“So, how many toenails did you lose?”
Marathoners commonly hear this question from people who assume that black toenails or toenails falling off are inevitable when running a marathon. Some runners even think of getting black toenails or losing them as a rite of passage for distance runners.
But it’s possible to prevent these painful, unsightly annoyances. Here are tips to prevent and treat black toenails.
What are Symptoms of Black Toenails?
First, you may feel some pain underneath your toenail while running, especially after a long run. The toenail will then appear blackened, due to dark, congealed spots of blood between the nailbed and nail. The big toenails are the most likely ones to get bruised. The pain often subsides after a few days, but the toenail will stay black or bruised.
The nail will usually fall off when a new nail eventually grows in. But it’s not as bad as it sounds! Your toenail will not fall off until another has started growing underneath it. The new toenail will at first be softer and rougher than the old nail, but it will eventually get harder and smoother, just like your other toenails.
What Causes Black Toenails?
Black toenails are caused by constant rubbing of your toe against the front of your shoe.
Runners who are training for a marathon or do a lot of downhill running are the most likely candidates for black toenails because their toes are constantly rubbing up against the front of their shoes.
Runners who run in shoes that are too tight are more likely to get black toenails. You’re also more likely to get black toenails if you run in warmer weather because your feet swell more when it’s hot.
How to Prevent Black Toenails
To prevent black toenails, make sure that you’re wearing the correct running shoe size. They should be at least 1/2 size bigger than your street size. Make sure you have plenty of room in the toebox.
When shopping for running shoes, make sure you go to a specialty running store and have the salesperson measure your feet. Even if you think you know your shoe size, your feet can get wider and longer (due to pregnancy, falling arches, etc), even as an adult. Also, it’s best to try on new running shoes after a long run or at the end of the day, when your feet are already swollen.
If you’re wondering if your current running shoes are the correct size, check the location of your big toe. If it’s pushed right up against the front of the shoe, they’re too small. Another easy way to check the fit is to remove the shoe’s insert and stand on it. If any part of your toes are hanging over the end of the insert, your running shoes are too small.
To prevent black toenails, you also need to trim your toenails regularly. Keep your feet dry for as long as possible during your long runs. Be sure to wear good wicking running socks, not cotton ones. Lace your shoes tighter along the front if you’re doing a lot of downhill running.
How to Treat Black Toenails
Once you have a black toenail, it’s best to leave it alone, as long as the pain is manageable. The pain is usually the worst on the first day and then lessens each day after. The damaged part of the nail is gradually pushed off, and a new nail will replace it.
Don’t force the old nail off — it will fall off on its own. If at any point you notice redness and infection, see a doctor.
More on Running and Foot Issues:
- How to Prevent Burning Feet While Running
- How to Prevent and Treat Foot Blisters
- Why Does the Top of My Foot Hurt?
