Filed under: blister care, Footcare, Health, Sports, toenails
I get questions by email all the time. Toenail questions are quite common, so I thought I’d post this one. Here’s the question.
“I am emailing you because I have a 50K trail race this Saturday and for some reason I am just starting to get pressure from under my large toenail. It is in its early stages and my nail has not turned black yet, but it is starting to be uncomfortable. At what point do I decide to puncture thru my nail and lance the fluid under the nail? Also, if I should be lancing the fluid, what are your thoughts of using a really thin and clean drill bit (turned by hand) to get thru the toenail? I lost a toe nail once before and tried using a really hot paper clip and needle, but I had a hard time getting all the way thru my toe nail. Any help and advice you can give me would be much appreciated… thank you!”
The answer is pretty straightforward.
Can you recall any nailbed trauma? Once fluid is underneath the nail, the pressure becomes painful You’ll know. If you can see the fluid from under the tip of the nail, lance it there. A drill bit works better than a paperclip. Be forewarned that as it goes through the nail, it can go into the soft tissue underneath, so go slowly. Then press on the nail to expel as much of the fluid as possible. Cover with a Band-Aid for now (tape on race day) but don’t plug the hole with ointment, as it will still need to drain for a few days.
Relieving fluid from underneath a toenail is a simple skill that every runner should know how to perform – just in case. It could be on one of your toes, or the toe of a friend. If you have ever experienced the intense pain of a black toenail with blood or fluid underneath, you’ll appreciate knowing how to fix it.
Filed under: blister care, Foot Care, Footcare, Footwear, Health, toenails
Here are a few foot care tips I wrote to help runners at the Amazon Jungle Marathon. I’ll be there in a few weeks to help with foot care on the medical team. The tips are valuable for anyone doing a 24 hour race, a multi-day event, an adventure race, or a long backpack. Remember, your feet will carry you day to day only if you take care of them.
Start with good toenail care. Trim your nails short and then use a file over the front edge to remove any rough edges. File the tip of the nail so when you run your fingertip over the tip of the toe and over the nail, you don’t feel any rough edges. You can also file the top of the nail if it’s thick. Coming to the race with bad toenails will ensure toe blisters and black toenails.
Make sure your shoes fit well. Have enough room in the toe box for your toes to wiggle. Your feet may swell over the race and you don’t want shoes that are too tight. Some shoes, like Hokas, retain water and become heavy over the days, as they are wet so much of the time. Wet and waterlogged shoes are heavy.
Get good socks. Don’t show up with cotton socks. Socks made with Coolmax or wool are good choices. Injinji toe socks are great. Have several pair and wash then after each day’s stage or have one pair per day. Also don’t show up with old socks or ones with holes in them.
Do whatever you can to reduce any calluses. Getting a blister under a callus can be painful and it’s very hard to find the pocket of fluid for draining. After showering, use a callus file or pumice stone to shave the callused skin from your feet. Then apply some callus cream. This is something that should be done several times a week. Calluses are the result of friction and pressure between your shoes and feet. Make sure your shoes will drain water.
Shoes that hold water inside will increase the maceration effect of your feet being wet to long, leading to wrinkled and soften skin that can fold over, crease, and split open. Check this by filling your shoes with water and seeing whether it will drain out. You can heat a nail (at least 1/8 inch round) or an awl and make several holes at the inside and outside arch, and the heel of your shoes. Learn how your feet respond to being wet for long periods. Do some long walk or runs three to six hours long with wet feet. Try several products like Desitin or similar cream for baby bottoms that works to control moisture on the skin. Google “baby bottom cream” to see many options.
Do not skimp corners on your foot care kit you need to carry in your pack. Have several yards of a good quality tape, several needles to drain blisters, and learn how to drain and patch blisters. The medical team will try and help with your foot care needs, but we can become overwhelmed by the number of people wanting help. Part of your responsibility as a runner is to know how to do good foot care.
Carry a good pair of camp shoes to wear in the camp after each day’s stage. You don’t want to walk around barefoot and doing so will destroy the taping or blister patching done by you or the medical team. Lightweight Crocs, flip-flops, or sandals are easy to strap to your pack. Change into these after running to allow your skin time to heal from the moisture.
Several weeks ago I was interviewed by Gabriella Boston, a reporter for The Washington Post. She emailed me asking whether I was available and when could we talk. When she called we talked for about an hour. She asked all kinds of questions about foot care based on my experiences for runners.
