We examined the effects of an 8-week exercise intervention on aerobic fitness, android and gynoid fat mass, and blood lipids in overweight and obese participants. Twenty-four sedentary participants (average BMI = 30 +/- 2 kg/m(2); 18 females, 6 males) were randomized into either interval training and diet education (INT group), continuous aerobic exercise and diet education (CON group), or diet education only (DIET group). Durations of exercise sessions were similar ( approximately 30 minutes), with both exercise groups completing the same amount of work. The INT and CON groups demonstrated significant improvements over time for VO(2 peak) (p < 0.01 and p < 0.05, ES = 1.1 and 1.2, respectively) and time to exhaustion on a graded exercise test (p < 0.01 and ES = 0.8 for both groups). Further, a large effect size (0.7) was recorded for the loss in android fat mass over time in the INT group only.