Number of words – 793<\/p>\n\n\n\n
You hit the fast food drive-through a couple times a week, and your grocery cart is regularly filled with cookies, packaged doughnuts, ice cream, chips (and dip). But you\u2019re thin. You run\u2014a lot\u2014and you\u2019re not gaining any weight, so all\u2019s good, right? Well, not exactly. Put down the chocolate cupcake and hear us out.<\/p>\n\n\n\n
While runners do tend to be much healthier than the general population, with lower rates of diabetes and heart disease, that\u2019s largely due to a healthy diet rather than running regularly, says Sara Mahoney, Ph.D., chair of the department of exercise science at Bellarmine University. In general, because runners run, they take care of their bodies by also eating well and resting.<\/p>\n\n\n\n
But not all of them. Some of them\u2014and we all know one\u2014subsist on doughnuts and burgers. In the short term, running can mitigate the negative health effects of that lifestyle. But over decades, exercise loses its protective abilities.<\/p>\n\n\n\n
Longtime Boston Marathon director Dave McGillivray, 63, learned this the hard way. McGillivray, who\u2019s run the Boston course every year since 1973, logged 90 to 120 miles a week in his heyday, and every year on his birthday he runs his age in miles.<\/p>\n\n\n\n
Four years ago, however, McGillivray began feeling short of breath at the start of workouts. An angiogram revealed he had severe coronary artery disease. \u201cWait a minute,\u201d McGillivray said. \u201cI\u2019ve been running all my life. I\u2019ve done eight Ironman Triathlons and 140 marathons. I\u2019ve run across the United States. How can I have blocked arteries?\u201d<\/p>\n\n\n\n
McGillivray has a family history of chronic cardiac illness, and he had also been eating like a teenager for most of his life. \u201cAs a runner, I just felt that if the furnace was hot enough, it would burn whatever you put in,\u201d he says. \u201cSo I would eat anything and everything I wanted.\u201d<\/p>\n\n\n\n
That attitude is not uncommon among runners. Half of the Runner\u2019s World Twitter followers who responded to a poll said they eat whatever they want because they run and don\u2019t gain weight. Those numbers align with a recent survey of recreational ultrarunners, which found that 62 percent do not follow the American College of Sports Medicine\u2019s recommendations for nutrition, despite being aware of them.<\/p>\n\n\n\n
But just because the number on the scale seems healthy doesn\u2019t mean your diet isn\u2019t doing damage on the inside. \u201cTime and time again, I meet runners in their 50s and 60s, who think they\u2019ve done pretty much everything right in their life from a health perspective, who end up with heart disease. When I talk to them about their diets, they are often quite shocking,\u201d says McGillivray\u2019s physician, Aaron Baggish, M.D., director of the Cardiovascular Performance Program at Massachusetts General Hospital Heart Center and associate professor of medicine at Harvard Medical School.<\/p>\n\n\n\n
While diet is one of the most important components of health among athletes, it is also one of the least understood, due to lack of clinical trials, says Baggish. Still, he points to overindulgence in simple sugars as \u201cthe single most common dietary transgression among any endurance athletes, but specifically runners.\u201d He\u2019s calling out white bread, white pasta, white rice, and refined sugars. \u201cEat large portions of these, and the body turns them into bad molecules, bad types of fat, bad oxidative sugar species\u2014things that do a lot of damage to the heart vessels,\u201d Baggish explains.<\/p>\n\n\n\n
Still, runners often hear mixed messages about how exercise\u2014particularly high-intensity sessions\u2014can erase the ills of a junk-food habit. A recent study by Christian Duval, Ph.D., a researcher in the department of exercise science at the Universit\u00e9 du Qu\u00e9bec \u00e0 Montr\u00e9al, provides the case in point: Duval fed a small group of men between the ages of 18 and 30 breakfast sandwiches, burgers, fries, dessert, and soft drinks for every meal of the day for two weeks. The subjects ate nary a vegetable, and they were consuming \u201can enormous amount of saturated fat, a very large amount of sugar, which is even worse than fat, and chemicals found in processed food,\u201d says Duval. But thanks to an additional prescription of interval training, Duval\u2019s subjects didn\u2019t gain weight. What\u2019s more, when he tested their blood for fat buildup and inflammatory processes\u2014main drivers of heart disease, cancer, and other chronic diseases\u2014it didn\u2019t seem like the diet had any effect.<\/p>\n\n\n\n
But this study, which was widely reported, was over the course of weeks, not years. The damage from a bad diet can take far longer to register. Take atherosclerosis, a disease that Baggish says festers over many years. \u201cIt\u2019s a process that starts when we\u2019re young, and it gradually accelerates over time. People don\u2019t feel symptoms until the disease is already quite pronounced and progressed.\u201d<\/p>\n\n\n\n