For 43 years I have studied human performance and how it can be enhanced. I've worked with world-class champions to improve their speed or power or skills, I've helped executives develop their energy and concentration; I've designed a program to maintain the fitness of America's astronauts in space, on the moon and during their eventual trip to Mars.

But nothing I have done has in any way changed my bias against structured exercise. What I've learned has only deepened that bias.

Most Americans share my feelings - women in particular. It's apparent that at leat 30 percent of the adult population isn't exercising sufficiently or properly to arrest physiological decay.

In their resistance to exercise, Americans show a certain amount of commendable intuitive sense. Exercise, as it is generally taught and practiced, is not simply boring it is punitive, dangerous and ineffective.

Exercise programs are often so rigorous that those who attempt them are injured. The goals of fitness are placed beyond the average person's reach. The mystique fostered by the fitness cult encourages the belief that good physical condition comes slowly, that work to exhaustion is necessary, that the process requires special equipment space, supervision, and an abundance of time. It's all nonsense.

But exercise shouldn't be hateful, punishing, interminable and dull. It needn't be aby of these.

Fitness is a piece of cake. You can achieve and maintain fitness in just twice the amount of time you require to brush your teeth. You need about 15 minutes a week to brush your teeth. You need about 30 minutes a week to be fit.

But first let me tell you what you won't have to do to stay fit about it. Quit exercising and try agin tomorrow or the next day.

You don't have to eliminate foods or beverages of any kind. Diets that restrict the kinds of food you can eat or that grossly curtail your intake are inhuman, injurious, and doomed to fail. If weight loss is your goal, you can do it on a wide-variety diet.

You don't have to run a certain distance or race against a clock or lift so much weight so many times. It will be a goal that reflects your condition, your capacity for physical effort, and your needs and objectives.

All previous exercise programs measure the work you produce - the distance you run or the speed at which you run it or the number of times you can accomplich a specific task. These programs are interested in only one thing - the effect you produce on your body. You regulate that effect entirely. You produce exactly the response to the effor you wish and require.

Heart rate and pulse rate technically are separate phenomena, but the differences for our purpose are not significant. Your pulse tells you how fast your heart is beating.

With five minutes training, you can learn to interpret your own well-being by taking your pulse. Your normal rate may be extremely fast or extremely slow compared to the norms - and yet be normal for you. However it, beats ar rest, it's your pulse rate during exercise that enables you to structure your fitness program exactly to your requirements. Your pulse rate is your individualized guide to fitness.

This program applies equally to men and women. The only persons who shouldn't attempt it are those whose doctors have forbidden exertion or who fail the pulse test. Beyond that, the program is open regardless of age or physical conditions.

Those who are in the worst shape, in fact, will show the most dramatic and rapid improvement. If you haven't exercised once in the last 20 years, you are nonetheless just two hours away from good physical condition relative to the condition you were in when you began.

At the end of 12 hours, you'll be in excellent shape by any standards. You'll look and fell youngr. Your waist will be thinner, your hips and thighs firmer. And you'll be permanently rid of many pounds of fat.

Those hours represent the cumulative time of three hours of exercis a week of 10 minutes each, during three couses of eight weeks each. You can do more if you wish. BUt the data say that you don't get much more good out of exercising every day than you do from exercising every other day.

This is one program that discourages overzealousness.

There's no reason not to be in shape. It's so easy. It takes so little time. The response you get from the slightest amount of exercise is so great that you're immediately rewarded with a feeling of increased well-being. WIth exercise, you're livelier longer. The period during which you're half-dead is recuced. And you reduce the prospects of premature death.

"We'll start with what you can do no matter how little that is. Each day, you'll do just a little more, but so little that you'll scarely notice. This all but infinitestmal increase is know as "overload." It's the foundation of pulse-rated exercise and the key to its success.

I repeat I hate formalized, rigid, punitive exercise. I hate it all the more now that I have the science to support my instinctive knowledge that it simply isn't necessary.