There are two important elements to preventing blisters in long distance running:
- Running shoes: make sure your shoes are the right fit for your feet. You don't want them to be a tight fit. Running shoes are generally 0.5-1 size larger than your regular shoes.
- Running socks: Don't settle for the standard white, cotton socks. A pair of running socks has a left and a right sock, so a perfect fit for both your feet rather than socks that can be worn at either feet. In addition to this the socks are moisture repellent.
Having the right running shoes and running socks will help reduce friction and build-up of moisture in your shoes and should reduce the possibility of blisters.