Marathon runners often complain of runner’s toe. Some even do so with even a sense of pride, like a rite of passage. It’s one of the most common running injuries out there.
What is runner’s toe?
Also called runner’s toenail, runner’s toe is a condition where the area under and around the toenail begins to turn black. This can happen from getting crushed, stubbed, or putting repeated stress on the area.
This alteration in color is due to a small bleed under the toenail, also known as a subungual hematoma.
In this article, we speak to the experts on the causes of runner’s toe, as well as how to prevent and treat a black toenail from running!
Let’s jump in!
What Is Runner’s Toe?
Dr. Jordan Duncan, owner of the sports medicine clinic Silverdale Sport & Spine, sees runner’s toe (or runner’s toenail) often.
“As the runner grips their toes into the sock liner of the shoe, the soft tissues of the toes are being pushed back under the toenail, which causes disruption of the small blood vessels under the nail,” he explains.
While this can happen to anyone, runners are especially prone. Running continuously smashes your feet against the toe boxes in your running shoes – the part at the end that covers and protects your toes.
The skin on your feet is thick, but hitting any area of your body over and over is bound to eventually do damage.
Many of the patients Dr. Duncan sees are runners with hammer toes. “Hammer toes, which usually occurs in the 2nd through 4th toes, are where the end of the toe is bent downward,” he explains. “Hammer toes tend to indicate that the individual has been clenching their toes for a long period of time.”
Getting a black toenail from running may be annoying, but not the end of the world, as long as you know what to watch out for and how to treat it.
Symptoms of Runner’s Toe
People with runner’s toe – or runner’s toenail – can expect to experience:
- Sharp, throbbing pain
- Red, maroon, or black-purple discoloration under some or all of the nail
- Swelling or tenderness at the tip of the toe
While mostly harmless, runner’s toe can look pretty gruesome.
A buildup of blood underneath the nail bed can cause it to push up. In some cases, the nail will gradually loosen and fall off.
This doesn’t happen right away, usually occurring over the span of a few weeks up to six months. This can be a long time to wait, but the pain should subside in no more than a couple of days.
5 Effective Ways to Prevent Runner’s Toe
1. Wear the right shoes
Like any sports injuries, many of the issues that plague runners come from not investing in the right equipment. Your shoes are essential for the entire activity.
While great deals can be found on exercise wear such as jackets and headbands, you never want to put price over comfort on your shoes. Cheap material means they wear out earlier, so you’ll likely end up spending the same amount over time anyway.
Choose running shoes that will last.
To avoid runner’s toe, choose a size where you have enough room at the end so that your toes aren’t pressed against it. At the same time, don’t go so large that your foot can slide around.
That may make it even easier to cause injury. Aim for one thumb width away between the tip of your toe to the toe box.
2. Trim your toenails.
Clipping them short will make sure that the first thing hitting the toe box inside your shoe is the toe itself, not your nails. The shorter they are, the less likely they are to make contact with any part of your shoe.
Beware not to cut them too short, though, or you may deal with another problem, the ingrown toenail. Cut straight across so the skin around your nail doesn’t try to grow over it.
3. Lace your shoes properly
Even with the perfect running shoes, lacing them correctly is still an important part of getting the most out of them.
But I’ve known how to tie my own shoes since I was five, you might say.
For basic walking, you’re right. But running, especially distance running, comes with a whole new set of challenges you have to make sure you’re prepared for.
Studies show that the method of lacing can significantly influence pressure in the foot. Before hitting the track or road, your laces need to:
- Allow proper blood flow
- Have room for flexibility
- Have enough tightness to prevent rubbing
- Avoid putting pressure on delicate areas
- Keep your heels steady – to prevent ankle sprains
With proper lacing technique, you can get the most comfort out of your shoes possible.
How do you do this? Take into account the shape of your foot and how it feels inside your shoe. Change up where the lacing pattern crosses diagonally and where it crosses horizontally to tighten and loosen different areas.
Secure the holes at the top of the shoe by creating an extra loop at each hole, then threading the lace through the loop once again.
4. Wear moisture-wicking socks
Damp toes are slick, and that slip could cause your feet to slide into the toe box with more force than before. Prevent this with some solid quality socks that wick away sweat and keep your feet firmly in place.
There are socks specially geared toward runners that provide extra grip inside your shoe and more cushion in the toes. Some also have a double layer of fabric for extra moisture absorption.
5. Use toe protectors
Silicone toe caps guard against friction and provide cushion from the repeated motion of running. They stretch to fit any toe and fully cover it from all sides. These are great for cushioning and stopping the friction that causes blisters. Some can also be cut down to size, allowing a perfect fit customized to your foot.
How to Treat Runner’s Toe
Let it grow out
While this requires a lot of patience, most cases of runner’s toe don’t require any action at all. It will simply grow out with the nail plate and resolve itself.
You can expect the black and blue discoloration to stick around for a few weeks to months, as toenails grow much more slowly than fingernails. By the time the old toenail falls off, a new one should be growing underneath in its place.
It’s hard to leave injuries like this alone, but resist touching it too much. Picking at the area can cause open wounds that could get infected and make the problem worse. We suggest wearing socks when relaxing at home for a while. That way the color doesn’t keep your attention, tempting you to mess with it.
The body is an amazing, self-healing machine. Let it do its work.
Have a podiatrist drain it professionally.
If you’re feeling pain or a lot of pressure underneath your nail from the blood, you can visit your doctor’s office for a procedure called nail trephination. This drains extra fluid from the wound.
Your doctor can use a device to melt a hole in the nail or use a needle. You typically know when this is necessary within the first two days, either by pain that doesn’t ease up or seeing damage to the nail.
We do not recommend trying to do this yourself at home!
You might see articles online on how to drain it yourself. But the toenail is a thick, complex area, and bacteria can easily get trapped in there. It could get infected, and you could also cause permanent damage to the nail bed.
So not only will your running downtime be increased, you risk far worse consequences: these involve losing more than just your toenail. Don’t risk it!
When Fixing Runner’s Toe Needs Help from the Experts
When the pain lasts more than a couple of days after draining, it’s time to see a doctor for more.
Head to your podiatrist again if you notice these signs:
- The base of the nail is damaged
- There’s a deep cut or laceration
- It doesn’t stop bleeding
- It looks or feels infected
Your doctor may need to prescribe medication or stitch up any deep cuts. They may also want to X-ray your toe for any broken bones. If the black area covers more than half the nail, the doctor may choose to remove the nail entirely.
Infection can cause complications quickly if not caught and treated. Be aware of the signs, such as:
- Fluid or pus
- Increased swelling and redness
- Worsening pain
- Red streaks in the skin
- Throbbing or heat in the toe
With the right care, runner’s toe doesn’t need to set you back much time at all.
Cut back on running downhill.
You’ll be back into your marathon training before you know it.
Having the right plan can prevent these kinds of overuse injuries from happening, as they keep you on a gradually increasing schedule. Be sure to download one of our free marathon training plans to get into race day shape safely!
Take Your Running Further With Our Resources...
Half Marathon Resources
Marathon Training Resources
Ultramarathon Training Resources