ABSTRACT
HIV/AIDS and its treatment often alter body composition and result in poorer physical functioning. The aim of this study was to determine the effects of a moderate-intensity exercise program on body composition and the hormones and cytokines associated with adverse health outcomes. HIV-infected males (N = 111) were randomized to an exercise group (EX) who completed 6 weeks of moderate-intensity exercise training, or to a nonintervention control group (CON). In pre- and postintervention, body composition was estimated via DXA, peak strength was assessed, and resting blood samples were obtained. There was a decrease in salivary cortisol at wake (P = 0.025) in the EX and a trend (P = 0.07) for a decrease 1 hour after waking. The EX had a significant increase in lean tissue mass (LTM) (P < 0.001) following the intervention. Those in the EX below median body fat (20%) increased LTM (P = 0.014) only, while those above 20% decreased fat mass (P = 0.02), total fat (N = 0.009), and trunk fat (P = 0.001), while also increasing LTM (P = 0.027). Peak strength increased between 14% and 28% on all exercises in the EX group. These data indicate that 6 weeks of moderate-intensity exercise training can decrease salivary cortisol levels, improve physical performance, and improve body composition in HIV-infected men.
ABSTRACT
Exercise has the potential to impact disease by altering circulating anabolic and catabolic factors. It was the goal of this study to determine how different regimens of low-intensity and moderate-intensity exercise affected circulating levels of these anabolic and catabolic factors in HIV-infected men. Exercise-naive, HIV-infected men, medically cleared for study participation, were randomized into one of the following groups: a moderate-intensity group (MOD, who completed 30 min of moderate-intensity aerobic training followed by 30 min of moderate-intensity resistance training; a low-intensity group (LOW), who completed 60 min of treadmill walking; or a control group (CON), who attended the clinic but participated in no activity. Blood and saliva samples were collected at selected time points before, during, and after each of the 3 required sessions. Compared with baseline, the MOD group (n=14) had a 135% increase in growth hormone (GH) (p<0.05) and a 34% decrease in cortisol (CORT) (p<0.05) at the post time point, a 31% increase in interleukin-6 (IL-6) (p<0.05) at 30-min post exercise, and a 23% increase in IL-6 (p<0.05) and a 13% decrease in soluble tumor necrosis factor receptor 2 (sTNFrII) (p<0.05) at 60-min post exercise. The LOW (n=11) group had a 3.5% decrease in sTNFrII (<0.05) at 30-min post exercise compared with baseline and a 49% decrease (p<0.05) in GH at 60-min post exercise. The CON group (n=13) had a decrease in GH at 30-min (62%, p<0.05) and 60-min (61%, p<0.05) post exercise compared with baseline. The increase in GH from baseline to post was greater in the MOD group (p<0.05) and the decrease in CORT from pre to post was greater in the MOD group (p<0.05) than in the other groups. These data suggest that individual sessions of both low-intensity and moderate-intensity exercise can alter circulating anabolic and catabolic factors in HIV-infected men. The changes in the MOD group present potential mechanisms for the increases in lean tissue mass seen with resistance exercise training.
