Podiatrist Rob Dallimore writes: Blisters are considered to be one of the most common sporting injuries. No one seems immune to them and they can often strike when least expected - at times putting an end to what could be a good race. However, we all have our own little remedies and prevention/good luck rituals which each of us say is the best one (although, they never seem to work for anybody else). Now I'm going to give my 2 cents worth.

A blister is a direct result of a combination of friction and an excessively moist environment, which may cause a separation between the epidermis and the dermis (layers of the skin). As a response to this, fluid will enter the site and increase the pressure in the area, thus resulting in the blister. If blood vessels are damaged from the friction this will develop into a blood blister and that is when it can get messy and potentially dangerous.

It is common for endurance runners to develop blisters over the course of a race such as a marathon, but to rarely have them during training - I can imagine you all nodding your heads now. The reason for this is that in a race situation you often perspire more and are pouring gallons of water over your body during the event. This fluid eventually flows down into your shoes and forms nice puddles around your toes - combining this with the associated friction from a higher pace may be sufficient to form blisters. Blisters do develop in other parts of the body but don't ask me to look at them for you. I only look at feet.

Question: What is the best way to prevent blisters?
Answer: Stop every 10km, shower, dry your feet and shoes, and put on a new pair of socks.

Ok, so maybe it isn't practical to expect this recommendation to catch on, although imagine having a drink station, port-a-loo and shower all in one. So what are the alternatives?

Prevention is the key to this problem, and it is no use waiting for race day to see whether those new shoes are going to cause blisters. It's all very good for me to tell you what works and what doesn't, but it should become a personal thing for each individual. Try different techniques until you find a perfect combination. But, by all means read on, I feel I can offer some good advice.

• Be particular about what shoes you should run in. There are many different brands, models and shapes in the market - some expert advice can steer you in the right direction. Avoid shoes that impinge on your toes from the sides and tops, those shoes are bound to cause some problems. Some shoes also have a higher ankle and heel counter, again a potential blister trap. Also shoes that have an extremely high instep can be a cause for blistering.
• Don't be a slave to fashionable socks only, if they have a sports label on them it doesn't always mean they are what the athletes wear. Choose ones that are designed to wick moisture away from the foot. Avoid cotton ones as these have a tendency to absorb moisture and when dry will turn into 180 grit sandpaper.
• Try to keep your feet dry. However, don't take a 10 minute detour around a puddle if everyone else is going straight through the middle.
• Some people swear by Vaseline. This makes me cringe when I imagine gooey and highly lubricated toes ramming into the front of a show as you pound down a hill. I've seen the results and it's not always pretty. But as I say, each to his own, I'm sure for some people it is the magic solution, not me though.
• And I've said it before, but I'll say it again: Put those flash 1 week old running shoes back in the closet until they have a decent amount of wear in them. The old favorites will probably be the better option.
• A regular foot inspection by yourself or a partner should identify any potential blister sites, as would general training runs. I bet you're all jumping at the chance to perform a foot examination right now.
• Regular application of a drying agent to the skin, such as methylated spirits to at-risk sites is a good option. However I would avoid doing this to existing blisters, especially open ones!!!

So the next controversial issue is what to do with the blister once it is there. This depends largely on the size of the lesion, the mechanism of its development and whom you talk to. The thing to be aware of is that if the blister remains intact and there is no fluid seeping out then it is technically a sterile lesion and if possible it should remain intact. This is all very easy to do if it is not in a high weight bearing/stress area and if the lesion is small. If, however the blister is large and somewhere prominent such as the heel or the side of the little toe then it is not desirable to leave it intact. This is due to the amount of friction it would be exposed to and the pressure applied to it, especially if it is a large one.

In cases such as this I recommend lancing the side of the blister with a clean/sterile needle and squeezing gently to remove the fluid. The roof of the blister should remain as this provides the best environment for healing. An antiseptic dressing should be applied and ensured that it will not shift once the foot is back in shoes. The dressing should be changed daily or more often if necessary. If the blister has already burst then the same dressing principle should be adhered to. Extra care should be taken with blood blisters as there is a greater risk of severe infection, look for pus and streaking. Always be aware of the cardinal signs of inflammation - redness, heat, swelling, and pain.

If at all concerned, contact your Podiatrist or General Practitioner.

At Foot Traffic Sports and General Podiatry we see footwear as a crucial part of the treatment regime. You do not need to have a referral to come to Foot Traffic, you are more than welcome to visit us for advice prior to buying your shoes. An appointment with Foot Traffic can be made by calling 09 5215577, or emailing info@foottraffic.co.nz . For further information also visit www.foottraffic.co.nz. Clients of EnduranceCoach.com will qualify for a discount on their initial consultation.