Get access to everything we publish when you sign up for Outside+.
That article received a lot of attention because it told a very politically incorrect and unpopular truth: Exercise alone isn’t a terribly efficient way to lose weight.
However, the article did not say that exercise wasn’t important for health. Obviously, it is. People who exercise have a lower risk of heart disease, diabetes and even cancer. According to research at the University of Pittsburg, exercise can protect and perhaps even “grow” new brain cells. It can and does improve mood. And – listen carefully – it’s almost impossible to keep weight off if you don’t exercise regularly.
But exercise alone – without a change in diet – is usually doomed as a weight-loss strategy. Consider this: If you burn a very respectable 500 calories in one hour of moderately intense exercise, you can eliminate any weight-loss benefit from that effort by eating one large muffin; and the benefit from running for a half-hour can be wiped out by one mocha Frappuccino.
What the Time article pointed out is that exercise frequently makes people hungry, and because they’ve exercised, they think it’s OK to “indulge” a bit. They wind up overestimating the number of calories they burned and underestimating the calories they consume afterwards. The result? They get the health benefits of exercise, but the pounds stay on their hips.
This hardly means you shouldn’t exercise. Data from The National Weight Control Registry, which tracks people who have lost at least 30 pounds and kept it off for at least one year, is clear that regular exercise (almost daily) is one of the most effective ways for maintaining a healthy weight. But we need to be careful about buying into the belief that just because we exercise for 30 minutes we can eat anything we want.
As trainers like to say, “You can’t out-train a bad diet.” The bottom line is that in order to lose any weight – and to keep it off – you need both exercise and a healthy diet. Exercise alone, unless you’re training for the Olympics, usually won’t do it. So, be sure to eat a consistently clean diet, too.