The rationale for prescribing exercise after bariatric surgery. Pointed arrows indicate the potential additive effects of exercise and bariatric surgery, whereas blunt arrows indicate the potential for exercise to counteract adverse physiological and metabolic effects that occur after bariatric surgery. In brief, exercise can potentially sustain, or even enhance, the cardiometabolic effects of bariatric surgery, and these include improvements in insulin sensitivity, inflammatory markers and endothelial function. In addition, exercise may also prevent the loss of muscle and bone mass and functionality, that is commonly observed after bariatric surgery.