We calculated that a sample size of 216 persons (54 per group) was needed to have 80% power to detect a moderate 0.65-SD difference for each of 4 comparisons tested simultaneously, with an overall α value of 0.05: aerobic training versus control, resistance training versus control, combined exercise training versus aerobic training (incremental effect of resistance training beyond that of aerobic training), and combined exercise training versus resistance training (incremental effect of aerobic training beyond that of resistance training). We exceeded this sample size to allow for withdrawals. Previous studies of the effect of aerobic training alone (1) and resistance training alone (16 –18) suggested that results of each type of exercise would be comparable. Therefore, the study was not powered to compare aerobic training with resistance training, which would have required a much larger sample.