ECSS Paris 2023: OP-AP36
INTRODUCTION: Responsiveness to post-activation performance enhancement is mediated by moderators such as training experience, conditioning activity (CA) volume and intensity, and post-CA recovery interval. In a recent metanalysis, Xu et al. [1] provided an evidence-based framework for designing effective PAPE protocols for both clinical and research purposes. Their finding indicated that, regardless of CA type, the optimal post-CA recovery interval (OPT) ranges between 2.5 and 11 minutes, peaking at 5.5 minutes. Given the high inter-individual variability in PAPE responsiveness and the relatively wide range of OPT observed by Xu et al. [1], our aim was to analyze the distribution of the OPT in a large sample. We hypothesized that OPT would not follow a normal distribution. METHODS: Following familiarization and 1-RM determination sessions, forty-six trained males (23.8±4.0 years, 79.0±12.8 kg, 175±3 cm) who were PAPE responders attended the laboratory on two separate days to complete an experimental and a control session in randomized order. The control session involved assessing countermovement jump (CMJ) performance at baseline, followed by a standardized warm-up comprising five minutes of light cycling and three sets of three unloaded squats. CMJ performance was subsequently assessed at 2, 4, 6, 8, and 10 minutes post-warm-up. In the experimental session, instead of the standardized warm-up, participants performed a CA consisting of three sets of three barbell squats at 87% 1-RM. CMJ performance was assessed at the same time points as in the control session. The recovery interval at which each participant achieved their best CMJ performance was recorded as their OPT. A two-way ANOVA was conducted to compare CMJ performance between sessions and across recovery intervals. OPT distribution was tested using the Smirnov-Kolmogorov test. RESULTS: CMJ performance declined two minutes after seated rest (34.7±6.2 vs 33.6±6.6 cm) but returned to baseline levels for the remainder of the control session, indicating that the assessment protocol did not induce significant potentiation. In the experimental session, CMJ performance was significantly higher than baseline (33.3±7.0 cm) at all time points post-CA (2 min: 35.6±6.9 cm; 4 min: 36.1±7.0 cm; 6 min: 35.9±6.7 cm; 8 min: 35.5±6.5 cm; 10 min: 35.1±6.3 cm). The mean, median and mode OPT were 4.8, 4.0, and 4.0, respectively. OPT distribution was non-gaussian (D[46] = 0.236, p < 0.01,). CONCLUSION: Our findings support the data reported by Xu et al. [1] demonstrating that the mean OPT is approximately 5.5 minutes post-CA. Our hypothesis that OPT distribution would not be normal was confirmed by the obtained data, suggesting that individualized post-CA recovery intervals should be adopted when designing protocols aimed at inducing PAPE. [1] Xu, K. et al. (2025). Optimizing post-activation performance enhancement in athletic tasks: a systematic review with meta-analysis for prescription variables and research methods. Sports Med, Online ahead of print.
Read CV Leonardo LimaECSS Paris 2023: OP-AP36
INTRODUCTION: Sleep is essential for optimal physical and cognitive performance, yet its effects on resistance exercise performance remain unclear in women. This study aimed to investigate the effects of acute sleep restriction on maximal strength, muscle power, and strength endurance in resistance-trained women. METHODS: Eight resistance-trained women (age:25±4 years; BMI:23.0±2.8 kg/m2 ) participated in a randomized, counterbalanced, crossover study, completing two identical experimental sessions under different sleep conditions: a) night of habitual sleep (HS) and b) acute sleep restriction (SR) at the beginning of the night (i.e. 3 hours less than habitual sleep with a delayed bedtime). Sleep was monitored using wristwatch actigraphy (MotionWatch8, CamNtech, Neurotechnology Ltd., Cambridge, UK) to ensure compliance. Each session took place at the same time (~09:00am) and included: a) one repetition maximum test (1RM) in bench press exercise; b) three sets of three repetitions of explosive bench press exercise at 50%1RM; c) countermovement jump (CMJ) and d) strength endurance test in the bench press exercise at 50% 1RM. Before testing, participants completed: a) the Readiness-to-Train Questionnaire (RTT-Q) and b) the Self-Assessment Manikin questionnaire (SAM) to assess arousal and valence. Immediately after testing, ratings of perceived exertion (RPE; 6-20) and pain levels on visual analogue scale (VAS; 0-10) were obtained. Difference