Being fit can protect you from heart disease even after suffering one attack, according to new research.
The study found evidence that higher levels of physical fitness may not only reduce the risk of heart attacks and death from all causes, but also possibly improve the chances of survival after a first attack.
The findings, published online by the journal Mayo Clinic Proceedings, were based on medical records data gathered from more than 2,000 men and women.
Doctor Michael Blaha, assistant professor of medicine at the Johns Hopkins University School of Medicine in the US, said: “We knew that fitter people generally live longer, but we now have evidence linking fitness to survival after a first heart attack.
“It makes sense, but we believe this is the first time there is documentation of that association.”
Doctor Clinton Brawner, clinical exercise physiologist at Henry Ford Health System, said: “Our data suggest that doctors working with patients who have cardiovascular risk factors should be saying, ‘Mr. Jones, you need to start an exercise programme now to improve your fitness and chances of survival, should you experience a heart attack.'”
For the new study, the researchers focused on medical records of people who had taken a treadmill stress test before their first heart attack and used the patient’s achieved metabolic equivalent score (MET) as a quick, although not perfect, measure of energy consumption at rest and during physical activity.
The higher the MET score, the more physically fit the participants were considered to be.
MET scores range from one to 12, where one is considered the equivalent of sitting on the couch, three aligns with walking, seven with jogging, 10 with jumping rope and 12 with sprinting.
The researchers found that overall, the 634 people achieving MET scores of 10 or higher had about 40 per cent fewer deaths after a first heart attack as compared to the rest of the patients.
They also observed that a third of the 754 patients with a MET score of six or less died within a year of their first heart attack.
Overall, their results showed an eight per cent reduction in death risk for each whole-number increase in MET score after a first heart attack.
Dr Blaha emphasised that fitter patients still had heart attacks but appeared less likely to die from them.
From an initial pool of 69,885, the researchers excluded patients who had heart attacks before the stress test, patients that never had a heart attack or patients whose records were missing fitness data from the stress test, narrowing the final research pool to 2,061 people.
The patients were an average of 62, 38 per cent were female.
Dr Blaha said they didn’t determine if people who are fitter have less damaging heart attacks, or if they have same-sized heart attacks as those who are unfit but survive them better.
Decades of research show that cardiovascular fitness does increase blood flow to the heart and may aid in healing, which is a likely contributing factor to lower mortality rates.
In a 2013 study, Blaha and his colleagues at Henry Ford Hospital linked physical fitness to improved overall survival and heart attack prevention in people with already established coronary artery disease, including a previous heart attack.