The article came out on the 17th and is worth reading. The title is How Runners Can Keep Their Feet Happy. Sections include, run training, proper footwear, cross training, and foot care. Gabriella interviewed two podiatrists, a physical therapist, and me. Fixing Your Feet is also mentioned in the article. Click on the link in the paragraph above to read the full article. My bet is that you’ll learn something new.
Today’s post is contributed by Gwen Lewis.
Athletes are prone to a number of injuries; torn or sprained ligaments and muscles, bruises, and broken bones. More common, irritating, unsightly and often embarrassing afflictions are situations such as athletes foot and toenail and toe-bed injuries. Athletes foot is a fungal infection that affects the areas between the toes leading them to become itchy, inflamed and painful. In extreme cases, especially for extreme athletes, infection can lead to ingrown toenails and in the worst cases, loss of toenails, which can make practice unbearably painful and slow or halt performance. Read on to discover ways to protect and repair damaged and irritated feet and toenails.
From the ground up
As an athlete, the right pair of shoes makes all the difference when it comes to preventing wear and tear on hard-working feet. A pair of running shoes that are too tight will pinch nerves and lead to ingrown toenails as well as painful bunions, blisters and calluses.
Look for shoes that allow your feet to breathe (mesh, canvas or leather). Shy away from rubber and plastic, which hold moisture in and cause feet to sweat, and infections to flourish. Allow time for your shoes to dry – forgo wearing the same pair of shoes two days in a row. Many people do not realize how important the insoles of a shoe are and what benefits they can give your feet with the right pair. Wear socks made of natural fibers that absorb moisture best, or invest in synthetics that are especially designed to draw moisture away from the foot.
This affliction affects quite a large number of athletes. It is a fungal infection known as tinea pedis, which targets the nails and skin, causing skin to become red, cracked, burnt, scaly and itchy. Sometimes the infection stays mainly between the toes, but in extreme cases it may also appear on the soles and side of feet and spreads to the toenails. It can also be accompanied by painful, oozing blisters. Athlete’s foot is easily spread and can be picked up in common areas such as showers, and can become exacerbated by moist, tight shoes and socks.
Prevent athletes foot by keeping feet clean and dry, and wearing the right shoes and socks as we mentioned above. Avoid walking around barefoot in public areas and wear flip-flops in locker room showers and bathrooms.
Athletes are often prone to extreme cases of damaged and injured toes and toenails. These types of injuries can lead to loss of toenails, and debilitating ingrown toenails. Prevent ingrown toenails by keeping nails clean and clipped short and trimmed straight across. The medical term for toenails that fall off due to a fungal infection or traumatic injury is called onychoptosis or onycholysis, which indicate a separation of the nail from nail bed. If there is trauma to the nail, damage will be characterized by pain, bruising under the nail bed, discoloration of the nail, and ultimately loosening of the nail. If damage is caused by an infection, look out for thickening of the nail, yellow, brown or green discoloration, swelling, pain, itching, flaking, redness, foul odor and possible discharge.
If you see any of these symptoms, there are ways to treat and prevent further injury or damage. Athlete’s foot can be eased by a number of natural solutions; baking soda used as a paste can ease the itch and burn between toes, and a foot soak made of baking soda and salt will soothe affected areas. Plain yogurt is also an instant remedy for athlete’s foot, simply dab on infected areas, let dry and then rinse off. Tea-tree oil is a powerful antiseptic, mixed with olive oil and rubbed on it will clean, heal and soothe dry patches. Calendula is also a powerful herbal healer that has antifungal and anti-inflammatory powers. If your toenails are ingrown or inflamed, clean them with antiseptic, gently pull up the nail and trim what part of the nail you can off. Seek treatment immediately if the area under the nail bed is extremely painful and oozing.
Gwen Lewis is a writer who lives in California. She has a passion for beauty and health and loves to write her articles from experience. She grew up playing soccer and knows the importance of taking care of your feet. She hopes you find these tips helpful to prevent any athletes from foot problems.
Filed under: blister care, Foot Care, Foot Care Products, Footwear, Footwear Products, Sports, toenails
Several months ago I had the good fortune to work on the medical team at the Jungle Marathon Amazon. My specific role was foot care of the 78 runners and to work with the others on the medical team to teach them good foot care techniques. I learned some things that I am calling, Your Event Homework…” By that I mean, your homework is to consider these five things that, if you learn them, can help you be more successful in the event.
