A randomized trial of weighted vest use in ambulatory older adults: Strength, performance, and quality of life outcomes

BACKGROUND: Lower extremity weakness is a major risk factor for falls and h ip fractures. Aging muscle is capable of responding to strengthening techni ques, Strategies for providing accessible, inexpensive, safe, and effective strengthening programs for older adults are needed. OBJECTIVE: To evaluate whether use of a weighted vest improved strength, physical performance, ma rkers of bone turnover, or health-related quality of life. DESIGN: A 27-week randomized, controlled, unmasked clinical trial. The prim ary outcome was peak isokinetic knee extensor strength at follow-up, adjust ed for baseline strength. SETTING: Home-based program. PARTICIPANTS: A total of 62 women and men, mean age 74 years. INTERVENTIONS: Subjects were randomized to: no vest (n = 21), 3% body weigh t (BW) vest (n = 19), or 5% BW vest (n = 22). The vest is a nylon garment w ith pockets that are loaded with adjustable weights. The vest was prescribe d for 2 hours daily, 4 days per week. No specific physical activities were mandated. MEASUREMENTS: All measures were made at baseline and 27 weeks. These includ ed: knee strength and endurance by isokinetic dynamometer; timed physical p erformance tests; serum osteocalcin and urinary N-telopeptides; and health- related quality of life scales. RESULTS: Follow-up values of muscular strength and endurance, physical perf ormance, bone turnover markers, and health-related quality of life did not differ by treatment assignment. The final study visit was attended by 19 (9 0%), 15 (80%), and 20 (91%) of the control, 3%, and 5% groups, respectively . Three permanent discontinuations of vest use occurred. CONCLUSIONS: Weighted vest use did not result in improvement in multiple do mains of strength and function and did not affect bone turnover markers. We conclude that the training stimulus afforded by the vest (at the dosage te sted) was below the required amount to produce strength gains or bone stimu lation.