Tuesday, February 03, 2009
My friend and fellow distance runner Matthew Kerr sent me a very interesting article from CNN yesterday which I think makes for an excellent discussion. In it, author Madison Park describes the high rates of obesity and associated health risk among retired NFL linemen (for those not familiar with football, the linemen are the massive men who line up and drive against each other on each play). While they are actively competing, these men strive to be as large as possible so that they are more effective in pushing opposing players. However, the same eating habits that allow them to put on massive amounts of weight as a player can lead to devastating chronic disease risk once their playing days are over.
While interesting, this increase in metabolic risk in former athletes is not unheard of - in fact a similar phenomenon has been observed in Japanese sumo wrestlers. Although sumo wrestlers are known for their large size, they are also extremely physically active, and are characterized by low levels of visceral fat, which is the particularly hazardous fat which accumulates behind the abdominal wall (for a paper by Dr Jen Kuk examining the association of visceral fat and mortality risk, click here). These active wrestlers serve as an excellent example of the positive influence of physical activity on health regardless of body size. In contrast, once sumo wrestlers are no longer competing their levels of physical activity drop dramatically, and we see a large increase in their risk of chronic disease, likely related to an increase in visceral fat levels.
When I first read the article on CNN I actually became a little worried about my own future health - I competed for 5 years as a collegiate distance runner both at the University of Calgary (go Dinos!) and here at Queen's (go Gaels!) and am currently training for the Boston Marathon later this spring. Suffice it to say that with all this running, I do a lot of eating - sometimes it seems that we distance runners do little other than run and eat. So, like the football players and sumo wrestlers, I am accustomed to taking in massive amounts of calories on a daily basis - am I too destined to a life of increasing visceral fat and health risk once my competitive days are over? Luckily, the answer to that question is no (or at least probably not).
Although their physical activity levels are likely to have dropped since college, individuals who were varsity athletes are more likely to be active in middle-age than their peers who were not varsity athletes (for a great review on this topic by Bob Malina, click here). Given the strong associations between physical activity and reduced health risk, it is not surpising then that individuals who were varsity athletes in college may still have reduced health risk later in life, mainly due to the fact that they are more physically active than their peers who were not varsity athletes.
So why do NFL linemen and sumo wrestlers have so much risk that other athletes seem to avoid? Most athletes eat roughly as much food as they need - my appetite and drive to eat increase dramatically with my training load, and drop just as quickly when I take time away from training in the off-season. It is in my best interest to eat as much as my body needs, because too much or too little food will both take away from my performance. If I reduce my physical activity after my racing days are over, I will be much less hungry, and my caloric intake will drop dramatically. However, football linemen and sumo wrestlers are consciously trying to eat more than their bodies need so that they can put on weight. While they are competing, they are learning to ignore the signals that tell them that it is time to stop eating. Once they are done competing, they need to unlearn these habits, in order to avoid excess weight gain.
Thanks to Matthew for passing along the article.
Enjoyed this story? Share it with your friends by clicking the buttons below!
To get future posts delivered directly to your email inbox or to your RSS reader, be sure to subscribe to Obesity Panacea.