As a 56-year-old perennial marathoner (I’ve done the NYC marathon 18 times), I recognize a lot of myself in this article. In my mid-50’s, I also started dabbling in Spartan races, and I definitely take pride in the fact that I can beat about 80% of the overall field in those events (I fare worse against the guys in my age group, to prove your point).

One thing that all of these extreme sports do is to leave you with a lot of constitutional strength. I’ve had a vivid illustration of that phenomena recently. This past March, I was diagnosed with stage 4 lymphoma, and started chemo in April. That’s about when training for the November marathon is supposed to start).

I’m about halfway through chemo and training at this point, and both are going great. Chemo weeks are bad, but I’m at full speed during the intervening weeks. I’m finding that I’m having a different experience than many chemo patients. I attribute a lot of that to the fitness level that you get from maintaining a rigorous training program over the course of decades. Marathoning has also given me the recurring experience of dealing with discomfort in the pursuit of a larger health goal (a 20-mile run and a chemo session wipe you out in ways that are analogous).