Blisters form as the result of friction. While they are generally formed by new or poorly fitting shoes, due to excessive rubbing on the foot, dampness causes them to form as well. Marathon runners do not have the opportunity to change their shoes during the course of the race, so if their running shoes become wet, they're stuck with them for the entier 26.2 miles. Running socks wick moisture away from the foot, generally aiding in preventing blisters from forming. When the foot, shoe, and sock are all wet, however, they're not able to do so.
When a blister forms it's important to treat them properly. If you're not confident in treating blisters yourself, you should visit your Houston podiatrist to have them painlessly treated. If you do treat them yourself, remember that the inside of a blister is sterile, so you should try and keep the top of the blister, called the roof, intact. Use a sterile needle, or take measures to sterilize one, and puncture the blister in several places. The fluid that is expressed should be entirely clear. If it is cloudy, bloody, or resembles pus, be sure to call our office immediately.
Remember, it is very important to recover after running a marathon. It's a wonderful accomplishment and be sure to take great care of your body, so you can train again for another.