Four to six hours. According to Sohu News, the principle of weight-loss training camp is to adopt moderate and small intensity, whole-body aerobic exercise and reasonable healthy diet to achieve weight-loss effect, taking into account psychological and living habits, which should at least include exercise courses, nutritious meals and mental health, and 4 to 6 hours is a reasonable exercise time. So the devil training course in the weight-loss training camp is 4 to 6 hours.