Time Magazine had a very interesting cover story last week (dated 8/17/09) about new research questioning whether exercise actually helps with weight loss or even weight control. We've all thought that burning calories at the gym or playing sports as well as doing strength training will help us drop pounds--or at least not gain weight as we age.
The Time article blows some holes in those notions. Researchers are finding that when we do blast some calories through exercise, we end up hungrier than if we hadn't exercised, and can easily eat as much (or more) after our exertion than we would have otherwise. Moreover, other researchers have documented that people who exercise vigorously will go home and slug out, versus those who divide their activity levels more evenly across the day and evening.
My summary doesn't do justice to the article, so I encourage you to seek it out, if interested. The author does stress that exercise is still important for many other benefits besides weight control--one of the main reasons I am an exercise fanatic is that it helps me sleep better, for instance. But it is rather eye-opening and sobering to think that exercise and weight may not be all that closely tied.