A marathon, or any event for that matter, can be very stressful to the human body without proper preparation, and especially if unhealthy diet, training, and lifestyle factors are too much for the body to bear. High-caliber long-distance athletes and sports icons have died, perhaps as a result of their running and other factors.
Jim Fixx, the author of the 1977 bestselling book, The Complete Book of Running, died of a heart attack at the age of 52. Fixx is credited with popularizing the sport of running and demonstrating the health benefits of regular jogging. His autopsy revealed that atherosclerosis had blocked three of his coronary arteries by 70% or more. This led many to believe that running was not as beneficial as once thought. However, Fixx was genetically predisposed (his father died of a heart attack at age 43, and Fixx himself had a congenitally enlarged heart), and had several lifestyle issues: he had a stressful occupation, had just gone through a second divorce, and was overweight and a smoker before he began running.
Ryan Shay was an American professional long-distance runner who collapsed five miles into the 2007 Olympic marathon trials. He died of a heart attack due to a preexisting cardiomegaly (enlarged heart).
This is not as uncommon as you may think in distance athletes. A good friend of my brother’s growing up died of a sudden heart attack while out on a training run with his fellow cross-country team. He was only 24 and a national-level runner. Steve Larsen, the professional mountain biker, road biker, and triathlete who won Ironman USA in 2001, died suddenly in 2009 at age 39. In March 2012, the famous ultrarunner Micah True, aka “Caballo Blanco,” died of cardiac arrest while on a training run.
A January 2012 study in the New England Journal of Medicine looked at the incidence and outcomes of cardiac arrest. (Cardiac arrest is when the body doesn’t efficiently pump blood due to poor heart contractions, whereas a heart attack is a lack of blood flow to the actual heart muscle.) The study found that atherosclerotic coronary disease and hypertrophic cardiomegaly accounted for the majority of cardiac arrests, and the incidence rate was significantly higher during marathons and in men than in women. The atherosclerotic coronary disease does not result in the traditional plaque rupture leading to an embolism (blockage in a blood vessel), but ischemia—a lack of oxygen that is unable to meet the demand the body requires.
In December 2011, an article published in the European Heart Journal found that marathon runners and others engaging in extreme endurance exercise may temporarily damage the right ventricle of their heart. This was reversed one week later in most of the 40 athletes they studied, but five of them showed lasting damage.
These damaging cardiovascular effects of long, hard training and racing are in-line with what many long-distance athletes put on their bodies. Athletes are taxing their cardiovascular systems throughout a distance event, much like a chronic high-intensity interval session over a very long period with inadequate recovery. And everybody has to sprint to the finish—even if they’re last. If you’re training aerobically and have built a sufficient aerobic base, then you’ll be racing primarily aerobically and be able to withstand anaerobic periods during the race. The chance of any ischemic incidence is greatly reduced, perhaps eliminated, in such a conditioned athlete.
Based on the groups of people I associate with and the types of patients I see in my office, I think the boom of half and full marathon racing is creating more and more unhealthy people. Too many people should not be doing these events—they’re not even healthy enough for a 10K. I say healthy, not fit, as they have the fitness to stick out the miles, but their health suffers because their lives and training are too anaerobic. Interestingly, those doing ultras and Ironman distance triathlons seem to be healthier, and my thought there is that it is due to them training much more aerobically since these events can last in the 10–20-hour range, if not longer. There are, of course, still a lot of unhealthy long-distance triathletes and ultra runners, but from my experience, it’s the people who want an obtainable goal and sign up for a half or full marathon that end up injuring themselves and decreasing their overall health.
Perhaps those who put the stickers “13.1” or “26.2” on the back of their vehicles to say they went the distance should also include their heart rate, maybe their time too—but heart rate is more important. It’s much more respectful to the body for a 40-year-old to run a marathon in four hours at a 140–150 HR than to do the same race in three and a half hours at a 155–165 HR. A marathon run by a Kenyan in two hours is often going to be much less stressful on his body than someone “running” a four- to six-hour marathon.