Over seven days, I got to know most of the runners. The race offered a one-day, four-day, or seven-day event, and runners were required to carry all their gear and food in a backpack. Hammocks were mandatory and everyone had to carry a mandatory kit of emergency supplies. Because of all the gear and food, some runners limited their medical supplies to the most basic (read: as small as possible). Others had large plastic bins or bags of their mandatory gear. Most had planned well.
As runners came through the pre-race check-in to have the mandatory gear inspected, I talked to a lot of them about their shoes, socks, and – their feet. While doing this, I applied ENGO Blister Prevention Patches into many shoes. While I had a good supply of the patches, this would be the only time to get them into runner’s shoes. Once the race started, their shoes would be wet and the patches would not stick. I noticed that there was a good mix of shoes even though the runners were from around the world.
Then the race started.
Three miles into the race, there was a stream crossing. After that, their feet were almost always wet or full of sand or grit. Here are the five main things I saw.
- At the end of day one, one runner asked for help with his insoles. The sand and grit had worn holes in both heels. I could tell, however, that they were well worn even before he started. We dried out the insoles and I cut away any rough edges. Fortunately, the sun had dried the insoles enough to apply ENGO patches over the holes.
- Some runners had chosen shoes that were minimalist in design, and some did not hold up well in the rough trails in the jungle, where rocks, roots, and plants tore at the shoes’ uppers. Two runners’ shoes were shredded at their sides. The handiwork of one of the runners saved the shoes as he sewed the uppers back together with dental floss.
- Several runners had made bad choices in socks. All cotton socks have no place in any athletic event, much less anything over a 5km race. One runner in particular had low-rise cotton socks suitable for walking in the park, but not a seven-day race in the jungle. Another runner had only two pairs of socks, and the first pair had holes in both heels at the end of the first day.
- Some runners experienced problems with toenails that affected their race. Long nails, untrimmed nails, and nails with rough edges cause problems, which can lead to toe blisters, and black toenails.
- While some of the runners managed their feet by themselves, many came to the medical team day after day. While we were there to help, time and supplies were limited – especially time. Runners that can patch their own feet are ahead of the game. Some had the right supplies, while many others with small mandatory gear kits, did not have the necessary equipment. The medical team worked hard to patch feet as we could. Whenever we could, we made sure the runners saw what we were doing so they learned how to do it themselves. By the end of the race, I saw more that a few runners that were working on their feet and helping others.
Lessons to Learn:
- Make sure your insoles are in good shape. Many runners fail to remove their insoles and inspect they – to see if they need replacing. Most standard insoles are flimsy and should be replaced after several hundred miles. For a $25-$30 investment of new insoles, you’ll gain support and comfort. Investing in a marathon, ultramarathon, multi-day race, can be costly. Yes, there’s the money side, but there’s also the gear required, time spent in training, and travel. This is not the time to skimp on footwear. Chose good, high-quality shoes – preferably a design you have worn before and know works on your feet. And whatever you do, don’t wear old shoes that have seen better days.
- Invest in good, high-quality socks – new socks – not some dug out of your socks drawer that are threadbare. Find the right socks for your feet. Try Injinji socks if you have toe blister problems. Try a thin liner with a bit heavier outer sock. Try several types of socks to find the right amount of cushion and support.
- Learn how to care for your toenails. That means how to trim them and file them smooth so they don’t catch on socks or hit on the top or front of the shoe’s toe box.
- Runners can help themselves by learning how to manage their feet and treat any blisters that might develop. While some events have medical personnel and staff experienced in foot care, many don’t. Or they don’t have the best choices in supplies. Better to be prepared and know what your feet need – and how to manage your own feet. Then if there are people providing foot care, you can use them, and tell them if you need or want certain things done.
In the same way you train for an event, and invest in clothes and packs, and food, you must invest in your feet.
I have a large file of feet pictures on my computer. Pictures of toes, heels, balls of the feet, and arches. Pictures of blisters of all shapes and sizes. In addition, I see all kinds of feet when I work events. Over the years, I have worked races ranging from short distances to ultramarathons, to multi-day stage races.
I am probably one of a limited number of people in the world who gets excited at photos of bad feet. I like them because they tell stories.
The first full multi-day event I worked was Racing the Planet’s Atacama Desert six-day stage in the high desert of Chile in 2004. The stressors of being on your feet for long distances day-after-day for six to seven days often bring out the worst in feet.
