Is Too Much Exercise Really Bad For You?

There are many supreme athletes who demonstrate to the rest of us exactly how much the human body can endure. It has gotten to the point that the medical community has suggested that pushing your body too hard for too long is not of benefit to either general fitness or longevity. Now, doctors at John Hopkins have carried out a long-term study to refute this finding, stating that the greater your fitness, the longer you may live.

What Have International Studies Shown? 

A Danish study in the Journal of the American College of Cardiology showed that people who pushed their bodies too hard may well undo the benefits of exercise. “Those who ran at a fast pace more than four hours a week for more than three days a week had about the same risk of dying during the study’s 12-year follow up as those who were sedentary and hardly exercised at all. The link held even after the researchers accounted for potentially confounding factors such as age, sex, whether the participants had a history of heart disease or diabetes, or whether they smoked and drank alcohol.”

When is Too Much Exercise Too Much for Your Health?

Other studies from Canada and in medical publications including the Journal of Circulation cited that “while regular exercise reduces cardiovascular risk by a factor of two or three…the vigorous demand of running a competitive marathon increases cardiac risk by seven-fold. Long-distance running also results in high levels of inflammation that may trigger cardiac events and damage the heart post-marathon running.” The “sweet spot” seems to be closer to the “lesser” side of the curve. Study after study has shown that there is a threshold when the benefits of exercise no longer balance with physical well-being. Researchers studying very fit older men (members of the 100 Marathon Club who had run at least 100 marathons) found that half of them suffered some heart muscle scarring, proving that more research may be necessary. Even rats who had healthy hearts at the start of a study of strenuous daily exercise developed scarring and damage by the end. After competitive long-distance endurance events, athletes also showed decreased right ventricle function in their hearts and noticeable scar tissue one week after the race has been run.

The John Hopkins Study

A long-term study of 38,000 patients at John Hopkins University cites that greater fitness equals greater longevity, even at the highest levels of fitness. The researchers do not believe it is accurate to to conclude that all elite athletes are at increased risk of cardiovascular damage, so they attempted to find our when higher fitness levels no longer benefited the subjects’ health. They compared the metabolic equivalents in tests (MET) to see how much stress the body can take before it begins to break down. The upper threshold of their findings was that an estimated exercise capacity of less than 14 METs may well achieve “a continuous, graded reduction in mortality.” Their study of cardiorespiratory fitness testing discovered no upper threshold — in contrast with previous cited studies and articles published in the media — supporting the belief that all patients should engage in regular moderate to vigorous exercise for their health. Researchers admitted to several limitations to their study that warranted further research, while affirming that their data “cautions against any public health message that might dissuade patients from routine vigorous physical activity with the goal of reaching the highest levels of cardiorespiratory fitness.”