Ask the guys who are doing serious triathlons if there are any limits to what can be done. The limit is right here. You've got to get physically fit between the ears. Muscles don't know anything. They have to be taught.
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 LaLanneIf you take steroids, you have to pay the price. They can kill you; there are no shortcuts. It's like going to bed with a rattlesnake, it's got to get you.
Jack LaLanneI train like I'm training for the Olympics or for a Mr. America contest, the way I've always trained my whole life. You see, life is a battlefield. Life is survival of the fittest... How many healthy people do you know? How many happy people do you know? Think about it. People work at dying, they don't work at living. My workout is my obligation to life. It's my tranquilizer. It's part of the way I tell the truth--and telling the truth is what's kept me going all these years.
Jack LaLanne