between conditions was determined by paired T-tests or Wilcoxons tests according to data distribution, except explosive bench press exercise, where a two-way ANOVA was applied. Effect sizes (ES) were calculated using Hedge’s. RESULTS: No significant differences between HS and SR conditions were observed in: a) 1RM (45.9±5.1 kg vs 44.4±5.6 kg; p=0.14; ES=0.26; Δ=-3.3%); b) peak (1.52±0.15 m/s vs. 1.42±0.23 m/s; p=0.13; ES=0.49; Δ=-6.6%), and mean (1.12±0.11 m/s vs. 1.00±0.15 m/s; p=0.05; ES=0.86; Δ=-10.7%) bar velocity during explosive bench press exercise; c) CMJ (28.6±4.8 cm vs 29.0±6.3 cm; p=0.22; ES=-0.07; Δ=1.4%) and d) number of repetitions during strength endurance test (37±9 vs 34±6; p=0.22; ES=0.37; Δ=-8.1%). Significant differences between HS and SR conditions were noted on SAM scores for arousal (62±19 arbitrary unit a.u.) vs 36±12 a.u. ; p=0.01; ES=1.55), dominance (71±21 a.u. vs 43±19 a.u.; p=0.02; ES=1.32) and valence (77±22 a.u. vs 45±27 a.u. ; p=0.01; ES=1.23), without changes in RTT-Q, RPE and VAS. CONCLUSION: Acute sleep restriction (3-hour reduction) does not significantly impair maximal strength, muscle power, or strength endurance in resistance-trained women. However, reduced emotional state scores indicate a negative impact on mood and psychological readiness. While short-term sleep loss may not immediately affect physical performance, it could influence motivation and long-term outcomes. Further research is needed to explore the relationship between emotional state and resistance training performance after sleep restriction.
Read CV Zuzanna KomarekECSS Paris 2023: OP-AP36
INTRODUCTION: Stretching can acutely increase the maximum range of motion (ROMmax). However, its effects on muscle mechanical properties vary depending on the type, intensity, and duration of the stretching maneuver. Shear-wave elastography (SWE) was used to assess muscle stiffness by measuring ultrasound wave speed through the tissue. This speed can be converted into modulus (μ, kPa), providing an estimate of tissue elasticity. Recently, SWE has been applied to investigate stretch-induced changes in muscle stiffness. Since different muscle regions may exhibit different μ values, we examined whether three stretching protocols affected μ differently in two muscle regions. METHODS: Twelve participants (8 men, 4 women; mean±SD: age = 23.9±2.4 years, body mass = 69.8±10.6 kg, height = 172.0±8.5 cm) completed three stretching sessions on separate days. ROMmax was assessed. GM stiffness (μ) was measured using SWE (V8, Samsung Healthcare, Seoul, Korea) at both a neutral ankle angle (90°) and at 80%ROMmax in the middle muscle portion (GMmid) and the muscular region of the GM myotendinous junction (MTJ). Measurements were taken PRE and immediately POST 5×30-s passive static stretching (PS30, 30-s inter-set rest), 5×45-s PS (PS45, 15-s inter-set rest), and 5×30-rep dynamic stretching (DS, 30-s inter-set rest). The order was randomized. The same absolute angle at 80%ROMmax was used in POST evaluations. Within-day reliability was assessed before stretching using intraclass correlation coefficient (ICC) analysis. Data were analysed with repeated-measures ANOVA (within-factors: stretching type, region, ankle angle, time) at p<0.05, with Bonferroni correction for pairwise comparisons. RESULTS: ICCs were >0.80 for all parameters. No significant differences were found at PRE across the three days (p>0.05). No main interactions were observed (p>0.05). PS30 increased ROMmax (8.4%, p<0.01) and decreased GMmid μ at 80%ROMmax (−17.6%, p<0.01). PS45 increased ROMmax (7.8%, p<0.01) and decreased GMmid μ at 80%ROMmax (−14.2%, p<0.01), as well as MTJ μ at both 90° (−13.4%, p<0.01) and 80%ROMmax (−8.6%, p<0.01). DS increased ROMmax (11.1%, p<0.01) and reduced GMmid μ at 80%ROMmax (−12.5%, p<0.01) and MTJ μ at 90° (−12.7%, p<0.01), while the decrease at 80%ROMmax was not significant (−8.3%, p>0.05). CONCLUSION: This study highlights that stretching-induced changes in muscle stiffness can be region-specific and depend on the protocol used. Longer-duration static stretching was more effective in reducing stiffness across GM regions. Dynamic stretching improved ROMmax but had a more limited impact on muscle stiffness, particularly at the MTJ. However, the small sample size and variability in μ may have influenced these findings. Hirata K et al. (2016). DOI: 10.1007/s00421-016-3349-3. Hirata K et al. (2019). DOI: 10.1249/MSS.0000000000002186. Maeda N et al. (2017). PMID: 29238251.
Read CV Stefano LongoECSS Paris 2023: OP-AP36