Impact of high-intensity interval training vs. moderate-intensity continuous training combined with strength training on physical and metabolic outcomes in post-bariatric surgery patients with sarcopenic obesity

Sarcopenic obesity (SO) is a pathological condition characterized by a decline in skeletal muscle mass accompanied by increased fat accumulation. This condition is associated with a higher risk of physical limitations, cardiovascular diseases, and weight loss failure following bariatric surgery (BS). To identify more effective management strategies for SO after BS, this study aimed to compare the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on body composition parameters, physical performance, and cardiometabolic indicators in patients with SO post-BS. In this study, 80 females with body mass index 40 ≤ BMI ≤ 50 kg/m2 who were candidates for undergoing BS and diagnosed with SO were recruited. Participants were divided into two groups: HIIT (n = 40) and MICT (n = 40), each further subdivided into sleeve (n = 20) and bypass (n = 20). Both interventions were followed over an 8-week period after BS, starting from four to 12 weeks post-surgery. Body composition (Weight, Fat Mass, Skeletal Muscle Mass, and Fat Free Mass), physical performance (aerobic capacity, physical ability, and muscle strength), and cardiometabolic indicators (glycemic indicators, lipid profile, and inflammatory factors) were measured pre and post intervention using body impedance analyzer, standardized functional tests, and blood samples, respectively. A 24-hour food diary was also obtained by conducting an in-person interview for food intake assessment. A total of 80 participants completed the study. Age was a significant covariate (p = .007). After adjusting for age, HIIT significantly reduced weight, BMI, calorie intake, and carbohydrate intake compared to MICT, with the HIIT-bypass group showing significant improvements in HbA1c, insulin, and FBS (mean reduction of 7.71%, 24.98%, and 6.34%, respectively; p < .05). Additionally, HIIT-bypass reduced hs-CRP (mean reduction of 23.81%) and increased HDL (mean increase of 8.88%) (p < .001). In terms of physical performance, while HIIT in both the sleeve and bypass groups significantly improved Sit-to-Stand performance (+ 26.97% for sleeve and + 27.47% for bypass, p < .05), the HIIT-sleeve group showed the greatest improvements in walking speed and balance test (mean increase of 10.33% and 14.59%, respectively, p < .001), whereas HIIT-bypass exhibited the most significant improvement in Timed Up-and-Go (+ 12.21%, p < .001). These findings highlight the superior effectiveness of HIIT over MICT (dependent on the type of surgery) in improving both metabolic and some physical outcomes. Significant differences were observed in cardiometabolic and physical performance parameters between the two training protocols. HIIT resulted in significant improvements in aerobic capacity, physical ability, glycemic indicators, hs-CRP, HDL, weight, BMI, and food intakes compared to MICT. These findings may position HIIT as a promising intervention for optimizing metabolic and physical outcomes in post-bariatric patients with sarcopenic obesity. However, no significant changes were observed in muscle strength or skeletal muscle mass. These findings position HIIT as a promising intervention for optimizing certain metabolic and physical outcomes in this population, though further blinded, randomized controlled trials are warranted to confirm these results. IR.TUMS.THC.REC.1401.052. Current research is a prospective quasi-experimental study, and clinical trial number is not applicable.