The Value of Moderate Exercise

The image and standard of vigorous, sweat-soaked exercise has discouraged many sedentary individuals from even trying to become more active. The bulk of benefit may come from expending as little as 500 calories a week in moderate physical exercise. And such activity need not be an arduous bout of exercise, but can be pleasurable, enjoyable activities: talking, gardening, bowling, dancing, golf, and so on.

Just What is the Effect of Exercise on the Muscles?

Weight training exercise (called progressive resistance training) causes the muscles to get bigger and stronger. Further, increased muscular strength will give you more resistance to injury and will slow down the loss of muscle mass that nonexercising people experience as they get older. Aerobic exercise (progressive endurance training) increases blood flow, oxygen, and nutrients to the muscles being exercised.

Other benefits include improved appearance because your muscles will have tone — you’ll look better and feel better. Your body will be more firm and you’ll look younger. (As you get older, your body actually loses muscle — so-called fat-free weight — unless you exercise the muscles.)

The Overload Principle

Weight training is a part of just about every sport these days, from baseball to swimming to golf. Practically every serious and/or professional athlete knows about the overload principle:

But how does this apply to you? Even though you’re not a pro, the same principle applies to anyone who lifts weights.

To “overload” a muscle simply means that you stress the muscle in intensity or duration beyond the demands of previous activity. This is then followed by a rest period in which the muscle will rebuild with greater strength and endurance. (See p. 85 on the importance of a day of rest.) The body does this by programming the cells to rebuild stronger so they can handle greater stress the next time. (It’s one of the amazing automatic processes of the human body.) As your muscles adapt to the increased stress, you must overload them even more for further gains.

In 300 b.c., Milo of Croton demonstrated this principle — now called progressive resistance training — by hoisting a calf on his back every day until it became a full-grown bull.

How Hard Should You Work Your Muscles?

You should work hard enough to bring the overload principle into effect (if only slightly), but not hard enough to get exhausted or injured. In other words, take it easy. The surest way to make progress is to do so gradually. The key word is progressive resistance (or endurance) training.

from: Getting In Shape © 2002
by Shelter Publications, Inc., Bolinas, CA