It’s an old chestnut of the fitness industry, the notion that for every 3,500 calories you burn you’ll lose a pound of fat. As a personal trainer, though, I often see people slogging through week after week of running, walking, lifting, whatever-workout designed specifically to reach that 3,500 calorie per week mark-only to weigh exactly the same when it’s over. What gives?
The problem with that old weight-loss formula, researcher’s now say, is that it doesn’t take into account what might be happening when you’re not exercising: the calories you would have burned anyway, the calories you’ll add from overeating after overtraining, and the ones you won’t burn the next day because you’re too sore to move.
The old weight-loss math assumed that your body was like a block of marble and that by systematically chiseling away at it with exercise you could gradually get rid of the undesirable stuff and end up with Michaelangelo abs. But your body’s not a block of marble, it’s in a constant tug-of-war between consuming and burning calories, whether you’re eating, sleeping, reading, or watching TV. So the calculus for getting rid of that pound is far more complex than just subtracting the "calories burned" number from your weekly goal at the end of each workout.
The bottom line: You’ve got to exercise more than you thought!!
Source: Mens Journal Magazine