Ever wonder if you’ll be alive one decade from now?
Well, barring accidents and similar fatal misfortunes, cardiologists at Johns Hopkins say they can make a calculated prediction using two simple tools—a treadmill and a heart rate monitor.
The new formula, named the FIT Treadmill Score, is described in the March issue of the journal Mayo Clinic Proceedings. It factors in a person’s age, gender and ability to exercise on a treadmill at an increasing incline and speed. The resulting score correlates with a person’s 10-year risk of dying from any cause—patients who scored highest on the test (the most physically fit) had a 2 percent risk of dying, while those with the lowest scores had a 38 percent risk.
This is not the first exercise-based risk test to be developed—the Duke Treadmill Score is one commonly used example. But what makes the FIT Treadmill Score unique is that it’s meant for healthy people and is based solely on fitness. Previous tests were designed for patients with existing heart disease and required inputs from more high-tech equipment like electrocardiograms (EKGs).
“The notion that being in good physical shape portends lower death risk is by no means new,” says lead investigator Dr. Haitham Ahmed, a cardiology fellow at the Johns Hopkins University School of Medicine.
"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.”
To develop the formula, Ahmed and colleagues analyzed data from more than 58,000 heart stress tests in a group patients aged between 18 and 96 in Detroit, Michigan.
The study examined “all-cause mortality” (that is, dying from any cause), which is largely what makes this research so interesting. Theoretically, a person could die in the next 10 years from a freak accident that may not be preventable by being physically fit. But that risk was factored in. And that’s why even test subjects in peak physical shape had a 2 percent chance of dying a decade from now.
But even the authors acknowledge the precise formula may not yet be perfect.
Gordon Blackburn, director of cardiac rehabilitation at the Cleveland Clinic, participants were all patients who had been referred for a cardiac stress test, meaning they likely were already at high risk. The formula still needs to be tested in other groups to make sure it’s as reliable in a general, healthy population.
Despite these limitations, Blackburn was impressed, calling it “a great study," and adding: "The bottom line is fitness or exercise capacity is a strong predictor of mortality.”
But is that risk of death set in stone?
Not according to Blackburn, who says research has shown that you can change your odds of an early exit by changing your fitness level. “It’s a nice catch for patients to know, ‘If I’m going to put this much effort into changing my activity level, what am I going to gain?’ It’s a motivating factor.”
The CDC recommends that adults aged 18-64 get at least two hours and 30 minutes of moderate-intensity aerobic activity, like brisk walking, every week. But Blackburn says only about 20 percent of Americans meet that mark.
So, should you hop on your treadmill and start calculating your death risk at home? No, experts say. The test is designed to be done under a doctor’s supervision and some of the calculations are just too complicated to do on your own.
But logging a few hours on the gym treadmill each week is not a bad idea.