Cutting calories. It's a good idea to exercise whether or not you need to lose weight. Exercising probably won't help you lose weight, but once you've lost it, exercising will help keep the weight off -- which is the ultimate goal. Physical activity guidelines for americans recommend that adults do 30 minutes of moderate-intensity activity (like brisk walking) 5 days a week. To keep weight off more is better.
Many. Remember exercise can keep you from gaining weight but not necessarily lose weight if you are not eating properly. High intensity interval training burns fat. Make sure you are medically cleared to do so. For instance a 20-30 min elliptical interval program where first 5 is warm up, next 20 you increase work load or speed the last 15-20 seconds each minute then return to baseline. Burns fat!