ECSS Paris 2023: CP-AP17
INTRODUCTION: Acute resistance training performance is influenced by daily internal load fluctuations. Training individualisation and auto-regulation adjust external load according to internal load variations to optimise performance and manage fatigue, though evidence of their superiority over linear progression for strength and hypertrophy is inconsistent. Furthermore, limited research has examined which internal load markers are most strongly associated with acute external load performance. Therefore, this study examined the relationship between daily internal load variations and external load during resistance training. METHODS: Eight resistance-trained healthy participants (4 F; age 36.4 ± 11.7 y; training experience 15.3 ± 10.1 y) completed a 4-week single-group protocol including 1RM testing, six resistance training sessions, and 1RM re-testing with ≥ 48 h between sessions. Training was performed twice per week for three weeks at 80% 1RM for the leg extension, leg curl, chest press, arm extension, low row and arm curl, with three sets to muscular failure per exercise and 2-min rest intervals. Exercises were paired and their order was counterbalanced across sessions. Before each session, psychophysiological status was assessed via questionnaires (EES, FFS–Fatigue, SQS, PRS, VAS-DOMS) and neuromuscular measures (BIA, handgrip strength, Ruffier test, isokinetic tests). Post-session assessments included physical and mental session RPE, FFS–Fatiguability, EES, and repeated neuromuscular measures. RESULTS: Two separate linear regression models were conducted. In the first model, the fatiguability sub-scale was included as the dependent variable, while psycho-physiological measures and load-related indices were independent variables. Session physical RPE was positively associated with fatiguability. Conversely, physical sRPE-to-tonnage ratio was negatively associated with fatiguability. In the second model, session mental and physical RPE were included as independent variables, psycho-motivational variables and external load were included as dependent variables. Tonnage was positively associated with both session mental and physical RPE. Additionally, sleep quality was negatively associated with session mental RPE. No further significant relationships were detected in both analysis. CONCLUSION: The present findings indicate a consistent association between external load and internal load markers during resistance training. Greater training volume was accompanied by higher perceived mental and physical fatigue, supporting the relationship between mechanical demand and subjective load. Physical RPE was associated with post-session fatiguability, suggesting that perceived exertion reflects acute fatigue. The association between poor sleep quality and higher mental fatigue highlights the contribution of non-training-related internal load factors to perceived session demands. Results should be interpreted cautiously due to the small sample size, short intervention and preclude causal inference.
Read CV Alessandro BracciECSS Paris 2023: CP-AP17