Thousands of people raced to the finish line of the Rock ‘n’ Roll Marathon on Sunday morning – some after training for months to complete the half and full marathon.
But is this healthy endeavor actually doing more harm than good? After all, the Greek messenger the marathon was modeled after died at the end of his 26.2-mile journey.
A study released by the Mayo Clinic Proceedings on Monday found that extreme exercise could possibly damage the heart, causing it to scar.
“A routine of daily physical activity can be highly effective for prevention and treatment of many diseases, including coronary heart disease, hypertension, heart failure and obesity,” said co-author of the study Dr. James O’Keefe in a statement. http://www.youtube.com/watch?v=jp_zviTtIQk
"However, as with any pharmacologic agent, a safe upper dose limit potentially exists, beyond which the adverse effects of physical exercise, such as musculoskeletal trauma and cardiovascular stress, may outweigh its benefits."
Meaning excessive endurance exercise, such as running marathons or ultra-marathons, over a long period of time could lead to heart problems.
“A lot of people misunderstand that more is better,” O’Keefe said. “It’s is not really conducive to long-term cardiovascular health.”
The study found that exercising vigorously beyond 30 to 60 minutes a day can often yield diminishing returns. Because of the potential risk, he doesn’t recommend people run marathons or ultra-marathons – especially people older than 40.
“This is not a healthy, long-term exercise pattern,” O’Keefe said. “It’s just too much exercise.”
He recommended runners should limit their distance between 2 and 4 miles per workout, which goes against the philosophy of the millions of runners who participate in long-distance events.
“I think he put the limit a little too low,” said Dr. Lori Daniels, an associate professor at the UC San Diego Cardiovascular Center.
O’Keefe and Daniels both stressed the importance of exercise -- it does lead to a longer life in most cases -- but differed on the amount.
“Overall, we know that exercise does more good than harm, we know it improves cardiovascular function overall,” Daniels said.
Even though there is a slight threat for a heart attack post-workout, Daniels said that people who exercise on a regular basis are less likely to suffer a heart attack.
What about the most extreme of the events? Competitions such as ultra-marathons and Iron Man have been criticized for being too harsh, but Daniels said she would not discourage people from striving for their goals. Still, she recommends runners should get screened before participating in extreme athletic competitions such as Iron Man.
“I don’t think the human body was designed to do that,” she said. “But I would never tell a patient not to do one of those events.”
San Diego running coach and author of “Running a Marathon for Dummies” Dr. Jason Karp said over a long period of time, extreme competitions could be harmful. But he was also surprised to hear the findings of the Mayo Clinic study.
“There’s a mountain of evidence shows that running is one of the best things you can do for your body,” Karp said.
The key to being safe when training for an event like a marathon or triathlon is patience. Karp said while most people give themselves a few months to train for the 26.2-mile event, they really should give themselves more time.
“They really need to give themselves a whole year,” he said. “But nobody has that kind of patience; we all want that instant gratification.”
Running groups that coach people for long-distance running events, such as Team in Training, boast a 4 to 5 month plan that gets people racing in less than half a year.
Karp said in many cases, athletes who train for a shorter period of time end up putting stress on their joints and heart simply because they view the marathon as a holy grail.
“If people do it in a safe way, most of those people who did the [Rock ‘N’ Roll Marathon] race yesterday were not adequately prepared and it’s a very big stress for them,” he said.
As long as people are safe about their running habits, the majority of evidence suggests that it is very good for your heart and it’s an effective way to lose weight. Karp encourages people to take their time and take the study results with a grain of salt.
“I think the important point to make is that these findings pertain only to extreme exercise,” Karp said, “which only includes a few people relative to how many millions of people run.”