ECSS Paris 2023: OP-AP08
INTRODUCTION: The Autoregulation Rest Redistribution Training (ARRT) is a cluster-set resistance training method in which the resistance training structure is personalised according to an individual autoregulation target. Specifically, the number of clusters, repetitions per cluster and between-cluster rest intervals are dynamically adjusted to mitigate the within-session fatigue causing a decay of resistance training performance. While emerging evidence points to the superior performance effects of the ARRT method compared to traditional (TRA) resistance training methods, the underpinning neuromuscular fatigue mechanisms remain unexplored. Therefore, the aim of this study was to compare the effects of TRA and ARRT approaches on mechanical outputs and electromyographic responses during isokinetic contraction tasks. METHODS: Eighteen male subjects performed two experimental sessions in a randomized order. Both sessions consisted of 24 isokinetic single-leg extension repetitions, executed in concentric mode at a speed of 60 degrees ∙ s-1 and performed according to two training configurations; traditional (TRA): 3 sets of 8 repetitions with 120s interset rest, ARRT: a personalized combination of clusters, repetitions per cluster, and between-cluster rest regulated upon a 20% peak torque loss threshold from the first repetition. Work outputs were recorded repetition-by-repetition. Surface electromyograms (EMG) were recorded from the Vastus Medialis (VM), Rectus Femoris (RF) and Vastus Lateralis (VL) muscles, at both the proximal and distal portions. For each movement cycle, the mean frequency (MNF) of the EMG spectrum was computed according to the Choi-Williams time-frequency analysis. Then, changes in MNF across repetitions were considered to assess how prone the muscles were to fatigue: the myoelectric manifestation of muscle fatigue. The effects of TRA and ARRT on work outputs and EMG responses were investigated using linear mixed-effect and spline mixed-effects models, respectively. RESULTS: A significant interaction between protocol and repetition was found on work loss (0.41J × repetition, p<0.001) indicating that TRA induced greater work loss per repetition compared to ARRT. Overall, no significant effects of training protocol were found on changes in MNF (p=0.059). However, a main effect of muscle was found indicating greater MNF changes in the RF compared to both VM and VL (both p<0.001). Finally, similar MNF responses were observed between the proximal and distal portions of the muscles (p=0.956). CONCLUSION: The ARRT approach resulted in a similar myoelectric manifestation of fatigue as the TRA, indicating a comparable peripheral metabolic stress induced by TRA and ARRT. It is therefore possible the distinct mechanical outputs between the two training methods may have stemmed from neural and motivational factors.
Read CV Lorenzo RattalinoECSS Paris 2023: OP-AP08
INTRODUCTION: Listening to music could be an encouraging way to increase adherence and enjoyment in physical activity practice. The effects of music on physical activity have been comprehensively studied (1) and showed that music could be an ergogenic aid in improving psychological and psychophysical states, besides exercise performance (2). However, previous research focused on exercises that are hardly found in everyday sport practice (e.g. handgrip tests, and isometric strength tests) (3,4). Thus, this study aimed to investigate the effects of self-selected music (SSM) and motivational music (MM) on bench press power training. METHODS: Twenty healthy young men with at least two years of experience in resistance training participated in the study. In the first session, subjects were familiarized with the experimental settings and performed the 1-repetition maximum (1-RM) test. Then, they underwent three bench press sessions in a randomized order: with SSM, MM, and no music (NM) as a control condition. A 48-hour recovery occurred between sessions. In each session, subjects performed three sets of eight repetitions at 75% of 1-RM. We calculated the mean power (PAVG) and peak power (PPEAK) for every completed repetition. Subjects were administered the Borg scale CR-10 (RPE), the Feeling Scale (FS), and the Felt Arousal Scale (FAS) within each session. A two-way analysis of Variance (ANOVA) for repeated measures investigated the main effect of music (i.e., SSM, MM, and NM) and