At some point in the past, we were all in good shape. For the most part, kids are fit. Generally, kids don't have to workout to be fit. Then we grow up. As adults, if we don't pay attention to fitness, there is a fitness drop-off. Studies have consistently demonstrated that muscular strength declines approximately 5% per decade for the untrained individual. What's a busy person to do?

For many people, the possibility of exercising brings up all kinds of memories and associations, not all of them empowering. People tell themselves, "I'm overweight", "I haven't exercised in years", "I don't have the time", "I'm too old", "I don't like to exercise", "I'm fine the way I am", "I'm embarrassed to go to the gym", and so on. With these conversations going on under the surface, there is no way that anyone will start exercising if they are told to do it. I know that you won't start training just because I said so, just because I recommended it. The will to begin comes from you, the person who will be the one working up the sweat. It's your choice, and ultimately you're the only one who can make this choice. One question to ask is, "What type of exercise would I like to do?" There are many types of exercise, each possessing particular value. In general, exercise that has an aerobic quality packs the most punch, provides the most overall benefit. Aerobic exercise includes the following:

• Aerobic exercise classes
• Running
• Brisk walking
• Bicycle machines or brisk cycling
• Stair-climbing machines

People are funny about exercise; they know they should be doing it and feel guilty if they don't, or haven't in a long time. Let's tell the truth about exercise: most of us are not doing it, we know we should, we may even want to and regret the fact that we're not, and we simply don't know how to begin.

Here's how to begin: pick the form of aerobic activity that you think you might enjoy and start doing it. Start today, do some, not too much, and do some more tomorrow. Then wait a day and do some the next day. Just like that, keep going. Soon it will become a routine.

Now it's not quite that straightforward. You will want to quit. Other things to do will look like they're more important or more urgent than your planned exercise. But if you do what you said you'd do you'll experience a great sense of accomplishment. Besides that, exercise actually feels good, or at least it does after you have gained some exercise experience. Doing the exercise that you'd planned lays a brick in the foundation of your fitness program. The more you do the more you want to do. Your body begins to crave exercise, even after just doing some for a few days. Our bodies were designed for hard physical work, but we don't do too much of this any more. Most of us don't hunt; neither do we gather. Exercise awakens these dormant systems and initiates a cascade of responses. You begin drinking more water. You fall asleep much more easily and sleep more deeply and well.

Instinctively you begin to eat better: food low in nutritive content becomes less appealing; you become drawn to things like fresh fruit and multigrain breads. Your eyes gain sparkle and your skin acquires sheen. You actually stand taller. Your step is more lively, because you are that much more alive. You are using your body in a manner that is familiar to it, even though the activity may be rather unfamiliar to you.

Exercise regularly and consistently. Three times a week is a great place to begin. Half an hour, three times a week. Boom. You're now a person who exercises. You will begin to want to exercise, to be missing it when you're not, and to be ensuring that your schedule specifically includes exercise time. Skill and mastery follow, over time.

Dr. David Lemberg, the author of Commitment to Fitness: Real Fitness for Real People, is a board-certified chiropractic orthopedist in his twentieth year of private practice on Manhattan's Upper East Side. He has been published in national trade magazines such as Muscle & Fitness and Dancemagazine, the peer-reviewed Topics in Clinical Chiropractic, the Florida Chiropractic Society Review, and The Chiropractic Journal. Dr. Lemberg is a member of the postgraduate faculty of Los Angeles College of Chiropractic, and for the last ten years has taught orthopedics to chiropractors in venues across the United States and in Canada. He was Clinical Editor of the quarterly journal, Spinal Manipulation, published by the Foundation for Chiropractic Education and Research, from 1990 through 1995.

Commitment to Fitness: Real Fitness for Real People may be ordered through Dr. Lemberg's web site. His office is accepting new patients: 212-535-7429.