Shortfall, from Adi Schnytzer
The doc who runs the "real age" site at the University of Chicago was once asked whether sex could replace exercise. He opined that if you could have 120 or so orgasms a week, you wouldn't need to do any other exercise! This is a tough one, of course. My wife and I keep getting tired after about 100 and we have to do some rowing to make up the shortfall. (Just kidding - we don't row!)