Endurance Athletes and Coronary Artery Calcium Buildup
This post is not directed at people who need to start exercising and will read this as an excuse to never start. If that’s you, just don’t read this post.
Rather, this article is directed at type A exercisers and athletes who are religious with their training beyond what is necessary for optimum performance. These are the types who train to train, train to eat more food, train to avoid socializing with others, or train as though it is an equilibrium to balance for a poor diet, which is popular rational yet not evidence based thinking.
Recently, the exercise literature has expanded to try to figure out just how much exercise is good for you, and they found that over 35 miles a week of running or over 150 km a week of cycling was associated with dense plaque build up in the coronary arteries, moreso than the control group of sedentary people.
While this plaque may not be as dangerous as the kind that is found in sedentary folks because it is less likely to break off and cause a clot and associated downstream ischemia of tissues (blood supply being cut off due to a clot), it is alarming and emotional for endurance athletes.
Many endurance athletes got into their sports under the belief that cardiovascular exercise is always healthy. Yes, it is probably very healthy for most people, but when done to extremes, tissue damage may occur.
I say “may occur” because the calcium buildup etiology is not fully understood. Is it from the extra cardiovascular stress from the exercise, the high carbohydrate diet recommended to fuel their performance optimally, or what?
Perhaps endurance athletes at that volume of exercise are chugging sugary beverages like Gatorade to fuel their performance, as recommended by many sports dietitian nutritionists (including me, in some cases). Or perhaps their epithelium is getting damaged from the extra blood flow. We don’t know the mechanism of this damage yet.
All we know is that there is an association found with those who do extreme endurance and coronary artery calcium buildup, which is usually a sign of cardiovascular disease.
Knowing this information, it is too early to give specific recommendations other than to caution individuals who do extreme amounts of exercise to question their purpose in doing so. As much as doing this type of exercise makes you feel immortal, we are still mortal. The body has limits to process calories and to repair damage from exercise (unless you’re Wolverine from X-men and can heal rapidly).
How much exercise is recommended? The Physical Activity Guidelines for Americans 2008 recommends 150 minutes of moderate aerobic exercise or 75 minutes of intense aerobic exercise or a combination of both. Additionally, it is recommended to do resistance training twice a week.
To someone like me, these recommendations are vague. Are we talking hit each muscle group twice a week for resistance training, or are we talking an upper/lower routine, or does it matter? I find the cardiovascular component of this recommendation also excessive for most people who have never exercised before.
For this reason, I think it is important to start where you are at and just focus on fitness parameters that you can measure and improve each time you go. So if you currently don’t walk, try walking. If you already walk, try adding some faster walking or brief running (if you can with your knees).
Again, these recommendations are generic and should always be taken in context of your current health history and consultation with a physician before beginning an exercise program.
For more tailored physical activity recommendations, I’d recommend scheduling a consultation.