The Lifecycle of a Runner’s Toenail

You will lose your toenails, I had been warned a couple years ago when I began to vocalize my interests in marathon running. How could running cause toenail loss? Would they grow back? Will it hurt? Putting these questions aside, I pursued marathon training, and three marathons later have one casualty to report.

I lost my toenail 4 months after a 20 mile training run using a brand new shoe a half a size too small. Five miles into the run, I felt my feet swell and pound against the toe box. My toes banged against the shoe, painfully, all the way home. The next day, with a green toenail, I limped to the shoe store and traded in the culprit for a half size bigger. Over the months that followed, I noticed my toenail changing colors. Eventually, it fell off, and this toenail in the coffin put to rest my questions about running and toenail loss.

  1. How could running cause toenail loss? While there is an association between running and toenail loss, I believe that it is not causal, and my experience resulted in a model to account for the mechanism of loss: “The Unfit Shoe-Nail Model.” A shoe that does not fit, mediated by miles of running, could cause the loss of toenails:unfit_shoe_toenail_model
  2. Will the toenails grow back? Yes, after turning green, blue, purple, brown, yellow, and gray, the dead nail on my toe tore in half, and fell off piece by piece. Beneath the shattered pieces, a new toenail had been born, a stub thinner and shinier than the rest.toenails
  3. Will it hurt? The purple/blue/green stages hurt in the way that a bruise hurts when met with pressure. The remaining stages passed painlessly.

The lifecycle of a runner’s toenail is like that of any other person; vulnerable to assault and self-correcting, perhaps like a lizard generating a new tail.