We all know that exercising is good for the body and the mind, but is there a limit to how beneficial too much exercise may be?Exercise and good health go hand in hand. Exercise and physical activity have been linked to protection against heart attack, stroke, diabetes, some types of cancer, dementia, and more. A little bit of exercise is better than none, and more than a little is even better.
If I push myself more and more, run further and further are the results for the body’s health better and better or do the benefits taper off at a certain point? For example, walking an hour a day is great for you but is walking three hours a day even better for you or does it make no difference? What about running? Does running 100 kilometers a week do more for your heart and body than running 50 kilometers a week?
Over the years, hundreds of studies have shown that exercise and physical activity are associated with lower rates of heart disease and longer life. We think this is due to exercise itself. But none of these studies has ever been able to exclude the possibility that people who choose to exercise are genetically and physiologically hardier. That might be especially true for endurance and elite athletes.
In the JACC article, we explored four recent studies that suggest exercising a lot may not be as good for the heart or long-term health as exercising more moderately. In these studies, people who exercised strenuously appeared to lose most of the cardiovascular benefits that exercise provided to more moderate exercisers.
It’s important to keep in mind that the number of people at the upper end of the exercise spectrum in these studies was very small. So the results should be used to generate new hypotheses, not to make recommendations about exercise. Unfortunately, the media attention these studies generated has sown some confusion among the public about the benefits — and hazards — of exercise for preventing heart disease.read more