Full-Body Circuit Training Improves Body Composition and Cardiorespiratory Fitness in Overweight Sedentary Adults – A Randomized Controlled Trial

Obesity and low cardiorespiratory fitness are major risk factors for numerous non-communicable diseases and mortality, and efficient treatment protocols to counteract these conditions are highly warranted. We evaluated the effect of high-intensity circuit training (CIT) on body composition and cardiorespiratory fitness of sedentary overweight individuals. Cardiorespiratory and body composition were assessed before and after a 8-week circuit training (CIT; four sessions of full-body CIT per week; age, 38 ± 9 years old; height, 174 ± 10 cm; body mass, 93.1 ± 22.2 kg; n = 32), and 8-week inactiv-ity (CON; neither training nor lifestyle changes from week; 0–8 age, 39 ± 7 years old, height, 168 ± 8 cm, body mass, 89.5 ± 17.5 kg; n = 33). The two-way repeated-measures ANOVA revealed moderate to large reductions were observed in body mass, BMI, and fat percentage after CIT (d=0.43–0.81; P<0.05). In contrast, all body composition parameters remained stable after 8-week inactivity (P<0.05). A small to moderate group x moment interaction was found for body mass, BMI and % fat (d=0.10–0.60; P<0.05). Small improvements in VO2max were observed after CIT (d=0.48 [0.11–0.85]; P=0.010), while small to moderate reductions were observed in VO2max and PV were observed after inactivity (d=0.47 [0.11–0.83] and 0.64 [0.26–1.01], respectively; P<0.05). A small moment x group interaction was observed for VO2max (d= 0.19 [0.13–0.26]; P