across three ROMs: full ROM, upper-half ROM, and lower-half ROM. sEMG measurements were taken on the pectoralis major (PM), triceps brachii (TB), and anterior deltoid (AD). Mean and peak EMG amplitudes were analyzed. Significant differences in mean muscle excitation were observed across all muscles (p < 0.001–0.002). The upper-half ROM elicited the highest mean excitation for the TB, while both partial ROMs resulted in greater excitation for the PM and AD compared to the full ROM. Peak muscle excitation was significantly greater in the PM sternocostal 15% region during the upper-half ROM. Additionally, the TB long and lateral heads showed significantly higher peak EMG values in the upper-half ROM than in the other conditions. These results suggest that ROM variations in the bench press lead to distinct muscle excitation patterns. This insight may inform future research on ROM’s effects on muscle hypertrophy and strength development.

This study investigated muscle excitation via surface electromyography (sEMG) during different ranges of motion (ROMs) in the prone barbell row. Sixteen resistance-trained males performed a 10-repetition maximum (10RM) across three ROMs: full, upper half, and lower half. Time under tension was standardized at 2 s for both the concentric and eccentric phases. SEMG measurements were taken for the trapezius transversus (TT), rear deltoid (RD), latissimus dorsi (LD) and biceps brachii (BB). Mean sEMG amplitude and peak sEMG amplitude were analyzed. The LD showed significantly higher mean muscle excitation in the upper-half ROM compared to both the lower-half ROM (p < 0.001, d = - 0.59) and full ROM (p < 0.001, d = - 0.58). The TT exhibited significantly lower peak excitation in the upper-half ROM compared to the lower-half ROM (p = 0.042, d = 0.42) and full ROM (p = 0.013, d = 0.54). For the other muscles, no significant difference between the ROMs was found. The effect of ROM during the prone barbell row exercise on muscle excitation was of a medium magnitude only, as well as inconsistent, suggesting that ROM adjustments with standardized time under tension have limited impact on overall muscle activation.

Purpose: Vibrational stimulation was suggested sufficient to acutely enhance range of motion (ROM). However, the actual merit of superimposed vibration and underlying mechanical or sensory mechanisms of ROM increases due to local vibration are not well understood. Methods: Using a randomized controlled cross-over trial, this study opposed two minutes of stretching + vibration (STV) to vibration (V) and stretching (ST) alone as well as a passive control (CG) in 30 healthy, recreationally active participants. Pre- and post-intervention measurements of ankle dorsiflexion ROM, ankle passive torque, and gastrocnemius medialis muscle stiffness were conducted using a dynamometer and shear wave elastography, respectively. Results: All interventions significantly increased ROM (p < 0.001, η ² = 0.622) compared to CG, with no additional benefits observed for vibration combined with stretching compared to stretching or vibration alone. However, combining stretching and vibration produced the most pronounced reductions in passive torque over the whole ankle ROM. The combination demonstrated additive effects of stretching and vibration, which affected passive torque in the end ROM and at rest, respectively. Muscle stiffness decreased, but did not differentiate between conditions. Conclusion: These findings negate additional acute vibration effects on ROM that surpass the effects of stretching alone, while the combination of stretching and vibration presented the most prominent influence on passive torque and joint resistance. Vibration also increases stretching pain tolerance; this might facilitate the conduction of exercises and improves compliance as well as adherence to stretching habits.