When it comes to exercise, it's likely most of us aren't getting enough. But working out too much could also pose problems, which begs the question whether there should be an upper limit for physical activity.
Paul Williams, a staff scientist at Lawrence Berkeley National Laboratory, wanted to find out how beneficial exercise is for the heart and therefore decided to research when effects wane or even become harmful. The report published in Mayo Clinic Proceedings sheds some light on the matter.
Don't go overboard in the gym! © Cover Media
Heart-attack survivors enrolled in either the National Runners’ Health Study or the national Walkers’ Health Study were used for the data. The two studies hoped to find what effect varied amounts of exercise have on deaths due to heart disease.
From the results, it appeared exercise in high doses can do more harm than good. Those who had previously suffered a heart attack and spent either six hours a week working our vigorously or more than 30 miles running increased the risk of death due to cardiac problems by up to twice.
“I certainly expected a point of diminishing return, but I wasn’t expecting to see the increase in mortality,” William said.
Moderate exercise however had a positive impact. People who worked out more than the recommended minimum but not as much as the extremely active group lowered their risk of dying of heart-related causes by 63 percent, compared to those who partook in very little physical activity.
“I would say the gains of being active are substantial, but up to a certain point," Williams concluded.
Right now, the data only applies to people who have suffered from heart disease in the past. However, Williams is working on results for the general population. This means exercise could be "prescribed" in "doses" to combat diseases linked to low physical activity.
For now, he advises heart-attack survivors "more is better - up to a point". © Cover Media