Does running barefoot put me at risk of toenail fungus?

Hi My Running Doc!

I have heard that going barefoot in locker rooms can put me at risk of a fungal infection and toenail fungus. Does running barefoot also put me more at risk of a toenail fungus infection? 

Thanks!

Jimmy, San Francisco, CA

Hi Jimmy, 

Great question!  The short answer is no... running barefoot does not actually put you more at risk of getting a toenail fungus infection than running in running shoes.

But before we explain that, let's explain why there is such a high risk of getting a fungal infection from a gym locker room.  People work out at the gym all day long. Most of them shower once they are done. 

So the floors in the locker rooms are continually coated with water dripping off of freshly showered athletes. This leaves the floors in the gym locker rooms perpetually moist. This moisture creates the perfect environment for fungal growth. If you walk around in there barefoot the chances are good you might pick up a fungal infection in the form of athlete's foot.

The same organism that causes athlete's foot is also the same organism that causes fungal toenail infections.

In order to get a toe nail fungus infection you must have a couple of conditions present at the same time.

1. Active fungus and/or fungal spores.

2. Trauma to the toenails.

Much like a gymnasium locker room, running shoes are actually the perfect incubators for toenail fungus. Your feet are like little heaters warming up the inside of the shoes to the perfect temperature for fungal growth.  When you exercise, your feet sweat. The inside of the running shoes are also dark and devoid of sunlight. All of this creates the perfect environment for toenail fungus to grow.  

When you run, the ends of your toes and hence the toenails can bump up against the inside of the shoes. Many marathon runners have witnessed this first hand in the form of black and blue toenails after a long run. It's not a large amount of trauma, just a small amount of repetitive trauma that can cause bruising under the toenail.

If you have this sort of trauma to the toenails when you have foot fungus growing inside your running shoes, the fungal spores and live fungus can get underneath the toenail and start to grow. The result is a  fungal toenail infection.

You know you have thick yellowing discolored toenails indicative a  toenail fungus infection.

When you run barefoot you're unlikely to have trauma to the toenails in the presence of a large amount of toenail fungus or fungal spores that are often coating the inside of running shoes. And in this respect, you're actually a lower risk of getting a toenail fungus infection when running barefoot as compared to when running in heavily used running shoes.

Dr. Christopher Segler, DPM is a marathon runner and 11-time Ironman triathlon finisher.  His podiatry sports medicine practice focuses on convenient rapid treatment of running injuries. He is often invited to speak at medical conferences on the topic of barefoot running biomechanics. You can learn more about running related toenail infections and laser treatment of toenail fungus at www.LaserToenailSanFrancisco.com   If you have a question about a toenail fungus infection or barefoot running injury you can call him directly at 415-308-0833.