I have gotten this question at least once a week from readers and customers combined.
For some unholy reason, folks have been washed into thinking that black toenails, or toenails that fall off are just a part of life when you’re running a marathon. Or a half. Or in some freaky cases, every time you do a long run.
So let’s put this thing in reverse. When is it normal for your toenails to fall off? The first answer is never. Second, if you’ve ever slammed your toe in a door, or had it run over by some sort of vehicle before, usually the toenail that takes the biggest impact will turn black and eventually fall off. It sounds hideous because it actually is.
So why would it make any sense that this should happen when you’re running long distances?
If you’re running in a shoe that’s too small, and a LOT of you are unwittingly doing just that, you may feel fine for a 3, 4, or even 5 mile run. But do much more than that, and your feet, which will naturally swell as you pound them for miles and miles (increased blood flow to that extremity), will cause the toenail of the longest toe to start hitting the end of that shoe. It sometimes will start as a toenail just getting a little sore. And in a longer run situation, say a half-marathon, the toenail, which has repeatedly been slammed into the end of the shoe, will sometimes turn black, and fall off. I’ve seen it happen to more than one toe, as well.
Bottom line, a lot of you are wearing shoes that are too small, and running around and thinking that it’s normal for your feet to have no breathing room.
The solution? Next time you’re in for a shoe fitting, or next time you’re in a store with a Brannock device, (one of the foot measurey things), measure your foot. That is your dress shoe size. So for driving shoes, heels, wedges, and flats, you may wear that size because you’re not going to run a marathon in a pair of leopard ballet flats. Then go up a half to a full size for your running shoes. The way to measure if you’ve done it right? Strap those running shoes on, and sitting in a chair, firmly tap your heels on the ground. Then, stand up, bend over, and SHAKE DAT THANG. Nope, kidding. Bend over, and feel how much space there is between your longest toe and the end of your shoe. You should have a thumb to half a thumbs width, and you should be able to easily curl your toes over with no difficulty. Finally, don’t be dumb and get a shoe that’s like 8 sizes too huge here. If you’re sloshing all over, the shoe is too large, and you need to reel it in.
So the final answer? It is not normal for you to be getting sore black toenails after a long run or a race, and if you are, it’s time to reevaluate what the heck you’re wearing on your feet.