Physical function improvements with moderate or high-intensity exercise among older adults with or without HIV infection

Objective: Whether older people living with HIV (PLWH) can achieve similar functional benefits with exercise as their uninfected peers and the ideal intensity of exercise needed for these benefits are not known. Design: Sedentary adults (50 75 years) with or without HIV were recruited for 24 weeks of supervised endurance/resistance exercise. After 12 weeks of moderateintensity exercise, participants were randomized to continue moderate-intensity or advance to high-intensity exercise for an additional 12 weeks. Methods: Outcomes by serostatus and exercise intensity (moderate, high) were compared using linear and mixed effects regression models and controlled for baseline values or week 12 values. Results: A total of 32 PLWH and 37 controls were enrolled; 27 PLWH (12 moderate/15 high) and 29 controls (15 moderate/14 high) completed 24 weeks. PLWH had significantly poorer physical function across nearly all baseline measures. Both groups had significant improvements in all functional measures. From 0 to 12 weeks, PLWH had significantly greater percentage improvements (mean, 95% confidence interval) than controls on VO2 max [5 (0, 10)%]; from 13 to 24 weeks, PLWH had significantly greater percentage improvements on stair climb [5 (10, 1)%], and the time to complete a 400-m walk [3 (5, 0)%]; all P less than 0.05. An interaction between exercise intensity and HIV serostatus was significant for measures of strength: PLWH randomized to high-intensity gained significantly more strength than moderate-intensity in bench and leg press [6 (0, 12)% and 10 (2, 17)% greater; both P 0.05]; controls had similar gains regardless of intensity. Conclusion: Both moderate-intensity and high-intensity exercise resulted in significant improvements in physical function; high-intensity exercise may impart greater strength benefits to PLWH.