A lady in that race wanted us to remove her toenails at the end of day two. Another runner had the worst case of trench foot I have ever seen. That was nine years ago and my techniques have changed for the better, but the feet remain the same – bad!
I believe that feet tell a story.
The photo here is from the Racing the Planet Iceland. I don’t know the owner of the feet. I don’t know the level of training and experience the person had prior to this race. I also don’t know what experience this person had with foot care planning before a race and during the race.
Here are my observations about the story behind these feet.
- Almost every toe has something going on.
- The photo was posted online for stage five, meaning the runner had to tolerate these toes for four plus days.
- These blisters don’t typically happen in one day. My guess is they started on day one, progressed to blisters on day two and then got worse.
- My bet is the shoes’ toebox was too short in length and/or too low in height.
- The runner may have worn two pairs of socks, which could have made the fit too tight.
- The toenails don’t look too long but it’s hard to see if they have any rough edges or are thick, both of which can lead to toe blisters.
- These toes scream pain – especially if they are encased inside shoes.
- It’s possible the toes received some degree of care, but it is hard to tell from their condition.
- Four of the toes have major trauma.
- We cannot see what is going on under the toes, but from the outside edges of the big toes, you can see blistered skin of the left one and maceration on the right one.
- The left big toe has blood showing in the blister on the outside edge.
That’s a lot of information pulled from a photo. I wish I knew the toes’ owner. It would be nice to learn more about his/her race. What shoes and socks they wore. How the trauma to the toes progressed day-to-day. What care they received. Whether they finished the race.
My guess is that with proper care, much of this could have been prevented. That care could have included lubricants, moisture control skin protect, tape, modified shoes, and nail care.
What story do your feet tell?
Here’s the link to the Racing the Planet’s Iceland race. Racing the Planet does four desert races every year called The 4 Deserts: the Gobi in China, the Atacama in Chile, the Sahara in Egypt, and Antarctic. Every year they add a new location for that year. Past sites have included Australia, Nepal, Namibia, Vietnam, and 2014 will be in Madagascar. You can check them out at Racing the Planet.
Filed under: blister care, Foot Care, Footwear, Health, Sports, toenails
Which is more important, blister prevention or blister treatment?
For more than 17 years, I’ve taught foot care techniques to anyone who will listen. I have taught classes at running stores, REI stores, events, and more. In addition, I have worked medical at many races, helping provide foot care to participants. These races have been in Death Valley, Chile, Costa Rica, BC Canada, Colorado and Washington, and many in California. This year I will be at Western States 100, Badwater, the Gold Rush Adventure Race, the Jungle Marathon in the Amazon, and hopefully at races in Colorado and Namibia.
I have never counted the feet I have worked on but I would put the number well over 3000. I remember one race in Colorado in 2010 when I saw the same lady 10 times. It was a six-day stage race and she’d come in every evening and morning! I’d patch her feet in the evening and she’d take it off when she went to bed in her tent. She had foot wear issues that gave her blisters on top of blisters. She was never into prevention mode – only treatments.
In this picture, taken from the cover of the 5th edition of Fixing Your Feet, we see treatment taking place. I love the picture. I even know whose foot it is. What I can’t tell you is what he did for prevention. I wish I knew.
My question in this blog post is what should we spend more time on, blister prevention or blister treatment?
Prevention can take many forms: good choices in footwear, the right socks, lubricants and powders, toenail care, skin care, taping, Engo patches, correct lacing, the right insoles, and training and conditioning.
Treatments likewise offers many options: blister draining, many different types of patches, taping, ointments and salves, a multitude of tapes, wraps and straps, silicone pads, Engo patches, toe caps, and lubricants and powders.
So here are a few questions:
- Does prevention last only until the race starts?
- What are your best prevention options?
- How much do you count on aid station personnel to manage treatments?
- Do you know how to treat your feet?
- Do you carry materials to treat your feet?
- What are your best treatment options?
- How well do you understand blister formation and prevention?
For 17 years, athletes have had Fixing Your Feet as a resource to learn important information about foot care. As I patch feet at races, I try to educate the athletes about what I am doing and why, and what could have helped in their feet. If crews come to me for advice, I try to help them too. I have watched athletes and crews work on feet with materials and using techniques I have long preached.
In general, foot care has advanced over the years. Shoes, socks and insoles have become light years better. Lubricants, powders, blister patches, and our tools are better. People interested in foot care are trying new blister patching techniques.
