Background: Lower extremity weakness is a major risk factor for falls and hip fractures. Aging muscle is capable of responding to strengthening techniques. 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, markers of bone turnover, or health-related quality of life.
Design: A 27-week randomized, controlled, unmasked clinical trial. The primary outcome was peak isokinetic knee extensor strength at follow-up, adjusted 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 weight (BW) vest (n = 19), or 5% BW vest (n = 22). The vest is a nylon garment with pockets that are loaded with adjustable weights. The vest was prescribed 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 included: knee strength and endurance by isokinetic dynamometer; timed physical performance tests; serum osteocalcin and urinary N-telopeptides; and health-related quality of life scales.
Results: Follow-up values of muscular strength and endurance, physical performance, bone turnover markers, and health-related quality of life did not differ by treatment assignment. The final study visit was attended by 19 (90%), 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 domains of strength and function and did not affect bone turnover markers. We conclude that the training stimulus afforded by the vest (at the dosage tested) was below the required amount to produce strength gains or bone stimulation.