Everything you didn’t realise you needed to know about blisters… but will stand you in good stead as you take on your running goals this decade.
Truly the worst enemy of every runner (unless you’re very lucky or indeed a freak of nature): Foot blisters. Unsurprising they are one of the most common injuries that occur when running. These sore spots, depending on their size and intensity, are usually so painful that they make normal running virtually impossible.
Clinically termed a friction blister because friction is the primary culprit. Although heat and moisture are contributing factors, friction and the underlying shear forces are what ultimately cause the dreaded blister.
THE BIOLOGY In a nutshell.
As your shoe and sock move against the outer layer of skin (epidermis) which in turn moves against your inner layer of skin (dermis) friction is forming. As the stretching and rubbing between these two skin layers continues, the layers eventually separate. Once this separation occurs, fluid fills the void due to hydrostatic pressure. The result is a fluid sac between the newly separated layers of skin known as a BLISTER.
A hot-spot is a pre-blister state. It’s a warning that your skin is stretching too much and it’s starting to fatigue.
IT’S SUBTLE – It feels warm, like something’s rubbing, and it looks a bit red.
AND IT’S BRIEF – How long does it last? Well might not last 5 minutes. It might not even last 1 minute.
If you feel a sting, you’re too late. That’s the tear under the skin surface that kick-starts blister formation. Within two hours of that stinging sensation, you’ll have a blister.
If you notice while you are running that a blister is forming on your foot, you should probably end your workout early. This is the only way to keep the blister from getting worse or even infected. Plus, if it hurts to put weight on your foot, this will affect your running style and can potentially lead to painful compensation patterns.
If blisters appear during a race or a running event, there is only one thing you can do: grin and bear it!
If you can, let a medic tape the sore spots to help reduce the rubbing.
After you finish running, the first thing you should do is take a rest and let your foot recover. This gives your skin time to heal and doesn’t make the wound worse.
If you have decided to puncture the blister (usually based on the size) make sure you have disinfected the surrounding area thoroughly beforehand, use a sterile needle and cover immediately with a clean patch.
We don’t recommend the ‘threading’ approach for a number of reasons related to infection risk.
Lancing a blister opens it up to infection so it should only be done if appropriate equipment is on hand. If in doubt, do not lance it.
PREVENTION IS BETTER THAN CURE
Of course, the best thing is to prevent blisters before they form.
- Wear properly fitted running shoes. To keep your toes from rubbing, there should be a thumb’s width of space between your longest toe and the toe box. This ensures that your foot has enough room to move on downhill sections and allows room for swelling on longer runs.
- Break in your running shoes and wear them around during the day a few times before you start training in them.
- Change your running shoes regularly. Painful hotspots often depend on the characteristics of the shoe. Changing running shoes frequently allows these sensitive spots to recover faster.
- If poor workmanship on the inside of your shoe is the cause of the rubbing, it often helps to tape this area.
- Keep your feet as dry as possible. Socks made of synthetic fibers wick moisture away from the skin of your feet. Thus, your feet remain dry and it is harder for blisters to form.
- Your feet have to work hard when you run. For this reason, you need to take proper care of them. Regular foot care with the podiatrist helps keep the skin supple and prevents hot spots from forming.