Extreme racing and training can take a toll on an athlete’s body, even for a highly fit individual. But this doesn’t mean that aerobic conditioning is bad, as discussed in Part I. Dietary and lifestyle factors play a huge role here. Inflammation is one main factor that will raise your risk of not just performing poorly, but perhaps dying from working out or racing. Inflammation of the body can be measured with a blood test to test for C-reactive protein (CRP). CRP levels increase dramatically in acute inflammation and remain high when there is chronic inflammation. Elevated CRP levels are associated with diabetes, hypertension, and cardiovascular diseases. Inflammation is often dramatically increased following a marathon. Although the inflammation may subside in many, if there are several other health factors involved, then the athlete could be in a chronic state of inflammation. A healthy CRP level should be <1.0 mg/L, although “normal” is allowed up to 3.0 mg/L. I’ve raced 20 Ironman races and check my CRP at least once a year. It is always well below 1.0 mg/L, often <0.5 mg/L.
If you keep it aerobic the majority of the time, running long distance can be very beneficial to your overall health and longevity.
In 2010, researchers from the University of Nevada, Las Vegas, published a review of 14 studies comparing the longevity and mortality in elite athletes with that of the general population. Included in these studies were data for endurance athletes, power athletes, and mixed-sport athletes. They concluded that elite endurance (aerobic) athletes and mixed-sports (aerobic and anaerobic) athletes survive longer than the general population, as indicated by lower mortality and higher longevity. The studies of power (anaerobic only) athletes were inconsistent.
Long-distance runners and cross-country skiers lived significantly longer than the general population (2.8–5.7 years longer). Soccer, ice hockey, and basketball players, track and field jumpers, short- and middle-distance runners, and hurdlers also survived longer than the general population (four years longer).
Though the studies looked at elite athletes and not the average Joe running marathons or playing a hard weekend soccer game, it does provide merit that aerobic activity is very beneficial to the body—but it has to be true aerobic exercise. Anaerobic exercise combined with aerobic exercise is beneficial, too, but only when a sufficient aerobic base has been built (Part II). It’s most likely safe to say these types of elite athletes have a superior aerobic base.
Keeping inflammation at bay is highly dependent on diet. Zero partially hydrogenated oils and as few refined vegetable oils (corn, soy, safflower, sunflower, canola, peanut) as possible are important steps in keeping inflammation down. Good fats from extra virgin olive oil, fish oil, coconut oil/milk, eggs, and avocados are also vital, as is a diet low in refined sugars and carbohydrates. (Think the paleo diet.) Obviously, most long-distance athletes are carb junkies. They drink sugary fluid-replacement drinks and consume gel packs often, usually daily. Due to improper training (lack of an adequate aerobic base), they’re burning predominantly sugar when training rather than fat, and so they must consume more and more sugar to fuel this cycle. This all provokes and sustains inflammation and makes their tissues insulin resistant rather than insulin sensitive. Insulin resistance is very, very bad. How long can you train without food or some sugar water before having blood-sugar handling problems such as cramping, lightheadedness, or even bonking? If it’s less than one hour, then you’re very anaerobic. Aerobically conditioned athletes won’t break down and bonk or hit the wall as the miles add up.
Some note that a general guideline for a well-conditioned aerobic athlete can be seen in their race times over various distances. Generally, for example, if your one-mile run is at 7:00, then your 5K race time should be around 22:30 (7:15/mile), your 10K time around 46:30 (7:30/mile), your half-marathon 1:41:30 (7:45/mile), and your marathon around 3:30:30 (8:00/mile). Though genetics play some role here, if you’re running your 5K at 23 minutes and your marathon time is around four hours (or more), you’re not aerobically conditioned to run so far. You’re running the race too anaerobically (inefficiently), period.
As discussed in Part II, the more you develop your aerobic system, the more you develop your mitochondria. The more mitochondria you have, the less lactate your body makes at a given intensity. This raises your lactate threshold, so what was once mostly anaerobic is now less (and more aerobic). The net result? You’re faster, more efficient, and much healthier.
Developing the aerobic system is important. Actually, it’s vital. There is no shortcut to it. It takes consistency and discipline in training. Consistency means you have to stick with it and give it time. If you’ve never developed your aerobic base, it could take several months, maybe a year. Follow the aerobic and anaerobic training guidelines to know when you should add in some anaerobic training and/or weights. The discipline is not just to stick with it, but to keep yourself from going too hard. A heart rate monitor becomes very important with aerobic training, and you may not be able to train with your friends unless they want to go at your pace. Running long and hard too often, just like many people training for a half or full marathon, can definitely kill you, but so can a life of no running or little movement. Slow down and take the time to develop superior fitness and health.