How long does it take to exercise to lose weight? Are you talking about the time of each exercise? It is recommended to exercise for more than 40 minutes each time, within 1 hour. Excessive exercise is also inappropriate. If you are a person who has never been exposed to exercise to lose weight before and rarely exercises, you can slowly add time from 20 minutes to give your body a time to adapt. If it means how long it takes to lose weight through exercise, it depends on your personal situation.