This is a myth, one I used to believe, until I started exercising to just improve my cardiovascular health. Lo and behold, I started losing fat unintentionally (my weight only dropped a little, but I think my body composition is better as well, so some muscle was gained).
My weight lifting doesn't burn many calories, but I typically burn 2000-3000 calories a week running. This is close enough to my basal metabolic rate that it is calorically equivalent to fasting one day per week. This is more exercise than is typical, granted, but it does suggest that one can exercise off calories and it doesn't take all that much time to make a dent.
I will say, this kind of caloric burn ups my appetite and I'm not trying to lose weight, so I eat more to compensate.
My weight lifting doesn't burn many calories, but I typically burn 2000-3000 calories a week running. This is close enough to my basal metabolic rate that it is calorically equivalent to fasting one day per week. This is more exercise than is typical, granted, but it does suggest that one can exercise off calories and it doesn't take all that much time to make a dent.
I will say, this kind of caloric burn ups my appetite and I'm not trying to lose weight, so I eat more to compensate.