How Much Is Too Much Exercise?
When you hear “too much of a good thing,” exercise doesn’t usually come to mind. With approximately 2/3 of American considered overweight or obese, it seems like the more gym time you log, the healthier you’ll be.
We all know that regular exercise can keep you slim, trim, and disease-free, but you can get these beneficial results with just 30-60 minutes a day. For athletes that take their fitness to the extremes, they may be doing more harm than good. A study in the June 2012 edition of Mayo Clinic Proceedings shows that constantly training for endurance events such as Ironman triathlons, marathons, and even long-distance bike rides may damage your heart.
The study authors examined more than 50 different studies on endurance athletes and found a link between extreme training and competing and scarring of the heart, enlargement of the heart and blood vessels, and irregular heart beats. In fact, marathon runners and professional cyclists were five times more likely to have atrial fibrillation, or irregular heart beats.
When you’re exercising at vigorous levels for hours and hours, your heart is pumping a lot of blood, which can cause muscle fibers to tear and inflammation-induced enzymes to increase. As you continue pushing your body to these levels, the damage can cause scar tissue in the heart, possibly leading to cardiovascular complications.
So what’s the optimal amount to run for heart health? According to the study authors, 10-15 miles a week. That seems pretty doable for even the less-than-frequent gym-goer. “What this paper points out is that a lot of people do not understand that the lion’s share of health benefits accrue at a relatively modest level. Extreme exercise is not really conducive to great cardiovascular health. Beyond 30-60 minutes per day, you reach a point of diminishing returns,” says study author James H. O’Keefe, MD, in a video interview.
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