This 10-week plan was designed by the experts at Runner's World for advanced runners who have averaged 35 miles per week or more for at least six months and who want to develop speed over a longer distance. Each week features one or two days of rest and five or six days of running. That includes race-pace runs, speedwork, and long runs, which start at 10 miles and peak at 13 miles. Not the right plan for you? Check out Runner's World's training plans for beginners and intermediate runners.