All this is good because every day there are new athletes coming into running, adventure racing, hiking and thru-hiking, walking, and other feet stressing sports. Let’s make sure they understand the importance of prevention before treatment.
Lisa de Speville, who lives in Johannesburg, South Africa, is a close friend who often emails with insights on blisters and foot care. Yesterday I received the following email and asked whether I could share it with my readers. Her email contains insights on little toe blisters, issues with minimalist shoes, and fit of shoes modified with gaiters.
Here’s her email.
Last week I ran in the 5th edition of the Namib Desert Challenge. I had the pleasure of running in their inaugural event back in 2009 and so it really was a treat to return. Great event, well-organized, wonderful region of Namibia and a lovely warmth and hospitality from the organizers.
Since about June last year I’ve been running in more minimalist shoes. I’ve always enjoyed a softer, more tactile shoe and I took to the pair of Asics Gel Fuji Racers that I won at a race immediately. I liked them so much that I was even running them on road. I like to keep trail shoes for trail and road shoes for road so in about August I bought a pair of Inov-8s. The brand is relatively new in SA so I thought I’d give them a try (my road shoes have been Addias Response or Supernova for more than 10 years). Let’s see… I’m in the Men’s Road X 255 (6mm lift), which is not flat as a pancake. Both the Asics and Inov-8 are quite roomy and my feet enjoy this.
Certainly over the past three months I’ve felt a change in my soles – more firm and muscular, which stands to reason if they’re strengthening and working harder. It is muscle after all. Before I started adventure racing and running ultras my feet were 1.5 shoe sizes smaller and I have a feeling that my feet are another half-size bigger in recent months.
So, the time comes for the Namib Desert Challenge and I get my favorite race shoes stitched with Velcro for my desert gaiters. Everything is ready. I hadn’t worn these shoes for a while. They were still relatively new – perfect for going into a multi-day race – as I’d bought two pairs of the same at an end-of-range special many months ago. I’d flattened the first pair so they were in no condition for this race.
When I put my foot into the shoes in the days before the race to get a feel for them again they felt a little tight, especially across the width of my forefoot. And more than just newness. This is why I figure my feet are a certainly a half-size bigger. Nothing that some lace-loosening wouldn’t sort out.
I started to develop what I call ‘triangle toes’ almost immediately. This is the one thing I avoid like the plague because I hate having sore little piggies. Triangle toes is where the underside of the little toe – and sometimes the neighbor next door – becomes pointed. A blister forms here and can result in a ‘toe sock’ – where the skin of the whole toe comes off, almost like a sock. It’s nasty and I not very fondly recall some incidents of almost toe sock about 10 years ago in adventure races. Since then I take special care pre-race to make sure my little toes stay ’rounded’ and that any harder, potentially triangular skin, is filed off regularly.
I dealt with the resulting blisters – stage 2 or 3 they came up on both little toes – by draining, leaving overnight to dry and then added some tape for the stages. I tried to flatten the triangle under the tape, but it ended up triangular again at the end of the stage. For the most part they gave me little trouble.
At the start of the 55km ultra stage on Day 4, I was debating whether to remove the inner soles for give my feet more room so that the little toes would have more width. It felt odd so I started with them in and my laces not too tight. By the first waterpoint I needed to change something so I took out my innersoles. I had to re-tape a toe a little way further because the change in space altered something. After this, no problem.
I’ve never run in shoes without innersoles and it really changes the feel of the shoe. The Adidas Response TR shoes really suit my feet – I’ve been running in them for 13 years! Taking out the innersole changes them to the Inov-8 feel. Flat and bland inside, which isn’t a bad thing – just different. It also makes the sole feel so much more flat and less cushioned – I felt like I was running in a non-cushioned shoe… for 47km!
Fortunately I was none the worse for wear but, for sure, if my feet hadn’t been conditioned from 10 months of running in ‘flat’ shoes my feet would have felt it. I ran the 5th and final stage without the innersoles too.
Aside from the triangle toes, my only other foot ailments included an injured big toenail on my left (not sure why? perhaps from a kicked stone?). The toenail developed a blister underneath, which was easily solved by drilling into the nail to relieve the pressure. I only discovered this one after the second stage when inspecting my feet. The other blister came up on the long stage under the ‘joint’ of my left big toe, where it connects to the foot. I have some scar tissue there from when I sliced my toe open many, many years ago. It occasionally twinges and at this race, on the long day, I caught exactly this spot so many times on rocks – prodding in. I couldn’t have purposefully aimed as many times in that exact spot! Again, not a bother (fortunately!) and easily solved by draining. On the final stage I didn’t hit it once and so it didn’t flare up again. For the rest, beautiful feet after 230km.
