It’s intuitive that being out of shape increases the risk of a heart attack and exercise decreases this risk. However I also think many of us wonder about how much is too much. I have been practicing preventive cardiology for 20 years and, being based in Boulder, CO have had the privilege of seeing a large number of elite masters age athletes in my practice. In this blog post I would like to talk about why extreme endurance exercisers (mainly runners) can have more arterial plaque and whether or not this increases the risk of a heart attack.¹ I say mainly runners because we have the most data on them compared to cyclists, rowers or cross-country skiers. Many of us in the field of cardiology have been trying to figure out why some athletes get plaque and if this increases the risk of heart attack. Exercise is supposed to be good for you but does extreme exercise increase risk and at what level? Too little physical activity is the problem for the majority of Americans, however in the last 10 years there have been increased reports of increased arterial plaque in experienced male endurance athletes. Women are not typically studied...