Cardiologists at Johns Hopkins University School of Medicine have devised a formula that estimates an individual's risk of dying based on their ability to exercise on a treadmill.
In a new study published in the journal Mayo Clinic Proceedings, researchers analyzed data from 58,000 heart stress tests and created an algorithm to gauge mortality risk over a decade based solely on treadmill exercise performance. While exercise-based risk scoring systems for short-term mortality exist, they are only used for patients with established heart disease or overt signs of cardiovascular trouble. This new algorithm, the FIT Treadmill Score, is applicable to anyone.
"The notion that being in good physical shape portends lower death risk is by no means new, but we wanted to quantify that risk precisely by age, gender and fitness level, and do so with an elegantly simple equation that requires no additional fancy testing beyond the standard stress test," lead investigator Dr. Haitham Ahmed, a cardiology fellow at the Johns Hopkins University School of Medicine, said in a news release.
The FIT Treadmill Score factors in age, gender, peak heart rate reached during intense exercise and the ability to tolerate physical exertion. The last factor is measured by metabolic equivalents (METs), a gauge of how much energy the body expends during exercise. More vigorous activity requires higher energy output (higher METs), better exercise tolerance and higher fitness level, according to the news release. For example, slow walking equals two METs, but running is eight METs.