Feasibility and Effects on Muscle Function of an Exercise Program for Older Adults.

INTRODUCTION Study objective was to determine feasibility and compliance with a 3-month exercise intervention in older adults, and if peripheral quantitative computed tomography muscle measures and jumping mechanography could detect changes in muscle mass and function. METHODS A parallel group, nonblinded, pilot trial with individuals 70 yr or older randomized to control group of walking-only (WALK) or an intervention group of walking combined with exercises to improve balance and strength (W + EX). Both groups attended similar weekly nutrition education sessions. Body composition, muscle density, intramuscular adipose tissue area, and muscle function were assessed before and after the intervention using dual-energy x-ray, peripheral quantitative computed tomography, functional tests, and mechanography. RESULTS Eighty-five (90%) of 94 individuals enrolled completed (41WALK, 44W + EX). Eighty-six percent of participants attended seven or more nutrition sessions, and log sheets, used to assess exercise compliance, were returned by 66% of participants, and of those, 88% logged activity on 50%+ days. Sixty-seven percent of participants stated that they increased activity levels, and 82% stated that they felt better overall. Both groups increased lean and lost fat mass, resulting in decreases in fat percentage (all, P < 0.05). Intramuscular adipose tissue area decreased and muscle density increased among WALK (P < 0.05 and P = 0.056, respectively) but were not different between groups. Improvement in force efficiency and chair-rise power were greater among W + EX group than WALK (5.9% ± 1.8% vs -1.2% ± 2.0% [P = 0.01] and 0.25 ± 0.19 W·kg and -0.37 ± 0.23 W·kg [P = 0.04], respectively). Differences in mechanography results became greater in a per-protocol analysis. CONCLUSIONS A larger trial is feasible, and the program was well accepted. Both groups showed improvements, the program that included strength and balance lead to greater jump force efficiency and power than walking only. Whether these differences lead to differences in fall rates need to be determined in a larger trial.