This article appears in the Nov. 3, 2013 issue of The New York Times Magazine.
Trying to quantify your aerobic fitness is a daunting task. It usually requires access to an exercise-physiology lab. But researchers at the Norwegian University of Science and Technology in Trondheim have developed a remarkably low-tech means of precisely assessing aerobic fitness and estimating your “fitness age,” or how well your body functions physically, relative to how well it should work, given your age.
The researchers evaluated almost 5,000 Norwegians between the ages of 20 and 90, using mobile labs. They took about a dozen measurements, including height, body mass index, resting heart rate, HDL and total cholesterol levels. Each person also filled out a lengthy lifestyle questionnaire. Finally, each volunteer ran to the point of exhaustion on a treadmill to pinpoint his or her peak oxygen intake (VO2 max), or how well the body delivers oxygen to its cells. VO2 max has been shown in large-scale studies to closely correlate with significantly augmented life spans, even among the elderly or overweight. In other words, VO2 max can indicate fitness age.
In order to figure out how to estimate VO2 max without a treadmill, the scientists combed through the results to determine which of the data points were most useful. You might expect that the most taxing physical tests would yield the most reliable results. Instead, the researchers found that putting just five measurements — waist circumference; resting heart rate; frequency and intensity of exercise; age; and sex — into an algorithm allowed them to predict a person’s VO2 max with noteworthy accuracy, according to their study, published in the journal Medicine & Science in Sports & Exercise.