Changes

 Most runners should not get blisters. There are those who are running in situations that make blisters very hard to avoid (Badwater - [http://en.wikipedia.org/wiki/Badwater_Ultramarathon), http://en.wikipedia.org/wiki/Badwater_Ultramarathon),Badwater] but for distances of 50 miles or less, blisters should not be an issue. I suffer from a skin condition ("non-Hallopeau-Siemens recessive dystrophic epidermolysis bullosa") called [[Epidermolysis Bullosa]] that makes my skin blister easily, so if I can run 100+ miles without blisters, you should be able to! There are a number of approaches to preventing blisters.

==Changes in foot size==Remember that losing or gaining body fat can change the size of your feet. Shoes that used to fit you perfectly may not longer fit the same.A more acute problem occurs on longer races when the feet swell up. Having spare shoes that are slightly larger, or thinner socks for later in a race can help with this problem. Of course, getting the fit right is hard, as you can't practice this until your feet are swollen, and different situations may produce differing levels of swelling.   ==Calluses== [http://en.wikipedia.org/wiki/Callus Calluses ] are a sign of poor fitfitting shoes. A callus is a spot that is likely to turn into a blister with longer distances. You can file down a callus and keep is moisturized, but that is a symptomatic approach. The key is to fix the underlying problem, which is normally the fit of your shoes. Note that a callus is a spot that is thickening; the general thickening of the skin due to being barefoot does not tend to cause this problem. The key is to watch out for small areas or spots that have excessively thick skin.

== Dehydration & Hyponatremia ==Dehydration can be a contributor to blisters, as the skin loses some of it's tension ([http://www.nlm.nih.gov/medlineplus/ency/imagepages/17223.htm skin turgor]) with significant dehydration. However, reduction in skin turgor is generally associated with 6-9% dehydration (excluding glycogen depletion water losses), at which point the dehydration itself should be more of a problem than the blisters. Hyponatremia is a very dangerous condition. One and one of the symptoms is swelling of the hands and feet, which can cause black toenails or blisters. Read up on [[Practical Hydration]] and [[Hydration 101]].

To reduce friction, you can use a lubricant on your feet. A powder can act as both a lubricant and a drying agent. I like Hydropel, which lubricates and helps prevent the skin absorbing moisture; it's particularly useful in wet conditions. (See <here>.) Blister Shield powder is Teflon, which I found helps a bit, but tends to form clumps when wet. [http://www.zombierunner.com/store/categories/foot_care/powders/ http://www.zombierunner.com/store/categories/foot_care/powders/] and [http://www.zombierunner.com/store/categories/foot_care/lubricants/ http://www] == Maceration ==Maceration occurs when the skin becomes soaked with water. Typically the skin has a wrinkled and pale appearance, and is softened. Maceration is likely to lead to blisters, and can be hard to avoid when running in wet or hot, humid conditions.zombierunnerI've found that Hydropel can help delay maceration; apply liberally before the race starts and spend some time rubbing it into the skin so that is is absorbed.com/store/categories/foot_care/lubricants/]