Excess Exercise can Be Bad for the Heart

Exercise is an effective way of reducing weight and lowering risk of several health complications such as diabetes, heart disease and stroke. A new study, however, suggests that excess exercise also, can be bad for health.

The Centers for Disease Control and Prevention (CDC) recommends that people need at least two hours and 30 minutes (150 minutes) moderate intensity physical activity every week and two or more days per week of muscle strengthening exercise.

The research has shown that excess exercise can raise cardiovascular death risk in heart attack survivors.

The study was based on data from 2,400 physically active heart attack survivors. The researchers found that too much of exercise can harm health of people who have suffered a heart attack.

"These analyses provide what is to our knowledge the first data in humans demonstrating a statistically significant increase in cardiovascular risk with the highest levels of exercise," said Paul T. Williams, PhD, of the Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, and Paul D. Thompson, MD.

"Results suggest that the benefits of running or walking do not accrue indefinitely and that above some level, perhaps 30 miles per week of running, there is a significant increase in risk. Competitive running events also appear to increase the risk of an acute event," Williams and Thompson added.

It is important to note that the study was conducted on heart attack survivors and so the results can't be applied to a general population.

In a related study, researchers from Spain conducted a meta-analysis of ten cohort studies that looked into death rates of elite athletes. This study included data from 42,000 top athletes who had participated in different kinds of sports such as football, baseball, track and field and cycling.

"What we found on the evidence available was that elite athletes (mostly men) live longer than the general population, which suggests that the beneficial health effects of exercise, particularly in decreasing cardiovascular disease and cancer risk, are not necessarily confined to moderate doses," comments senior investigator Alejandro Lucia of the European University Madrid, Spain, according to a news release. "More research is needed however, using more homogeneous cohorts and a more proportional representation of both sexes."

The study is published in the published in the journal Mayo Clinic Proceedings.