The endurance event equation

Why some athletes can run hundreds of marathons in a single year

For some, completing just one marathon is bucket list material. But then there are folks like world record holder Larry Macon, who claims to have completed more than 1,900 of those 26.2-mile slogs since 1996 including 255 in a single year. And legends like Ed Whitlock, who ran his first marathon in his 40s, raced to two sub-three-hour finishes in his 70s (the first and only man to do so, even once), and continued to smash age group records until his death at age 86 (mere months after a sub-four-hour finish). Pro favoriteMeb Keflezighi, 42, says he’ll be hanging up his competitive running shoesafter the NYC Marathon this November, his 26th elite race in 25 years. And of course, there are plenty of above-average Joes in the 100 club (as of July 1, 2017, 568 athletes are in the 100 Marathon Club of North America) or who complete the 50 in 50 which is a marathon in every state (there are 1,289 finisher-members of the 50 States Marathon Cluband 4,271 members who have finished at least 10 marathons/states).

How many is too many

All of this begs the question: How many marathons—or other hard endurance events, like triathlons—can the body actually handle? Of course, there’s no specific number that applies to every athlete. “I don’t think anyone from the scientific field or professional coach has the definitive answer to the question because it is so dependent on the individual, their approaches to training and racing, and their health history,” says Gary Berard, a certified running coach based in NYC and founder of GB Running. “We are individual athletes and, as such, respond to stresses independently from one another.”

Adds Janet Hamilton, certified running coach, exercise physiologist, and head coach of Atlanta’sRunning Strong: “There are so many instances of people having run 100 or more and are still enjoying it and having a blast. And then some say, ‘this sucks, I’m done after one.’” Any number of reasons can separate those two, from a love (or lack thereof) of the act of running itself to the scope of one's personal bucket list to a genetic physiological predisposition to be able to handle endurance (from aerobic capacity to percent of slow-twitch muscles to bone and tendon density).

How to keep going and going

What both coaches also agree on, if your aim is to keep running many marathons or other hard-on-the-body endurance events, is the importance of how you plan your racing and training schedule. Both cite the no-more-than-two-marathons-a-year (or three in two years) guideline—which most elites follow, too—as a good start, allowing 20 weeks of training for each with a four-week recovery cycle between. Still, that might be too much for many people, resulting in injury and even just life getting in the way. After all, marathon training (or any type of endurance training) can be like having a second part-time job. Hamilton also cautions about becoming too cavalier as your race numbers climb. “You have to respect the distance,” she says. “Even if you’ve done 10, the 11th is just as long as the first was.”

If you do aim to pound more pavement than that, Hamilton says you have to go in with the right expectations. "Not every race will be a PR," she says. For example, she has one client whom she describes as "fairly durable and not injury-prone" who signs up for many races of various distances, including five or six marathons a year. "Suffice it to say that she never seems to perform up to what she's capable of because she's basically running these events with no taper and no recovery, using them as training runs." If you hope to join the ranks of these marathon collectors, you have to tick the boxes of picking your races wisely, training with focus, building in recovery time, addressing issues quickly, and generally respecting your body.

How to know when enough is enough

Most athletes are aware of the signs of overtraining—a general dread or lack of interest in sessions, fatigue that doesn’t shake, poor sleep, etc.—but some ignore them until things get worse. And endurance athletes, by nature, can be pretty good at brushing off discomfort and even pain; after all, racing 26.2 miles doesn’t feel good to anyone. “Marathons are grueling on the body, regardless of an athlete’s finishing time,” Berard says. “Nearly every physiological system is strained during a marathon: muscles, tendons, and hormones are pushed to the limit.”

The same goes for the training cycle, which is a time period when athletes tend to steam past warning signs of injury because, of course increasing your volume or intensity is going to cause some soreness. “But if longevity is your goal, you can’t train like that,” Hamilton says. “You have to deal with the whispers of your body so it won’t need to shout at you. A lot of runners tend to miss the boat—if there’s not a bone sticking out and blood spurting, we’ll plow ahead.”

What’s more, while running and other endurance activities are known to have positive health benefits, there’s evidence that too much endurance training can have negative physiological consequences. “Recent research in cardiovascular science reveals that older recreational endurance athletes face higher risks in atrial fibrillation, particularly in men older than 40,” Berard says. According to some research, endurance athletes who train more than five hours a week at greater than 80 percent peak heart rate are at greater risk for these heart issues.

The bottom line: Take care of yourself, listen to your body, and if you do realize that your last one may actually be your last, own that and try something else, either shorter distances or other sports. Even Meb has said he has no plans to stop logging miles—just not 26.2 of them in one fell swoop.