A: Weight does not determine hours of exercise. Regardless of size, it is very important for cardiovascular health that you exercise 30 minutes 5-6 days a week. If you are trying to lose weight you will need to exercise for an hour or more. Vigorous exercise needs to be 30 minutes a day. This does not need to be 30 continuous minutes of exercise; it can be three 10-minute workouts or six 5-minute vigorous workouts.
If you are obese, it may be easier on your joints to workout in the water. Swimming or water aerobics are a great way to exercise and lose weight. Treadmills can be very hard on the knees so if possible, try to walk outside or in the mall.