Over the years I have taken part in a number of marathon events. Although I am not prone to blisters (losing toe nails is my problem), a number of my friends are. Below you will find some useful information on hydration and blister prevention/ treatment, written by my husband Clive Lathey MSc Sports Medicine. Hydration Dehydration impairs performance and health. Fluid loss during exercise dependent on exercise duration, intensity, temperature and humidity. Body size and fitness levels also affect loss. Pale to very pale yellow urine is an indication of good hydration. Dark yellow urine indicates advanced dehydration. Always start exercise well hydrated. Continue drinking at regular intervals- ideally every 15mins. The aim is to match intake of fluid with the amount of fluid lost. Exercise- more intense or lasting longer than 1 hour- solutions sodium + carbohydrate (Sports drinks), can speed up water absorption and provide additional fuel. Blisters Prevention Always dry your feet; pa