Determining The Optimal Average Velocity During High-speed Power Training In Older Adults

Abstract

Velocity based training in young, athletic populations has established the optimal velocity at which performance benefits are maximized; however, there is little data on the optimal velocity at which older adults should train to enhance performance of daily functional tasks. PURPOSE: To examine lower limb velocity during high-speed power training (HSPT) to identify whether differences in limb movement velocity may impact physical functioning in older adults. METHODS: 28 older men and women (71.5±6.8 yrs) participated in 12 weeks of lower extremity HSPT consisting of 3 sets of 14 repetitions of leg press (LP) exercises at 40% 1RM, 3 times/week. Participants performed the concentric portion of each contraction at a self-selected maximal speed (i.e., “as fast as possible”). Average velocity of each contraction of the left and right leg during training (14 repetitions x 3 sets, 3x/wk) was assessed over 12 weeks (36 training visits). Group allocation to high velocity (HI-V: n=14) and low-velocity (LO-V: n=14) was assigned based on performance of LP exercise above or below the median average velocity obtained throughout the 12-week training period. The change scores (post minus baseline) of 3 functional measures (habitual gait velocity [HGV], maximal gait velocity [MGV], and timed up and go [TUG]) were compared between HI-V and LO-V using ANOVA models covarying for age, sex, and baseline functional score a priori. Statistical significance was accepted at p<0.05. RESULTS: The median average velocity of 42 left and right LP contractions (n=3024; 3 x 14 over 36 visits) for each of the 28 participants was 0.88 m/s (HI-V: 1.0±0.08 m/s; LO-V: 0.75±0.09 m/s; p<0.001). Improvements in HGV (HI-V: 0.09±0.04 m/s vs. LO-V: -0.06±0.05 m/s; p=0.03), MGV (HI-V: 0.08±0.04 m/s vs. LO-V: -0.12±0.05 m/s; p=0.01), and TUG (HI-V: -1.15±0.30 s vs. LO-V: 0.53±0.34 s; p=0.003) were significantly greater for HI-V compared to LO-V. CONCLUSIONS: Because of the variable nature of self-selected maximal limb velocity during HSPT in older adults, identification of the optimal average velocity at which to train to improve functional performance is paramount. These data indicate that an average velocity of 0.88 m/s during LP exercise training may be necessary to ensure functional improvements in older adults participating in HSPT.