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 highintensity 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 inactivity (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<0.001). Our findings suggest that 8-week of full-body circuit training may improve cardiorespiratory fitness and body composition in sedentary overweight individuals.