Blisters – most runners have had them at one point or another. Whether it’s in the early days from ill-fitting shoes or when you’ve been running for hours and your feet have just suffered from the constant pounding. After many years of running, many of us know what causes our blisters and how to avoid them. That said, they are often unavoidable. But how do you try and prevent running blisters and how do you treat them?

What Causes Running Blisters?

Knowing what causes them is a start! If we know why we get blisters from running, then we can work to prevent them. In the main, it’s to do with friction between the skin on your feet and your running socks. When there is pressure on your skin. 

There are other contributing factors too:

  • Calluses
  • Bunions
  • Long toenails 
  • Trail shoes that don’t fit properly 
  • New shoes that aren’t worn in 

All of these things can lead to greater pressure on specific areas of your skin leading to a higher chance of blisters. 

Things that find their way into your shoe can also be the culprit. If a piece of grit, mud, stone, etc. gets trapped between the skin and the sock, this is going to cause friction and ultimately blisters. 

Preventing Blisters 

There are several measures that can be undertaken to prevent blisters, although they are not entirely preventable. Sometimes, especially when running longer distances, these aggravations are inevitable. Only the other day a friend of mine ran 50 miles and said during those last few miles she could actually feel the blisters popping inside her socks! 

Make sure your shoes fit properly

Shoes that are either too tight or too loose can all cause blisters. The recommendation is to go up a half to a full size more than your regular trainers. Your feet will swell up in the heat and the humidity of running and the friction can lead to blisters. 

Wear moisture-wicking socks

Moisture-wicking socks are socks that will draw moisture away from the skin to keep the foot dry. Merino wool, Coolmax, or bamboo socks are all good choices. Try brands such as Drymax, Injinji or Danish Endurance (one of our favourites) and Red on Socks (another of our favourites). Do not wear cotton socks, they have the tendency to hold heat and moisture which increases friction and contributes to blisters. 

Use lubrication

Apply petroleum jelly or anti-chafing balm like Body Glide to your feet before a run. This will help form a barrier between your skin and the socks. 

Tape or pad them

Many of you will be familiar with KT tape – you can use this to cover toes, heels, and the ball of your feet if you are vulnerable to blisters or have a particularly long run/race. Wrap tape firmly around the area and re-apply regularly to ensure it stays put. 

Keep your feet in good order

Trim toenails regularly, stay on top of calluses with a visit to the chiropodist if needed and consider the shape of your feet. If you do have bunions, a wider trail shoe may be a good idea. 

Treating Blisters

Blisters are inevitable sometimes, no matter how much you try and prevent them, if you are running in wet, humid conditions and are running long, there is sometimes no escaping them. You can take preventative measures and make sure you clean your feet before and after a run but what can you do to treat the blisters?

Can I pop a blister?

No! If you do get a blister, don’t pop it. Popping a blister can increase the risk of infection. Instead, cover the blister with a bandage and let it heal on its own. Instead, you should follow these tips:

  1. Leave small, unbroken blisters alone. They will heal naturally on their own in 1-2 weeks.
  2. Cover large or broken blisters with a bandage. This will protect the blister from infection and help it heal faster. You can use a hydrocolloid dressing, which is a type of bandage that forms a moist environment around the blister and helps to promote healing.
  3. Wash the area around the blister with soap and water. This will help to prevent infection.
  4. Apply antibiotic ointment to the area around the blister. This will also help to prevent infection.
  5. Change the bandage daily or as needed. This will help to keep the area clean and moist.
  6. Do not pop or drain a blister. This can increase the risk of infection.
  7. If the blister is large or painful, you may need to see a doctor. A doctor may be able to drain the blister in a sterile manner and prescribe antibiotics to prevent infection.

If you find yourself getting regular blisters in the same places, it could be that you need to try a different brand or model or shoe, or you need to change the size that you are wearing. They may be certain times of year when you find you suffer more – a bit like chafing – when it’s hot and sweaty, you will find more skin irritations occur. A little prevention, and knowing how to treat them will make your running experience more pleasurable.