Thoughts about Endurance Athletes

Running across America goes far beyond what most people do in their sporting life. Richard Donovan did it the year after having both of his knees partially replaced. In this interview with Jeff Greenwald, Dr. Kevin Stone discusses some approaches to the care of endurance athletes.

Richard Donovan Running on Partial Knee Replacements

Ultra runner and bilateral partial knee replacement patient Richard Donovan running down Forrest Gump Highway as part of his 3000+ mile cross country run. Photo courtesy of Richard Donovan.

Kevin, can we get a little background on your experience working with endurance athletes?

Dr. Stone: Sure. I've been an orthopaedic surgeon since 1988 and worked with a wide variety of athletes. My deepest exposure early in my career was to winter athletes as I traveled with the U.S. Ski Team for a dozen years. These are skiers working not only at effectively sprint sports, but also at longer exercise activities at altitude—both in cross country and downhill. Personally, I ran my first marathon in Boston in 1981 and have been in awe of long-distance athletes ever since.

Over the years, I've had a chance to work with endurance athletes in sports like triathlons and Ironman events, century runs, 100K events, and others both in their training and to help them recover from injuries.

Can you describe a few physical changes that can occur in the body of an athlete participating in an endurance sport? Who succeeds and who doesn’t? 

Dr. Stone: Briefly, the endurance athletes who last a long time in their sport do so in part because their biomechanics are excellent. They run smoothly and move their joints through a full range of motion. The mechanics of their running and climbing and hiking and biking are all very smooth. Their biochemistry is also excellent. This means they balance their caloric intake and exercise production well.

And their minds are calm. One of the reasons so many women enter endurance sports in their midlife is that they have left some of life's stresses behind or attained a level of equanimity with those stresses that permit them to focus on endurance sports in a way that they simply couldn’t at an earlier age.

For healthy athletes, there are several obvious big challenges in endurance sports. One, staying hydrated; two, having enough nutrition on board; and three, dealing with the weather and other circumstances of the environment they're in. 

The athletes who try to enter endurance sports but don’t succeed often are the ones with a more inhibited gate; an athletic style with a loss of range of motion and limitations in how they move their bodies. 

What we find is that people can run forever—as long as they don't get hurt. But once they are hurt, if not repaired early and successfully, the injuries change their gait, change their muscle strength, and change the loading inside their joints, which can lead to chronic pain and arthritis. 

Smaller injuries, muscle strains, bruises, and overuse injuries are generally not toxic to the body—especially given the fact that most endurance athletes have trained over time and their muscles are used to multi-hour, multi-mile, multi-altitude exposure. 

How do endurance sports differ from more “explosive” sports—like the hundred-meter dash? Do they face a greater or lesser risk of injury?

Dr. Stone: There are very different risks of injury. In sprint sports, we see acute injuries, like ruptures of tendons and muscles. This comes from going from standing still to moving at maximal speed. We don't see those kinds of injuries in endurance sports. We see more of the chronic muscle aches and pains, or the unfortunate misstep on a trail at night or on uneven surfaces. In some athletes, we see the development of joint arthritis from previous injuries and, fortunately today, that usually can be solved.

Is there a science behind how endurance athletes prepare themselves?

Dr. Stone: The science is broad, and athletes who are successful in endurance sports usually have learned what works for them. For one athlete, it may be shorter interval training leading up to a longer event; where for other athletes, it's about training in the distances or near distances of the event. We see a broad range of training styles, many effective.

Let's say you're in the middle of doing a marathon or triathlon. What are the signs that you might be pushing yourself to the point where injury is likely?

Dr. Stone: Dehydration, excessive heart rate, and strained breathing are the usual signs we see in somebody who's not performing well—and they can be self-monitored while competing. The wearable devices now permit the athlete to adjust mid-performance and diminish the dropout from early exhaustion. The next generation of devices will actually give hydration states, blood sugar levels, and blood pressure measurements in real-time during the event. While these measurements are possible now, they are not integrated into the wearables and into the AI-driven, virtual, real-time coaching programs that are around the corner.

What about afterwards? What methods are critical for an athlete to physically recover right after an endurance event?

Dr. Stone: The best recovery technique after most endurance events is time. That means giving the joints, muscles, and tissues a chance to rehydrate and remote and to calm down the natural inflammation that occurs from prolonged events. Whether or not athletes use an ice bath or a hot tub, whether they use a stretching regimen or a spinning regimen, it's mostly time. Time is the best recovery method.

What do you recommend for beginners who are just taking up endurance sports?

Dr. Stone: I think getting a great coach is the best way to get started. You get up the learning curve of the sport much faster and you diminish your injury rate.

And this is true for everything from running a marathon to riding the Tour de France?

Dr. Stone: It really is. A great coach with experience can help you accelerate your performance much faster than trying to learn on your own.

Before we go, please talk a bit about Stone Clinic patient Richard Donovan. 

Dr. Stone: Richard Donovan is in his early fifties. He’s been running, supporting, and organizing marathons in many countries for years. Years earlier, Richard had torn his meniscus cartilage, the shock absorber for his knee. Millions of people do. After this happens, over time, the knee starts to degrade and collapse on the side where the meniscus has been torn or lost.

Richard’s knee degraded to the point of bone-on-bone, and he could no longer run marathons. So, we did a robotically-guided partial knee replacement for one knee, and then a year later we did a partial replacement on his other knee. 

And he has returned to running marathons. In fact, he recently decided to run across the entire United States— just being completed this summer of 2022—on his bilateral partial knee replacements. He exemplifies our approach at The Stone Clinic, which encourages people to exercise more after partial or total biologic or artificial knee replacement. By increasing exercise, the bones and muscles supporting the joint are strengthened, which protects the implants.  

Richard is a kind of “poster child”— not just for rehabilitation, but for taking on the attitude that having a joint replacement does not mean you have to give up the sports you love.



Richard Donovan entered California earlier this week and will finish his run at Santa Monica Pier this Sunday 7/31. You may see the final leg of his journey by following his photo diary on his Facebook page

For more on how endurance athletes can play for a lifetime, head over to this page with expert guidance from Dr. Stone and inspirational stories from our triathletes and ultra runners.

Medically authored by
Kevin R. Stone, MD
Orthopaedic surgeon, clinician, scientist, inventor, and founder of multiple companies. Dr. Stone was trained at Harvard University in internal medicine and orthopaedic surgery and at Stanford University in general surgery.