Effects of Whole-Body High-Intensity Interval Training on Cardiorespiratory Fitness, Musculoskeletal Fitness, Body Composition, and Metabolic Biomarkers in Adults with Overweight and Obesity.

Background/

Objectives

Identifying accessible and effective exercise interventions is essential for improving health and physical fitness in individuals with overweight or obesity. Whole-body high-intensity interval training (WB-HIIT) is a time-efficient approach that requires minimal equipment and can be adapted to a wide range of settings and fitness levels. Therefore, this study aimed to investigate the effects of WB-HIIT on cardiorespiratory and musculoskeletal fitness, body composition, and metabolic health markers.

Methods

Thirty-six healthy adults with overweight were assigned to either a WB-HIIT group (n = 19; 35 ± 9 years; BMI 30.2 ± 3.1 kg/m2) or a control group (n = 17; 33 ± 11 years; BMI 30.3 ± 3.3 kg/m2). Participants completed pre- and post-intervention assessments including dual-energy X-ray absorptiometry (DXA), blood sampling, maximal cardiopulmonary exercise testing, and measures of muscular strength (3 RM) and functional endurance (1 min sit-to-stand and arm curl). The 10-week supervised WB-HIIT (2-3 sessions per week) included a warm-up, 3-4 sets of 10-12 all-out whole-body exercises (30-40 s) interspersed with 20-30 s recovery, and a cool-down.

Results

The control group showed no significant changes in any of the assessed parameters after 10 weeks, except for a modest increase in body fat mass. The WB-HIIT group showed significant improvements in cardiorespiratory fitness, evidenced by increases in VO2peak (p < 0.05), maximal treadmill incline (p < 0.01), and first ventilatory threshold parameters (p < 0.05). Maximal strength increased significantly in both the leg and bench press (p < 0.001), accompanied by a significant improvement in upper-limb functional endurance (arm curl, p < 0.05). No significant changes were observed in body weight or BMI, but small reductions were found in body fat percentage, trunk fat mass, and waist circumference (p < 0.05). Except for a modest decrease in glycated hemoglobin (p < 0.05), metabolic blood parameters remained unchanged and were already within the normal range at baseline.

Conclusions

A 10-week WB-HIIT intervention improved cardiorespiratory fitness, muscular strength, and upper-limb functional endurance, and elicited a modest reduction in trunk fat mass in individuals with overweight or obesity.