Actress Vishka Asayesh in the Swiss marathon

For many runners, the desire to do a marathon is about personal challenge. You might want to test your limits or prove that you can go the distance. Perhaps a friend has talked you into it. Maybe you'd like to lose weight, get healthier or raise awareness for a charity.

Whatever your reason, hold on to it and remind yourself of it often during the months that lie ahead. When your legs are tired or the weather is nasty, maintaining your motivation will help you get out the door.