Ever wanted to know how long you have left to live? Well, you could find out on your next workout.
At least that's the claim being made by cardiologists at Johns Hopkins University School of Medicine, who say they've developed a formula to estimate your risk of dying over the next decade, based on your ability to run on a treadmill.
The research, based on data from 58,000 heart stress tests and published this weke in the journal Mayo Clinic Proceedings, has helped the team create a new algorithm called the Fit Treadmill Score.
Lead investigator Haitham Ahmed described it as “an elegantly simple equation that requires no additional fancy testing”.
While those with abnormal readings in usual stress tests will be referred for further examination, people with normal results are generally left to their own devices. But this new research suggests that varying degrees of fitness can “reveal telling clues” about cardiac and respiratory health, and “therefore, overall death risk over time”.
“Stress test results are currently interpreted as ‘either/or’ but we know that heart disease is a spectrum disorder,” Ahmed says. “We believe that our FIT score reflects the complex nature of cardiovascular health and can offer important insights to both clinicians and patients.”
As well as age and gender, the formula considers peak heart rate reached during intense exercise, and how much physical exertion your body is able to tolerate based on metabolic equivalents (METs).
Senior study author Michael Blaha said the score was “easy to calculate and costs nothing beyond the cost of the treadmill test itself”.
He added: “We hope the score will become a mainstay in cardiologists and primary clinicians’ offices as a meaningful way to illustrate risk among those who undergo cardiac stress testing and propel people with poor results to become more physically active.”
Research suggested fitness was the “single most powerful predictor of death and survival” - more important than diabetes and family history of premature death – which underscores the profound importance of heart and lung fitness, the investigators say.
Participants were given scores between negative 200 and positive 200. Those with 100 or more had a two per cent risk of dying in the next decade, while those with scores between zero and 100 had a 3 per cent risk.
People with scores between negative 100 and 0 had an 11 per cent risk of dying in the next 10 years, while those with scores lower than negative 100 had a 38 per cent risk of dying.
Published along with the study is a chart depicting death risk by age, gender and fitness level, which can be printed on placards for use in physician’s offices to guide clinical advice.
For example, a 45-year-old woman with a fitness score in the bottom fifth percentile is estimated to have a 38 per cent risk of dying over the next decade, compared with two per cent for a 45-year-old woman with a top fitness score.
"We hope that illustrating risk that way could become a catalyst for patients to increase exercise and improve cardiovascular fitness," said Blaha.