Purpose: Children with high levels of total body fat mass (TFM) and visceral adipose tissue (VAT) have elevated levels of certain risk factors for coronary artery disease and non-insulin-dependent diabetes mellitus. We tested the hypothesis that controlled physical training, without dietary intervention, would have a favorable impact on VAT and percent body fat (%BF) in obese children. Methods: A volunteer sample of 74 obese children, 7-11 yr of age, accepted random assignment to physical training or control groups. Before and after 4 months of intervention, measurements were obtained for VAT, TFM, %BF, daily physical activity, and cardiovascular fitness. The intervention involved 4 months of controlled physical training 5 d.wk(-1), 40 min per session, at a mean heart rate (HR) of 157 beats.min(-1). The estimated energy expenditure (EE) per training session was 925 +/- 201 kJ. Results: Compared with the control group, the physical training group declined significantly in %BF (Delta = -2.2%) (P < 0.01), TFM (Delta = -3.1%) (P < 0.01), and subcutaneous abdominal adipose tissue (Delta = -16.1%) (P < 0.05), and increased significantly in fat-free mass (Delta = +6.1%) (P < 0.05) and moderate-to-very hard physical activity (Delta = +14.1%) (P < 0.05). The increase in VAT was significantly less in the physical training group (Delta = +0.5%) as compared with that in the control group (Delta = +8.1%) (P < 0.05). Conclusions: This study showed that during physical training obese children: 1) were capable of participating in a substantial amount of high intensity physical training over a 4-month period; 2) accumulated significantly less VAT as compared with nonexercising controls; and 3) experienced other beneficial changes in total and regional body composition.