I work out twice a week doing deadlifts, squats, etc... but i'm not gaining weight or bulking up. I'm pretty sure I have less than 2% bodyfat, i'm 6"0 and 130 lbs, I've been exercising frequently (at least once or twice a week) for the past two years. It's just that my metabolism hasnt slowed down yet, i'm still growing, i shit once to twice a day.