This is the advice I always give to people who are trying to lose weight from counting calories (which is really the only way to do it of course). I say, "Never count your exercise. If you walk for half an hour, lift weights for an hour, swim laps for twenty minutes, just think of it as like a bonus. Just because MFP says you burned 500cals from walking doesn't mean it's true, it's impossible for it to know. It's always waaaaaaay over estimating. I spend two hours 4x a week at the gym and have a very active job, but MFP thinks I sit on my ass all day eeryday."  And then fatty is like, "BUT THEN I'LL LOSE TOO MUCH AND BE UNHEALTHY REEEEEEEEEEEEE"