Not Doing The Things That Make You Strong Has Its Consequences
(By Mark Rippetoe; author of Starting Strength: Basic Barbell Training, Practical Programming for Strength Training, Mean Ol’ Mr. Gravity, and many other articles)
When you consult a medical professional about exercise, the standard recommendation amounts to a prescription for a certain number of minutes per day or per week. The conventional wisdom equates “exercise” with “cardio” — endurance exercise performed at a low to moderate intensity for a continuous period of time. We call it LSD (long, slow distance). The assumption seems to be that as long as your heart is capable of working at 65% of its assumed maximum capacity, that’s about all you need to do.
The fact is that a properly designed strength training program constitutes a much better use of the same amount of time a “cardio” workout takes, and provides far more benefits to your quality of life. This is especially true if you are older.
Assuming you are not a heart patient, strength training provides enough cardiovascular work to serve the purpose, and produces an increase in strength that endurance exercise cannot provide. Here’s why:
Not doing the things that make you strong has its consequences.
Increased strength is produced by activity that requires you to use your muscles to produce force — more force than you normally produce in daily activities, and more force than LSD requires. When you use your muscles in an effective strength program, sugar fuels the activity, and efficient carbohydrate metabolism is necessary for your health. A lack of active carbohydrate metabolism is very closely correlated with the development of Type II Diabetes and other unpleasant things. Type II Diabetes shortens your lifespan, in addition to making your shorter life a lot more trouble.
This cannot be emphasized enough: using your muscles in a way that makes them stronger also improves the way your body handles the sugar that can cause metabolic problems like diabetes.
When the human body is allowed to sit on its ass instead of doing the muscular work that keeps it strong, it is being placed in a situation that its physiology is not designed for. Muscular activity is natural. Inactivity is not. Intellectual pursuits notwithstanding, doing the things that keep you strong may well be the most important things you do.