There was a great article in the New York Times recently about a sports scientist who is on a quest to train a runner to complete a marathon in under two hours. Even though the world record right now is just under 2 hours and 3 minutes, a sub two-hour marathon is a bit like the four-minute mile once was—many people think it is impossible (or at least not likely to happen anytime soon). What I appreciated about the article was the way it explained some key concepts in exercise physiology. Since I am preparing to teach my summer Exercise Physiology course in June, I thought this was particularly relevant and worth sharing in my Health & Fitness column in the Aiken Standard this week.
First, let’s put a two-hour marathon in perspective. To do it would require sustaining a running speed of over 13 miles per hour for two hours! Most runners I know would be hard pressed to complete the 285 yards at that pace…forget about the 26 miles that come first. It is also more than twice as fast as the average marathon time of over 4 hours. If you are brave you can see how fast this is yourself by getting on a treadmill and cranking the speed up to 13 miles per hour. Hang on, though, because you won’t last long!
The article mentions the training method known as “live high, train low.” This technique involves athletes spending time at high elevations but doing much of their training at sea level. This works because the key to endurance performances like a marathon is getting as much oxygen as possible to the muscles to use to produce energy. Living at high altitude causes the body to produce more red blood cells, increasing oxygen delivery to the muscles. But because there is less oxygen in the air at altitude, athletes can’t train as hard, which may offset the gains in red blood cells. Because of the lower training intensity, which is essentially doing less work, some athletes realize little benefit from this technique. So, a perfect solution is to live (or spend lots of time) high, but train low to maximize the benefits of both altitude and intense training.
The article also mentions another interesting phenomenon related to oxygen delivery to the muscle. As the heart pumps blood to the muscles it also sends blood returning from the muscles to the lungs to pick up oxygen from the air we breathe. As the red blood cells pass by the air sacs of the lungs (the alveoli), oxygen molecules bind so that the blood is fully saturated with oxygen before it is pumped back to the muscles. But the harder the heart beats during exercise the faster the blood flows. In some elite athletes, the blood flows so fast that the red blood cells don’t have enough time to pick up enough oxygen. This can reduce oxygen delivery to the muscles and impair performance in these athletes. (Fortunately, it isn’t a problem for the rest of us)
Admittedly, I am a bit of a physiology geek, so this is fascinating to me. If you are curious about exercise physiology and sports performance, check out the New York Times article from May 11—it’s a sneak peek into the world of sports science. The article also touches on nutrition, especially carbohydrates, biomechanics, temperature regulation, and training as important factors in reducing marathon times. All of these are topics that I cover in my Exercise Physiology course, too. And in case any of my students are reading this—yes, it will be on the exam!
Nutrition, exercise, and health information can be confusing. But it doesn't have to be that way. What can I help you with? drbrianparr@gmail.com | http://twitter.com/drbrianparr
Dr Parr Says... 