High Intensity Circuit Training Versus Moderate Strength Training On Body Composition In Obese Adults

Abstract

Weight loss has been shown to adversely affect body composition due to the loss of fat free mass that accompanies fat mass loss during negative energy balance. Exercise has been recommended as a therapy to ameliorate fat free mass loss during weight loss interventions. PURPOSE: The primary purpose of this study was to compare the effectiveness of high-intensity circuit training (HICT) versus moderate strength straining (ST) on body composition in obese adults. METHODS: Obese adults (10 women and 1 man) completing a medically supervised weight loss program were randomized into one of two 12-week exercise training groups: HICT (n=5) or ST (n=6). Baseline (BL) testing included height, weight, and DEXA scans to assess total and regional body composition. Each group underwent a supervised exercise training program of upper and lower body exercises (30 minute sessions; 3 times per week for 12 weeks); follow-up (FU) testing was performed after 12 weeks. The HICT consisted of 8-12 exercises of 2-3 sets, with rest periods of approximately 30 seconds. Exercise intensity corresponded to 80-95% of their VO2peak. The ST group completed progressive resistance training which included 2-3 sets of 10-12 repetitions of each exercise. RESULTS: When examining changes in body mass index (BMI), total fat mass (FM), total fat free mass (FFM), trunk fat mass (TFM) , and estimated visceral fat mass (VFM), mixed model ANOVA revealed no significant group x time interaction (p>0.05) nor a main group effect (p>0.05) for the variables. However, there was significant time (BL vs FU) main effect for BMI (38.7 ± 1.5 vs. 33.1 ± 1.7, respectively, p<0.001); FM (48.4 ± 4.0 vs 38.7 ± 3.8 kg, respectively, p<0.001); TFM (26.1 ± 2.1 vs. 19.6 ± 1.8 kg, respectively, p=.001); and VFM (1.5 ± .19 vs. 1.0 ± .13 kg, respectively, p=.001). CONCLUSION: Both the 12- week HICT and ST program in conjunction with the medical weight loss program produced successful weight loss and FM changes. Furthermore, FFM was retained in both groups, suggesting both programs are viable options to improve or maintain body composition through substantial weight loss.