Effects of Weight Loss on Lean Mass, Strength, Bone, and Aerobic Capacity

PURPOSETo evaluate the hypothesis that exercise attenuates the reductions in lean mass, muscle strength, BMD, and VO2max that accompany modest weight loss induced by calorie restriction. METHODSOverweight, sedentary women and men (n=52, 45–65y) were randomized to 6-8% weight loss by using calorie restriction (CR), endurance exercise (EX), or both (CREX). The CR and CREX groups underwent counseling to reduce energy intake by 20% and 10%, respectively. The EX and CREX groups exercised 7.4±0.5 and 4.4±0.5 hr/wk, respectively. Before and after 16.8±1.1 weeks of weight loss, lean mass and BMD were measured with dual-energy X-ray absorptiometry, strength was measured with dynamometry, and aerobic capacity (VO2max) was measured with indirect calorimetry during maximal-intensity treadmill exercise. RESULTSWeight loss was ~7% in all groups. Decreases in whole body (~2%, p=0.003) and lower extremity (~4%, p