To benefit from exercise, you need to perform some form of aerobic exercise at least three times a week for a minimum of 20 minutes per session. However, more than 20 minutes is better if you want to actually lose weight. Incorporating just 15 minutes of moderate exerciseÃƒÂ¢Ã¢â€šÂ¬Ã¢â‚¬Âsuch as walking one mileÃƒÂ¢Ã¢â€šÂ¬Ã¢â‚¬Âon a daily basis will burn up to 100 extra calories (assuming you donÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢t consume excess calories in your diet afterwards). Burning 700 calories a week equals 10 lbs. of weight loss over the course of a year.