Another warning about endurance training

It’s not clear what defines “vigorous” when it comes to endurance training, but another team of researchers is putting the brakes to working out more than 60 minutes at a time.

On its website, the CBC reports on a scientific review published in the Mayo Clinic Proceedings, which suggests that benefits of vigorous exercise diminish after an hour, and may even cause cardiovascular events. The piece, which quotes author Dr. James O’Keefe from Missouri,  suggests that some endurance athletes could be doing damage to their hearts:

“When people come to me as a cardiologist and say they want to run a marathon I say, ‘OK, do one and cross it off your bucket list and then let’s focus on an exercise pattern that’s more ideal to producing long-term health benefits and improving your longevity,'” O’Keefe said.

People who exercise regularly have lower rates of disability and a life expectancy seven years longer on average than couch potatoes, the researchers noted.

O’Keefe wants people to understand that the lion’s share of benefits come at a relatively modest level. No further benefits are obtained beyond 30 to 60 minutes a day of vigorous activity.

The researchers said elite-level athletes commonly develop abnormal electrocardiograms and their hearts adapt in ways that traditionally weren’t thought to be harmful. Now it seems the cardiac remodelling from excessive exercise can increase their risk of heart rhythm problems like atrial fibrillation.

After people reach their mid-40s, long and intense exercise can cause scarring and fibrosis in the heart, O’Keefe said.”

The ultra running world took notice this winter when Micah True died while running a 12-miler.  The author of Born to Run , known as the Caballo Blanco, died when the rhythm of his heart went of control. He would sometimes run a 100-miles a day,  and some people blame running for his death at age 58.

His is an extreme case, but combined with the perception of increasing number of deaths at marathons, people want to know more about what could be “excessive” when it comes to endurance training and the heart.

Time to reconsider contact sports at young ages?

With the number of studies on concussion in sport multiplying, more and more focus is now being placed on what’s happening to kids in contact sport. Do you think we need to re-think how we organise youth sport?

The New York Times recently carried a piece on how girls and younger children are more susceptible than others to severe effects of a concussion. Here’s an excerpt from the piece:

“Researchers say that younger athletes may be at greater risk of damage from concussion because their brains are not fully developed. There is also some evidence that young women may suffer more symptoms than young men because of higher estrogen levels, which may exacerbate brain injury, as well as greater rates of blood flow and higher metabolic needs in the brain, which may make symptoms more pronounced. But, says Mark Hyman, author of “Until It Hurts: America’s Obsession With Youth Sports and How It Harms Our Kids” (Beacon Press, 2009), girls may also just be more willing than boys to admit to injury and seek treatment.

“We don’t expect girls to be indestructible, as we do boys,” who may be more likely to play through pain to avoid being sidelined in their sport, he said. “Attitudes are changing about that. But not fast enough.”

The findings also highlight the dangers of treating children and teenagers as “miniature adults,” he added. “The brain and head of a small child are disproportionately large for the rest of the body,” he said. “The result is that their heads are not as steady on their shoulders. When they take a big hit in a football game or are slammed with an elbow in a soccer game, their brains move inside their skulls. That’s when concussions occur.”

My daughter plays on her high school rugby team here in Montreal, and one of her teammates suffered a serious concussion in the second game of the season. Her headaches have been so bad that she missed a month of school after suffering the injury. I noticed that there are no weight limits in their  league, which results in some serious mismatches on the field. In boy’s (american) football, limits on weight variations are respected at the developmental stage.

In Canada, the majority of discussions about concussions have been focussed on the NHL (see Sidney Crosby)  and minor hockey. With science telling us more about what’s happening in the noodle up there, it’s time to give more thought about other contact sports.