Blisters will, at some point, afflict most runners. They are not pleasant, they can lead to a decrease in performance and efficiency and, if poorly looked after, are an amazing vehicle for infection. The discomfort of running with a blister and the resulting antalgic gait that we adopt, i.e. changing the way we run because of blisters, can lead to dysfunction and a higher potential for injury. Let’s explore some causes of blisters and some strategies to prevent and treat.
I would suggest strongly that the main cause of blisters when we run is friction, when there is some point of irritation between the foot and shoe. This can be caused by the following:
- A foreign body, be it grit or sand between the sock and the shoe,
- Ill fitting or loose socks,
- Prolonged exposure to moisture,
- Shoes and inner soles that are ill fitting, i.e. too loose or tight in terms of length, width and volume. I would add shoes that do not move with your feet,
- Toenails. Keep them in check. Cut straight across, not rounded, keep some length, but not very long or short, and keep them clean. Be mindful of dirt building up or any signs of infection,
- Poor Technique. The nicest, fanciest shoes and socks in the world will not save you if you have poor technique. Landing in front of your centre of gravity (particularly when running downhill), flicking the toe off the ground rather than driving the knee forward and corkscrewing the foot into the ground at the ball. Unfortunately, these are typically not mutually exclusive of the shape and functionality of the shoe.
- Poorly adapted or soft feet. Your feet should be the leanest and toughest part of your body. They need exposure to air, differing temperatures & surfaces and need to be conditioned to be tough. If you spend over 100 hours a week with your feet in sensory deprivation tanks, you should not be surprised if the skin breaks down with multiple hours of running. Think of a toddler’s palm vs that of a stonemasons.
This list seems obvious, and the solutions to the issues that I’ve listed seem even more self evident. However, I am continually surprised at the amount of people who finish a run - be that a training run or an event - with blisters, who tell me that; “I noticed it forming early in the run, but just ran through it”. Most often these are the same people who are bemoaning a less than stellar result due to the pain and discomfort of severe blistering, which has no doubt impacted on their event experience and the time in which they were able to complete the event.
The most useful strategy for preventing blisters is to notice the early warning signs of irritation or pain, commonly described as a “Hot Spot.” Think of this hot spot as a pre-blister alarm that lets you know that it is time to stop and assess what is happening. I would wager that the five or so minutes you spend assessing/treating early on will save you hours of painful, slow running later in the day, and potentially weeks of hindered recovery or ongoing dysfunction caused by having to change your gait to accommodate the blister discomfort.
Hot Spot Treatment
Take your sock off, and check out the affected area. Grit there? Remove it. Wipe and dry as best you can. Some sock irritation? Turn them inside out (which sounds funny but works). If you are on a trail run, use some some tape or a plaster to put a barrier between your skin and provide extra protection. Re-adjust your shoes. Laces too tight or loose? Tongue in place properly? There are multiple different ways of lacing your shoes to alleviate pressure on the top of the foot or to better capture the heel. Do some homework and experiment with what works best for you.
Preparation for Prevention
As I said above, an excellent preventative for blisters is preparing your feet. Being in bare feet is good for you on many levels. Having skin on our feet that is healthy and robust will go a long way to preventing blistering. Our feet are extraordinarily sensitive, they are what connects us to the earth and one of the major sources of neural feedback. Take care of them by letting them do what they are designed to do, that is, engage with the environment.
In terms of racing or events, again, preparation is key. Use your training to experiment on the shoe and sock combo that works for you, although again, I would hazard that a shoe that is as flexible and as low to the ground as you can accommodate, and is actually foot shaped, is a good start. The adage of “nothing new on race day” is especially germane here. However, I would also caution that keeping an eye on the repair of our footwear is useful too. Having multiple pairs of socks and shoes that work for you is an investment that will pay dividends in the long term.
To, or Not To,...Pop.
As always, we come to the age old question with blisters, to pop or not to pop. As ultimately satisfying as this is, it is best to leave the blister alone if it is not causing you any pain or undue distress. The fluid will eventually reabsorb, the skin over the top of the blister will die off and new cells will form underneath. This process does take time. I understand in events like The Marathon Des Sables or the Jungle Marathon, two multi day events with all the grit and moisture you can handle, rapid blister treatment is administered by means of a “Hot Shot”. This technique, used by the US Army, entails the blister being drained and a tincture of Benzoin injected into the blister to essentially glue the blister back to the skin. The tincture serves as an antiseptic and the treatment is known to be rapid, effective, and extremely painful (hence the name “Hot Shot”).
Hopefully, most of us can get through our lives without needing a hot shot, or some such treatment, however If there is considerable pain or dysfunction, then draining the fluid from the blister may be required. This process needs to be as aseptic as possible to reduce the potential for infection. Place a small hole with a needle at the edge of the blister, drain, dry and cover with a clean dressing. Material or dirt getting into the blister and the immature skin is an ideal medium for infection. Simple blisters have been known to turn rapidly into cellulitis if not taken care of. This is especially common with blisters that have been “deroofed” or the top skin has come away. If this has happened, keep the area clean and moist, and check regularly for signs of infection.
As with most running related issues, with blisters prevention is 99 percent of the cure. A considered, careful assessment of the foot as early as you notice distress or irritation is a sure fire way to maximise your enjoyment when running and to avoid hours of pain and discomfort.
As always, I’d love to hear from you regarding your experiences with blisters, what has worked, and what hasn’t.