06/24/2014 06:03 pm ET Updated Aug 24, 2014

Dare to Be 100: Exercise as Rheostat

I am a lifelong fervent advocate for the intrinsic value of physical fitness for the world's biggest health challenges, globesity and aging. I always seek a metaphor to plead my cause.

I have labeled exercise as the oboe's A, as armor, as an essential gene, as a pilot light, as a metronome. More meaningfully, however, is my label of exercise as an insurance policy. In this context I have lobbied the top management at United Health in Minneapolis to provide cheaper health insurance policies to fit persons. I resent subsidizing the costs of sedentary individuals. Their response: "We will, IF you will give us a sturdy biomarker to guarantee return on such an investment.

Fair enough. Since America is sternly ruled by money, exercise fitness must pay. I continue to work on the challenge of a bio-marker with Dr. Chirag Patel, now recently relocated from Stanford to the Harvard School of Public Health. We are collectively mining many data sources to provide the evidence of the cost/benefit of physical fitness. This is a vitally important work in progress.

I have resisted the embrace of the term "exercise as medicine." This metaphor is energetically spurred by the American College of Sports Medicine, of which I am a loyal member. It is spearheaded by Dr. Bob Sallis of San Diego. Bob is a terrific speaker and guy. I had him speak to our Stanford medical students on his pet project of exercise as medicine.

I am totally in line with the intent of this campaign, yet I resist the term, as to me it is commoditized. It tends to frame exercise as a medical feature, about one that has to do with fixing what is wrong, as a repair function.

I agree that exercise is a good treatment for almost everything, but much more importantly it is a preventive. I subscribe to what Oliver Wendell Holmes wrote: "The shield is nobler than the spear." True, we need spears, but we need shields more. We need a gigantically-emphasized preventive public policy now. We know enough to prevent almost everything. Fitness is the central strategy for this, particularly as we age. Fitness is required, not optional.

Without it, we will all become broke and institutionalized. This is not a prospect that any of us would welcome.

Therefore, I offer rheostat as a new metaphor for exercise: Not too hot, not too cold. Just right for lifelong health.

Any metaphor that works for you works for me and for the rest of us.

Just DO IT!