Myth #5: Aerobic exercise tends to make you hungry, so it actually undermines your efforts to lose weight.

Truth: Aerobic exercise, such as jogging or brisk walking, may indeed increase your appetite - but only, it seems, if you need extra calories. Studies suggest that lean individuals do get hungrier after such exercise; that helps prevent them from getting too thin. In contrast, working out does not seem to boost appetite in obese individuals; so exercise should help them slim down.