Aerobic fitness should be considered a vital sign, just as body temperature, blood pressure, pulse and breathing rates are now, according to a new scientific statement from the American Heart Association.
The statement points out that fitness can be a better indicator of someone’s risk for heart disease and early death than such standard risk factors as smoking, obesity and high blood pressure. The authors recommend that each of us should have our aerobic fitness assessed as part of medical examinations and, if our fitness is on the low side, we should be advised and helped to start exercising.
The authors also suggest that if your physician does not begin to determine your aerobic fitness in the near future, you should do so yourself, using any of several scientifically validated online tools.
Aerobic, or cardiorespiratory, fitness is a measure of how well your body can deliver oxygen to tissues. Because that process is pervasive and essential within our bodies, it is also a “reflection of overall physiological health and function, especially of the cardiovascular system,” according to the report.
Many past studies have found that relatively low aerobic fitness is linked with a significantly increased risk for heart disease and premature death and that being out of shape may, in fact, represent a greater risk for developing heart disease than if you have a poor cholesterol profile, Type 2 diabetes, a history of smoking or a high body mass index.
But in 2013, when the American Heart Association and American College of Cardiology released new guidelines for assessing someone’s risk for heart disease, the criteria did not include aerobic fitness as a risk factor. The agencies were still uncertain about whether enough science existed to justify including fitness and also worried that the treadmill tests needed to measure aerobic fitness were complicated and costly.
But the research was compelling enough that the American Heart Association decided to convene an expert scientific advisory group that would gather and analyze all of the available studies about fitness, heart health and life spans, and also look into the question of whether fitness could be determined accurately and cheaply, without everyone needing to undergo a treadmill test.
In effect, the advisory board was asked to decide whether aerobic fitness should become a new vital sign.
Their answer, delivered in the new statement, which was published simultaneously in Circulation and Professional Heart Daily, a publication of the National Stroke Association, was a resounding yes.
The authors concluded that the available science overwhelmingly supported the use of aerobic fitness as a measure of general and heart health.
Almost as important from a practical standpoint, the authors also determined that newly developed equations and simple calculators could provide reliable, valid estimates of fitness. Doctors could use a few keystrokes to estimate someone’s fitness, instead of ordering a treadmill test (although some people, especially those at high risk for heart disease based on other factors, should still undergo treadmill testing, the authors write).
The resulting scientific statement “strongly supports” the use of cardiorespiratory fitness as a vital sign and “an important measure and predictor of health,” says Steven Blair, a professor of exercise science and epidemiology at the University of South Carolina and co-chairman of the scientific committee.
The statement, which went through peer review, as well as a separate review and endorsement by the standing scientific advisory board for the American Heart Association, is, however, only a recommendation and does not change the current formal heart disease risk calculations.
But the statement’s authors are hopeful that it will have an immediate and lingering impact.
“In general, I think that doctors understand that cardiorespiratory fitness is important,” says Leonard Kaminsky, the director of the Fisher Institute of Health and Well-Being at Ball State University in Indiana and co-author of the statement.
But many physicians “consider it to be relatively less important than other risk factors,” he continues. “Hopefully this scientific statement will be a resource and give them confidence in the solid evidence base for cardiorespiratory fitness as a vital health measure.”
The statement also should be of interest to and practical use by those of us who do not hold medical degrees but do own hearts and lungs, the authors say.
“It would be an excellent idea” for everyone to learn his or her current, estimated aerobic fitness level and how it compares to age-matched averages, says Dr. Chip Lavie, a cardiologist and exercise scientist at the Ochsner Heart and Vascular Institute in Louisiana and statement co-author.
He suggests using an online fitness calculator developed by Dr. Kaminsky and others, based on data from millions of users, at www.worldfitnesslevel.org.
Take the resulting estimate of your fitness age to your next medical appointment and discuss it with your physician, Dr. Lavie says.
In the meantime, if you are concerned about your current fitness, get up and move. Fitness is quite malleable, the statement co-authors point out. You can find a scientifically designed exercise program to improve cardiorespiratory fitness here, at the website of the Norwegian University of Science and Technology: ntnu.edu/cerg/regimen.