Moderate-intensity Aerobic and Resistance Training Increases Lean Tissue Mass and Strength In HIV-infected Men

Abstract

People living with HIV experience a decline in muscular strength and reduced muscle mass that may be related to the viral infection, or due to the sedentary lifestyle that is common among this understudied population. PURPOSE: The purpose of this study was to examine the level of strength gain and lean tissue mass gain in HIV-infected men who participated in a regimen of moderate intensity exercise. METHODS: Subjects were randomly assigned to either an exercise (EX) or control (CON) group. The intervention consisted of 6 weeks of moderate-intensity exercise that included 30 minutes of aerobic (60% MHR) and 20 minutes of resistance training (60% 3RM) performed twice weekly. Neither group had an increase in activity outside of the study. Data was collected by administering a 3-repetition maximal test for leg extension (Le), leg curl (Lc), latissimus pull-down (Lpd), and chest press (Cp). These tests were administered twice prior to and twice after the exercise program on non consecutive days. The higher of each pair of tests was included for calculating group means. Data collected from EX and CON subjects were analyzed, within and between groups, using ANOVA. RESULTS: Pre-exercise baseline levels for all resistance movements were similar between groups. Significant increases in LTM were seen were seen in the EX group(56.3±1.1 to 57.1±1.1 kg), but not the CON group (55.9±1.15 to 55.9±1.6 kg). Significant strength gains were seen in the EX group, but not the CON group, for the Lpd (16.5±3.8 lbs) and Cp (16.8±2.1 lbs). However, strength gains were seen in both groups for Le (EX=26.3±4.3 lbs; C=21.4±8.4 lbs) and Lc (EX=22.8±5.8 lbs; C=17±3.7 lbs). CONCLUSIONS: The data indicate that the EX group's LTM increased, while the CON group resulted in no changes. The data indicate that strength gains occurred in the EX group for both the upper and lower body, while the CON group experienced strength gains in the lower body only. These results suggest that manageable exercise training levels in the moderate intensity range can elicit increases in LTM, upper body, and perhaps lower body, strength gains in HIV-infected individuals. Funded by the NIH/NCMHD (5P20MD001770) and ACSM.