Validity of the individualized load-velocity profile to predict one-repetition maximum on a pneumatic leg press device in adults aged 55–81 years

INTRODUCTION: Resistance exercise is the primary strategy to counteract age-related declines in muscle function. Training loads are typically prescribed relative to an individual's one-repetition maximum (1-RM), but direct 1-RM testing is time-consuming and may increase injury risk in older adults. Because movement velocity can predict relative load, this cross-sectional study examined the accuracy of 1-RM estimation from individual load-velocity (L-v) profiles. METHODS: values were input into the individual L-v equations. RESULTS: more closely matched measured 1-RM (mean difference = -0.4 ± 6.8 kg; d = 0.06) and demonstrated statistical equivalence, with the 90% confidence interval contained within predefined equivalence bounds (±7.2 kg). CONCLUSION: showed minimal average bias, interindividual variability persisted across both estimation methods, limiting the accuracy of 1-RM predictions at the individual level.