Eccentric contraction duration in bodyweight resistance exercise training for changes in physical function and health parameters of older adults.

INTRODUCTION: In bodyweight resistance exercises, slow eccentric contractions are commonly performed, but it is not clear how slow they should be to maximize changes in physical function and health parameters following training. We tested the hypothesis that a longer eccentric contraction (5-s) would induce greater effects on older adults than a shorter contraction (3-s). METHODS: Forty-six healthy older adults (77.1 ± 7.0 y) performed six bodyweight resistance exercises twice weekly for 10 weeks with 3-s (n = 24) or 5-s (n = 22) eccentric contractions but minimum effort for concentric contractions in each exercise, thus the between group difference was only the eccentric contraction duration. Resting heart rate, systolic blood pressure (SBP), maximal voluntary isometric contraction strength of the knee extensors (MVC), five-times sit-to-stand (5STS), 3-m timed up and go (TUG), 6-m normal walking time (6WT), one-leg standing test with eyes open (OLST) and blood lipid parameters were assessed before and after the intervention, and compared between groups using two-way repeated-measures ANOVA. RESULTS: No significant differences were observed between groups (P = 0.159-0.914) for changes in the measures. Both groups showed significant (P < 0.05) improvements in SBP ( ~ - 5%), MVC (~ 8%), 5STS ( ~ - 7%), TUG ( ~ - 5%), total cholesterol ( ~ - 6%), and low-density lipoprotein cholesterol ( ~ - 9%). It is interesting to note that attrition was lower in the 3-s group (17%) than the 5-s group (50%). CONCLUSION: These results did not support the hypothesis and showed no significant differences between groups. The higher retention in the 3-s group may suggest greater practicality, although this may not be attributed to the contraction duration alone.