You should do it against the clock. Say you are going to do 30 laps in 15 minutes. Then you try to do it each day a little faster. That is putting demands on the body, and that is how you build up. You keep up your energy instead of going downhill.
Jack LaLanneMuscle cells strengthen in response to intense exercise - whether you're 18 or 88. But the intensity is what's lacking in most people's workouts. And there are doctors who'll give you the advice, "Well, don't push it."
Jack LaLanneWho puts the food in your mouth? Who goes to the bathroom for ya? You do. You came on this earth alone and you are going to leave alone. Think about it. If anything happens to Jack La Lanne good or bad, I made it happen. If anything happens to you good or bad, you made it happen - right?
Jack LaLanne