Hello. I'm Hiroki, a member of the OLENO staff.
Just the other day, I participated in a 23-kilometer trail running race. After the race, I went to a hot spring and noticed that my toes were completely black . It's been about a month since the race, and my toes are still black, so I've been racking my brains over what to do about it.
Anyway, while I pray that it will be cured by summer, I have thoroughly researched the causes and measures to prevent my nails from becoming black again , so if you are a marathon runner who is suffering from the same problem, please refer to this article.
Impact to the nail is the cause of black nails (runner's toes)
The official name for black nails is subungual hematoma, and the cause is as I imagined: internal bleeding caused by repeated pressure and friction on the nail. I didn't get black nails when I ran about 10 kilometers, so it seems to be more common when running long distances. (Apparently, black nails are more common at full marathon level.)
Digging deeper into the causes,
There are four main causes, so we will look at each one in detail along with countermeasures .
1. Mismatched shoe size and fit
2. The impact of running style and form
3) Lack of nail condition and care
④The effect of socks
1. Mismatched shoe size and fit
- Running shoe size and fit issues
If you wear shoes that are too small , your toes will be compressed and your nails will always hit the shoes . Conversely, if you wear shoes that are too large , your feet will slide forward inside the shoes and your toes will hit the front of the shoes every time you run.
-Shoelaces are loose
This is an easy one to understand: your foot tends to slide forward inside your shoe, causing your toes to hit the front of the shoe.
→ It is best to use a heel lock or lacing technique for runners to reduce back and forth movement inside the shoe.
2. The impact of running style and form
・How to run on your toes
Runners who run on their forefoot tend to put weight on the base of their big toe . When they run at high speed, the pressure on the toe can make the nail more susceptible to internal bleeding. (Indeed, when I was an athlete and ran the 400m, my nails would often turn black after races.)
→When going downhill, shorten your stride and try to place your feet as close to horizontally on the ground as possible.
3) Lack of nail condition and care
- Nails are too long
If your nails are long, they are more likely to hit the inside of your shoes while running, and each time they hit the shoes, the nail bed (the skin under the nail) is compressed, causing internal bleeding. Surprisingly, wearing thick socks makes it even more likely for your nails to be compressed.
Improper nail cutting
I had no idea about this, but apparently if you cut your nails in a rounded shape , the edge of the nail will be more likely to hit your shoes and be damaged. On the other hand, if you cut your nails too short , the support for the nail will be weaker and the base of the nail will be more likely to be damaged, so that's not good.
→ It is recommended to cut your nails square so that they are of a suitable length and can be firmly supported.
④The effect of socks
- Thickness of socks
If your socks are too thick , the space inside your shoes will be narrowed, and pressure on your toes will increase . This will cause your toes to constantly hit the inside of your shoes, making your nails more likely to turn black. Thick socks can be counterproductive, especially if you're wearing tight running shoes.
- Grip strength of socks
Slippery socks or socks without any grip (like most running socks made from silk or synthetic fibers) make it easier for your foot to slide back and forth inside your shoe , which naturally means your toes will hit the front of your shoe more often, especially when going downhill.
→ By wearing running socks of a moderate thickness (not too thick and not too thin) that are compatible with your shoes and have strong anti-slip properties , you can prevent your feet from slipping inside your shoes even when going downhill.
I have summarized the causes and countermeasures above.
1. Mismatched running shoe size and fit
2. The impact of running style and form
3) Lack of nail condition and care
④The effect of socks
You may be able to prevent black toes (runner's toes) by simply improving one of the above points ① to ④, but you may not be able to prevent them unless you improve all of ① to ④.
For now, I plan to take measures by immediately implementing ①, ③, and ④, but if anyone is looking to improve their condition due to " ④ The effect of socks," please leave it to OLENO !
OLENO continues to develop socks specialized for running, and the ULTIMATE series for trail running in particular has become an essential piece of equipment for many athletes who suffer from foot problems .
The socks themselves are thin, but to compensate for this, we use super-grip silicone rubber with our own technology to prevent the socks from slipping inside the shoes. Incidentally, I wore socks from another company during this race as part of my market research.
*An experiment to see how non-slip it is. Click to watch the video.
In addition to runner's toe, the shoes are designed to be effective in preventing other foot problems that can occur while trail running or running, such as sweaty feet , peeling skin on the soles of the feet , and blisters .
Be sure to try out OLENO running socks, which are also used by Japanese Olympic and trail running athletes!
Click here for the ULTIMATE series
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