I managed to balloon up to over 350 pounds while swimming a mile several times a week. I have always been active, but that didn't control my weight. IMHO, the key to weight control is what you eat. However, exercise is very important for over-all health, particularly cardiovascular health, and is something we need to do. It also helps you to maintain your muscle tone as you lose weight, so you don't get flabby.

Personally, I love to exercise and I just feel better when I do it!