CHARLOTTE -- You probably know someone who's had a treadmill stress test to determine the strength of the heart. Now researchers say they can use that information to tell even more about our health.

Researchers say they've developed a formula that can estimate an individual's risk of dying.

Right now, treadmill tests are really only for people with established heart disease or signs of heart trouble. The new test, called the Fit Treadmill Score, can be used for anyone.

The treadmill score doesn't break new ground. Most know that being in good physical shape is better for your health. What the test does provide is an easy equation that doesn't cost any more than a cardiac treadmill test.

This was a big study involving more than 58,000 people ages 18 to 96.

Among people of the same age and gender, fitness level was the single most powerful predictor of death and survival even after accounting for variables, conditions like diabetes and family health history.

For example, a 45-year-old woman with a very low fitness score is estimated to have a 38 percent risk of dying over the next decade compared to a 2 percent risk for a 45-year-old woman with a top fitness score.

One thing doctors like about this study is that it's very simple and it's simple to replicate. The fit score can be applied to anyone at any age.

Your doctor will need a standard heart stress test and will measure in other factors including how well you tolerate physical exertion.

It's good motivation to get moving.