Concurrent Exercise Effects in Post-Bariatric Patients

This study aims to evaluate the effect of a 5-week concurrent exercise program (aerobic and resistance training) on muscle quality, body composition, functional response, and quality of life in individuals undergoing bariatric surgery. This is a single-center, prospective, longitudinal, non-randomized controlled clinical trial with two groups: intervention and control. A total of 84 adults aged 18 to 60 years who have undergone sleeve gastrectomy or gastric bypass and have a medical indication for metabolic rehabilitation will be recruited. The intervention group will complete a supervised concurrent exercise program for 5 weeks, consisting of two in-person sessions per week (10 sessions in total), while the control group will continue with usual care without participating in a structured exercise program. All participants will be assessed at two time points: baseline (postoperative week 4) and 7 weeks after baseline (after 5 weeks of intervention and 1 week of rest). The primary outcome will be muscle quality of the rectus femoris assessed by ultrasound (echo intensity). Secondary outcomes will include body composition (bioelectrical impedance analysis), functional performance (one-minute sit-to-stand test), and quality of life (Moorehead-Ardelt II questionnaire). Additionally, adherence to the exercise program in the intervention group will be evaluated as the percentage of attendance to supervised sessions, and its association with the magnitude of changes in outcomes will be analyzed under a dose-response framework. The results are expected to provide clinically relevant evidence on the effectiveness of exercise in the early postoperative period and to support the optimization of metabolic rehabilitation strategies after bariatric surgery.