Want to lose weight with exercise? You're looking at 300 minutes a week We’re sorry, this service is currently unavailable. Please try again later. Dismiss Want to lose weight with exercise? You're looking at 300 minutes a week By Gretchen Reynolds Normal text size Advertisement Can exercise help us shed kilos? An interesting new study involving overweight men and women found that working out can help us lose weight, in part by remodelling appetite hormones. But to benefit, the study suggests, we most likely have to exercise a lot — burning at least 3000 calories a week. In the study, that meant working out six days a week for up to an hour, or around 300 minutes a week.