Effects of Resistance Training on Obese Adolescents.

Purpose: The effects of resistance training (RT) alone upon endothelial function, metabolic and hemodynamic profiles, physical fitness, body composition, and inflammatory biomarkers in nondiabetic obese adolescents were investigated.

Methods: Adolescents were assigned into nonobese control (CG, n = 20; 14.7 ± 1.4 yr) and obese (OB, n = 24; 14.1 ± 1.0 yr) groups. Muscle and skin endothelial reactivity, body composition, at-office and 24-h ambulatory blood pressure, metabolic profile, adipocytokines, aerobic and strength fitness were assessed before and after 12 wk of RT (CG, only at admission).

Results: After RT, body mass did not change in OB, but significant reductions in body fat (1.6%; P = 0.01), waist circumference (2.9%; P < 0.001), waist-to-hip ratio (3.3%; P < 0.001), homeostasis model assessment for insulin resistance (15.4%; P = 0.02), endothelin-1 (14.2%; P = 0.04), and fibrinogen (6.9%; P = 0.03) were found. Both at-office and ambulatory blood pressure decreased, whereas skin endothelium-dependent vasodilation (32%; P = 0.02), VO2 (14.3%; P = 0.04), and HR (5.3%; P = 0.04) during submaximal exercise and isokinetic strength (extension, 21.3%; flexion, 29.9%; P < 0.0001) increased. Forearm vascular conductance increased at rest (28.1%; P = 0.03) and during postocclusive reactive hyperemia (25.2%; P = 0.02). After RT differences between CG and OB at admission were no longer detected for most outcomes.

Conclusions: RT alone improved endothelial function, hemodynamic and metabolic profiles, body composition, and physical fitness in nondiabetic obese adolescents regardless of changes in body mass.