Exercise capacity is a key element in your health regimen

Filled to Capacity

If you go out of your way to eat a nutritious, balanced diet of whole foods and then add some insurance with a selection of vitamin and mineral supplements, all of your good efforts will be compromised if you don’t address one more key element in your health regimen.

If you jumped ahead of me and guessed that I’m talking about exercise, you’re half right. The key element: exercise capacity (EC).

Your chances of living a long and healthy life increase as your exercise capacity increases. This was the finding of a study I told you about more than three years ago, and its now been confirmed by a new study. The difference this time: That previous study involved only men; this one was just for women.

Measuring up

Your exercise capacity is a measure of your fitness level. In simplest terms, if you exercise regularly, your ability to exercise increases. In the 2003 study of EC in men, researchers from Stanford University judged exercise capacity to be the most reliable predictor of lifespan.

Coincidentally, that study and the newest one were both published in the New England Journal of Medicine. The one that appears in last week’s issue of the journal comes from Rush University Medical Center in Chicago where more than 5,700 healthy women took stress tests to measure their metabolic equivalents, or METs. (One MET is equal to the amount of oxygen used by the average person when seated. Two METs roughly equates to walking at a rate of less than two miles per hour, while eight METs represents the oxygen used while jogging at a speed of six miles per hour.)

The Rush researchers also gave stress tests to more than 4,400 women who had symptoms of cardiovascular disease. Subjects in this group were followed for five years to determine survival rate, and subjects in the healthy group were followed for about eight years.

When the data was examined, the Rush team determined that women whose exercise capacity was measured at less than 85 percent for their age group were twice as likely to die prematurely compared to women of the same age whose EC was 85 percent or higher. This 85 percent cutoff was the same for both the healthy women and the women with heart disease.

In order to measure your METs and determine your exact exercise capacity you’ll need to consult an exercise counselor. Many gyms and exercise clubs have equipment that will display METs information.

But for our purposes let’s keep it simple: When you exercise on a regular basis, your exercise capacity goes up and risk of premature death goes down.

One step at a time

So do you need to run two miles each day and take an intensive aerobics class several times a week to improve exercise capacity?

No way.

In the 2003 study of exercise capacity in men, the Stanford researchers reported that even small improvements in exercise capacity reap substantial benefits. As the study’s authors put it, “Among subjects with cardiovascular diseasewe observed a near linear reduction in risk with increasing quintiles of fitness.” In other words, each small step in the improvement of fitness, no matter how slight it may seem, may help prevent premature death.

Stanford researcher T. Edwin Atwood told CNN: “It’s not how long you exerciseIt doesn’t take marathons or running. Walking briskly every day for half an hour is a great risk modifier.”

Sources:
“The Prognostic Value of a Nomogram for Exercise Capacity in Women” The New England Journal of Medicine, Vol. 353, No. 5, 8/4/05, content.nejm.org