As I haven’t had triangle toes for years, this confirmed for me that width-ways just-that-little-too-tight squeezing of the forefoot is almost guaranteed to cause triangle toes and the resulting underside blisters, with the potential for toe sock, somewhere you do not want to go. In fitting shoes we tend to focus on the amount of space at the front of the shoe but definitely need to pay attention to left-right wiggle room.
Finally… one of the runners had really badly injured toenails (most of them) and the tops of his toes. The reason… too small desert gaiters for his shoes! I don’t know what kind they were (not mine) but they were Velcro attached (around the shoe) and pulling at the top and front of his shoe and causing toe injury. Live and learn.
Lisa de Speville
Johannesburg, South Africa
Adventure Racing: www.ar.co.za
Last week I wrote about prevention and being proactive. I emphasized that you are the key to prevention. I want to share an email I received from a friend that is a great example of this in action. Lisa told me about her friend and gave me permission to share the story:
My friend ran a 50km x 2 (100km total, over two days) race a few weeks ago. Over the past six months he has put a lot of work into his running training and has been running beautifully.
I was away so when I got back I dropped him a text to see how his race went. He told me what happened and in the conversation said that he would be losing many of his toenails. I ask why and he said he forgot to cut his toenails.
As you can imagine I didn’t reply to this at all because I would have thrown some insulting words his way.
He has been trail running for more than a decade and been doing adventure racing for over a decade. He spent a fairly sizable amount on his race entry and it must be about 900km to travel to the race. He put in six months of training to get stronger and faster. And he forgot to trim his toenails! This is more than elementary and is totally stupid. It’s tough to have sympathy (I have none!) when friends do silly things like this. He knows better.
This story speaks for itself. I have often talked about how athletes spend a lot of time and money in preparation for an event but fail to plan for good foot care. More times than I care to remember, I have seen athletes quit a race or be pulled from a race because of feet gone bad. It doesn’t have to be that way.
I’ll say it again, you are the key to prevention.
Filed under: blister care, Foot Care, Footwear, Health, Sports, toenails
I believe strongly in prevention as a proactive measure in foot care.
Tim Noakes’ sixth law of running injuries must be heeded—any running injury can be cured only after the cause is found and eliminated. All of us who run, hike, or adventure race at some point have problems with our feet or sustain foot injuries. The prevention chapters are numerous and lengthy because many factors contribute to foot problems and injuries, and for every factor, there is a preventive measure that can reduce or eliminate it. Prevention is the key to saving your feet. Dave Scott, a good friend and ultrarunner, put the foot problem in proper perspective: “When you don’t take care of your feet during a long run or race, each step becomes a reminder of your ignorance.”
It’s very easy to relinquish our responsibility for preparedness and let someone else dictate what we should do. We tend to listen to those whom we look up to and to those who are more experienced. In many ways this is OK, and it is often the way it should be. However, only you can determine what works for your feet.
Knowing your prevention options is important. That’s being proactive. I get emails every week from athletes who are looking for answers for their feet issues.
Some have my book but others don’t. Some have the book and have gone through the chapters to find possible treatment options. Others have the book and haven’t read it – and want me to answer their questions.
I try. Sometimes it works and sometimes not. While I answer from my experience and knowledge, I don’t have your feet. And that’s important.
Your feet have your abnormalities (hammer toes, bunions, thick toenails, skin that calluses, a tendency to athlete’s foot, a tendency to blisters, etc.), your ankles, your shoes and socks, your fit (good or bad), your training base, your stride and gait, and more.
You are the best person to find what works for your feet. Others may give suggestions. Fixing Your Feet can give suggestions and I may offer a few via email or in this blog, but you need to try them on your feet to find the one that works best.
You are the key to prevention.
Please, don’t show up at a race with a bad case of athlete’s foot, holes in your socks, shoes that have outlived their support, insoles that are flat as paper, toenails that are long and untrimmed, shoes that don’t fit, huge thick calluses, blisters that are unhealed, thick nails from untreated toenail fungus.
Yes, I have seen all of these.
Again, you are the key to prevention.