Differential Changes in Exercise Performance After Massive Weight Loss Induced by Bariatric Surgery

Background Exercise performance and pulmonary function are often impaired in severely obese subjects. Bariatric surgery represents the most effective therapy for severe obesity, but data on changes in exercise performance after massive weight loss induced by bariatric surgery have rarely been assessed so far. Methods Exercise performance was obtained by bicycle spiroergometry in 18 severely obese patients before and at least 1 year after bariatric surgery. Additionally, pulmonary function was assessed by spirometry. Results BMI was reduced from 46.3 ± 1.6 to 33.5 ± 1.4 kg/m 2 after surgery. Pulmonary function (forced expiratory volume within 1 s; inspiratory vital capacity) improved after weight loss (both p ≤ 0.01). At peak exercise, heart rate (HR) peak, absolute oxygen uptake (VO 2 ) peak, and load peak did not differ between both assessments (all p > 0.25). However, relative (related to actual body weight) VO 2 peak and workload peak were higher after than before surgery (both p ≤ 0.005), while gross efficiency peak and ventilatory equivalent peak remained unchanged (both p > 0.30). At anaerobic threshold (AT), patients showed lower HR AT and absolute VO 2 AT after than before surgery (both p