fatigue (i.e., first, second, and third set) or the interaction between them on the bench press power outputs (i.e., PAVG and PPEAK). Moreover, a one-way ANOVA was performed to investigate the effect of music on FAS, FS, and RPE. The level of significance was set to p<0.05. Bonferroni post hoc analysis was performed where appropriate. RESULTS: A significant main effect of music (p<0.01) and fatigue (p<0.01) was found for PAVG and PPEAK. The post hoc analysis outlined higher power values only in SSM compared to NM (p<0.05). Moreover, PAVG and PPEAK values decreased from the first to the third set (p<0.001). However, when comparing the third set, SSM highlighted higher power values than NM (p<0.01). SSM and MM positively affected FS (p=0.030) and FAS (p<0.001) scores. Interestingly, FAS scores resulted higher in SSM with respect to MM and NM (p<0.05). No changes in perceived exertion were detected. CONCLUSION: Our data highlighted improved performance during the bench press exercise when subjects listened to music. Notably, self-selected music seemed to be as effective as motivational music independently from the beats per minute (BPM). Moreover, SSM led to a higher psychophysical activation than MM. Our findings thus encourage the use of self-selected music during resistance training. REFERENCES: 1) Terry et al., Psychol. Bull., 2020 2) Karageorghis & Priest, Int. Rev. Sport Exerc. Psychol., 2012 3) Ballmann et al., J. Strength Cond. Res., 2021 4) Bartolomei et al., Percept. Mot. Skills, 2015
Read CV Matteo BozzatoECSS Paris 2023: OP-AP08
INTRODUCTION: Following a bout of high intensity exercise of short duration, the muscle is both in a fatigued or a potentiated state (1), yet studies have mainly investigated the effects of pairing heavy resistance exercises with plyometric exercise (2). This study introduces a novel approach: examining the acute effects of a postactivation performance enhancement (PAPE) protocol using isometric contractions paired with a sports-specific exercise. Given the relationship between peak power output (PPO) and diverse athletic performances (3), enhancing this physical capability holds the potential to yield more pronounced training adaptations and improved competitive outcomes. Therefore, the purpose of this study was to investigate the acute effects of a preload isometric stimulus (PIS) usings maximal voluntary isometric contractions (MVIC) on cycling PPO with a focus on the individual recovery interval for PAPE. METHODS: Twenty male (age=31.6±5.52 y; stature=185.9±6.7 cm; body mass=94.3±9.2 kg) professional athletes performed a 6 second PPO cycling test (PPT6) after a preload stimulus (3 MVICs), at the following timepoints: baseline, 15 seconds, and 4, 8, 12 and 16 minutes. Cycling PPO was measured as an indicator of performance at each time point. RESULTS: A repeated measures ANOVA on cycling parameters revealed a statistically significant time effect for PPO (F=5.737, p=0.0001). Post hoc analyses indicated no significant changes in PPO at the 15-second post-preload stimulus (p=0.337), with a non-significant increment at the 4-minute recovery time slot (p=0.297). A significant PPO increase occurred after 8 and 12 minutes of recovery when compared to baseline (both p=0.007). Correlation analyses identified associations between impulse (IMP1-3), skinfold (Sum5), bodyweight (BW), and PPO. Significant correlations were established between PPO and magnitudes of fatigue during the PIS in both peak force (PF1-3) and impulse (IMP1-3). Particularly noteworthy were the negative correlations between the slope of PF1-3 fatigue and the 15-second, 8-minute, and 16-minute time points. CONCLUSION: The study demonstrates that sprint cycling performance experiences potentiation after rest periods of 8 and 12 minutes following a PIS. Additionally, the results also highlight the need for a PIS to limit recovery between bouts of exertion for optimal efficiency. Finally, these findings suggest the practical applicability for integrating PIS as a PAPE strategy, particularly within the framework of contrast training or within a competitive context involving sprint cycling. 1. Tillin et al., (2009). Sports medicine. 39. 147-66 ; 2. Docherty et al., (2008). International journal of sports physiology and performance. 2. 439-44. 3. Kilduff et al., (2007). Journal of strength and conditioning research 21. 1134-8.
Read CV Kilian PhilippeECSS Paris 2023: OP-AP08