We have known for some time that physically active individuals have a longer life span and are overall healthier than those who are sedentary.  This certainly extends to heart disease, where exercise clearly has a beneficial effect for both prevention and therapy. But more recent research into “extreme” levels of exercise, especially endurance running, is raising questions about whether it is possible to exercise too much. This is becoming a controversial and heavily debated topic in the world of sports medicine.

Recently, a new study was released which adds important information to this debate. This was a very detailed study in Europe of individuals over many years to try to link the degree of jogging with overall mortality and cardiovascular health.  Called the Copenhagen Heart Study, this particular analysis identified over 1000 active joggers and followed them for over 12 years. Not surprisingly, those who exercise either mild or moderate amounts were healthier and lived longer than their sedentary counterparts. What was most interesting however, is that those who ran the most vigorously (defined as 4 or more sessions weekly, or high intensity sessions) actually did not have improved survival compared to the sedentary non-runners.  This suggests that perhaps more extreme levels of running may actually be harmful. In fact, other studies have suggested a similar connection, such as a higher risk of irregular heart rhythms in those who participate in extreme sports.  The study did have some limitations as it did not address other types of exercise, the participants were not randomized,  and the limited number of participants prevented detailed analysis and comparisons.

So, for overall wellness and heart health, what level of exercise should we recommend? Here are some guidelines:

1. Remember, always check with your physician or other health provider to determine whether physical activity is appropriate for your specific medical condition.

2. This study adds to the evidence that light and moderate exercise is clearly beneficial.  The current recommendation by the American Heart Association is 150 minutes a week of moderate exercise. That could include brisk walking, light or moderate jogging, or many other types of aerobic activity. However, as we previously reported, even very short sessions of exercise can be beneficial.

3. High-intensity exercise, defined as 4 or more sessions a week, or frequent sessions of very high intensity activity (for example, running > 7 MPH) , may not be optimal for long-term health and survival. There is still minimal evidence that this level of exercise is actually harmful, but the benefit may not be as high as for those that stick to moderate exercise.

4. For those who elect to perform higher intensity exercise, it may be reasonable to cycle the periods of high activity with “down time”or cross-training with other less-intense types of exercise. There is still really no evidence that any particular type of aerobic exercise is best, so an active lifestyle that focuses on a mix of activities may be optimal.

Other than perhaps diet, an active lifestyle is still the single most effective way to prolong our lives and prevent disease. We hope you will join the HeartHealth Docs in participating in the upcoming Capital City Half Marathon and the New Albany Walking Classic.

Here is a reference to the study mentioned and this article.

Here is our overview of exercise, and an additional article on the benefits of exercise.