Why Do Your Toenails Fall Off During Long Distance Running?

Ever wondered why you lose your toenails in long distance running? It could all be to do with friction within the shoe during the running phase.

As I build more and more long runs together in preparation for an upcoming marathon, I have noticed not one but two of my toes have decided to paint themselves a nice shade of bruise brown. Perfect as we come into warmer thong wearing weather!

Reading around the topic I found some interesting information from many sources. The technical term is ‘Subungal Hematoma’ and there are many theories on how this occurs in running.

These include:

  • Repetitive trauma from a poorly fitted shoe as the toe repeatedly hits the end of the shoe (toe box within the shoe).
  • Separation of the nail from the vascular supply through constant rhythmic backwards and forth motion of the toe within the shoe in long distance running.

The theory sourced from our friends over at The Gait Guys goes along the lines of shoes being generally well fitted to the runner, which in theory should reduce the prevalence of toes hammering themselves against the end of the shoe. They explain that the skin of the toe moves at a slightly different rate to the nail bed as the skin is fixed to the base of the shoe, while the toes flex. This creates a slight lifting force on the end of the toenail and as this is repeated over longer distances, can result in bleeding below the toenail, disruption of nerve fibres causing pain, and ultimately may result in losing a toenail.

If you have any running related questions as we hit the peak of the running season feel free to come in to our Sydney CBD clinic and speak with one of our Physio’s, or have a Running Assessment with our Physio Ben.

We also have some great running blogs to check out.

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