A full marathon is 26.21875 miles and a half marathon is 13.10938 miles. Runners will train for months in prepartion for a marathon. They will run consistently throughout the week 5-9 miles and plan for longer runs on the weekends to ensure they are ready for the race. Many people set up a self challenge to cross participating in this type of event of their list of things they want to accomplish in life. It takes a great deal of focus and dedication to prepare for one of these races.