Effect of High-Intensity and Concurrent Training in Body Composition in Costa Rican Overweight and Obese Women

This study was designed to determine the changes in body composition, Body Weight (BW), Fat Mass (FM), Body Fat Percentage (BF%) and, Skeletal Muscle Mass (SMM) of High Intensity Interval Training (HIIT) and Concurrent Training (CT), comparing them to a Control Group (CG) for four months of intervention in overweight and obese women. Methodology: 67 obese and overweight women (37.54 ± 8.8 years, BMI = 28.49 ± 4.9, BF% = 43.63 ± 5.6%) were randomly assigned to three groups, HIIT (n = 26, mean age = 37.9 ± 7.3 years, BF% = 42.36 ± 4.3%), CT (n = 20, mean age = 38.0 ± 8.5 years, BF% = 45.98 ± 5.4%) and CG (n = 21, mean age = 36.6 ± 11.0 years, BF% = 42.97 ± 6.8%). Before and after 16 weeks of HIIT (intervals at ≥ 80% Maximal Heart Rate) and CT (strength training, 65%-75% 1RM + endurance training, 60%-80% Maximal Heart Rate), participants underwent Dual-Energy X-Ray Densitometry (DEXA). The CG did not exercise at all. Results: There were no changes in BW among the experimental groups (p > 0.05). Compared to CG, the HIIT and CT groups decreased FM, BF% and increased SMM (p < 0.05). CT was better than HIIT on FM (relative change, Δ%, HIIT = -3.4% vs. CT = -4.5%), BF% (HIIT = -2.6% vs. CT = -4.3%) and SMM (HIIT = +1.7% Vs. CT = +5.4%). Conclusion: Findings show improvements of body composition in overweight and obese women. In this context, although the results were not highly marked, CT seems to be a better approach for the prevention and management of the women overweight and obesity than HIIT.