During the 13 weeks I spent training with the NAZ Elite professional running team in Flagstaff last summer, I did a few workouts with Sarah Crouch, not a member of the team but an accomplished pro with a 2:32 marathon on her resume. During a couple of these sessions, it was apparent to both of us that Sarah was working harder (i.e., suffering more) than I was, which seemed odd to me because my goal was to run 2:39 at the Chicago Marathon, whereas Sarah hoped to run 10 minutes faster. Any knowledgeable observer of these workouts who knew nothing about Sarah’s and my respective backgrounds and ambitions would have predicted that I would beat her in Chicago, but in fact she beat me by 63 seconds, and would have finished even farther ahead of me if she hadn’t run the first half in 1:16:00 and then cratered.

Afterward, I couldn’t help but wonder: Is Sarah just plain tougher than I am? Is it possible that she is able to do more with similar physical capacity because she is able to run harder and push closer to her limit? Although I like to think of myself as one tough sonofabitch on the racecourse, I couldn’t dismiss this hypothesis, in part because I had no better explanation and in part because I’ve seen a good deal of evidence that elite endurance athletes are exceptionally tough mentally. Indeed, their next-level toughness is one of the reasons they’re elite.

Some of this evidence is scientific. In a fascinating 1981 paper published in the British Medical Journal, Stirling University psychologists Karel Gisbers and Vivien Scott reported finding that pain tolerance was higher in elite swimmers than in club swimmers and higher in club swimmers than in noncompetitive swimmers. More recently, a team of researchers that included my friend Samuele Marcora found that professional road cyclists scored significantly higher than recreational cyclists on a test of inhibitory control, or the ability to resist immediate temptations (such as the desire to slow down or stop to avoid the suffering of hard exercise) in favor of staying focused on a long-term goal (such as getting to the finish line in the least amount of time possible).

Other evidence of the superior mental toughness of elite endurance athletes is anecdotal. If you spend a lot of time interacting with both elite and nonelite endurance athletes, as I have done, you notice a clear difference in how the two groups (with some individual exceptions, of course) view the pain that their sport inflicts. Elite athletes tend to embrace the pain, or at least accept it. As NAZ Elite member Scott Fauble said in the documentary film 183.4, “I can put myself super deep into this well [of pain]. This is something I’ve known from a young age I was good at. As I’ve kept exploring deeper and deeper for longer and longer periods of time, I’ve just found more and more space there to be myself and live. That is a place where I am at home.”

By contrast, recreational endurance athletes tend to fear and resist pain. For them it is a problem to be avoided, wished away, and at most tolerated, but only up to a point, whereas for the elites it is information and an integral part of the racing (and training) experience. The title of this article is taken from a famous quote from Percy Cerutty, a legendary Australian running coach from the mid-20th century, who often harangued his athletes with the phrase, “Faster, it’s only pain!” as he stood trackside watching them suffer.

If you want to be as mentally tough as the elites, your first step is to recognize the deep truth hidden in Cerutty’s directive. Pain is not proof that you can’t go faster, nor evidence that you’ve reached your physical limit. It’s an illusion. You can go faster. All you have to do is try, and accept the extra pain that comes with it.

These ideas are explored in depth in Alex Hutchinson’s new book Endure, which I haven’t read yet but is next on my list. Based on the extensive writing Alex has already done on this subject, though, I do not hesitate to encourage you to check it out. I’ll share some thoughts about it in this space after I’ve gone through it.