Whether older, sedentary HIV+ adults can achieve similar functional benefits with exercise as their HIV- peers and the ideal intensity of exercise needed for these benefits is not known.
Older (50-75 years of age) sedentary HIV+ (undetectable HIV-1 RNA on antiretroviral therapy for ≥ 2 years) and HIV- participants were recruited for a 24 wk supervised, 3x/week cardiovascular and resistance exercise program. Participants exercised at moderate intensity for 0-12 wks, then were randomized to moderate (50% V02 maximum [V02max], 60-70% 1-repetition maximum [RM]) or high intensity (70% V02max, ≥80% 1-RM) exercise for an additional 12 wks. 10x chair rise time and 1-RM were measured every 3 wks; V02max and 400-m walk time at wk 0, 12, and 24. Outcomes by serostatus and exercise intensity were compared using linear and mixed effects regression models and adjusted for baseline values (for wk 0-12) or wk 12 (for 12-24 wk change).
28 HIV+ and 31 HIV- participants completed 12 wks; 27 HIV+ (12 moderate/15 high) and 30 HIV- (14 moderate/16 high) completed 24 wks of exercise. HIV+ participants were thinner (BMI 27 vs 30 kg/m2), younger (57 vs 60 years), less likely never smokers (39 vs 58%), and had more comorbidities (79 vs 55% with ≥3) compared to HIV-. Among HIV+ participants the CD4+ T-cell was 564 (467,682) cells/mm3, and mean time since HIV diagnosis was 20 (17,23) yrs. At week 0, HIV+ participants had faster 400-m walk time but slower 10x chair rise (Table) compared to HIV- participants. Both groups had significant improvements in all physical function measures except V02max from 12-24 wks in HIV+ for moderate intensity (Table). HIV+ participants had significantly greater improvements than HIV- on V02 max between wk 0-12 (5 [0,10]% greater; p=0.04) and in 400-m walk between weeks 12-24 (-3 [-5,0]% faster; p=0.03). An interaction between exercise intensity and HIV serostatus was significant only on 1-RM measures: HIV+/high-intensity exercisers gained significantly more strength than HIV+/moderate exercises in bench press (6 [0, 12]% greater) and leg press (10 [2, 17]% greater; both p<0.05); HIV- had similar gains regardless of intensity.
Exercise training reverses physical function impairment to a similar extent in older, sedentary HIV+ and HIV- adults. HIV+ persons randomized to high intensity exercise showed greater gains in strength than HIV- persons, which may suggest an added benefit of high intensity exercise among older sedentary HIV+ adults.