This eight-week plan, developed by the experts at Runner's World, will help you develop endurance and introduce you to track workouts to boost your speed and fitness. The plan includes some hills and formal speedwork on the track. Before doing this plan you should be able to run 18 miles per week with a long run of at least 6 miles. Each week includes five workouts with one track workout and one rest day. Each Saturday there will be a long run, which starts at 6 miles at the beginning of the plan and peaks at 9 miles. The first workout is a two-mile run, and the plan builds gradually, so that by the end of the program you should be able to complete a track workout, plus a long run of 8 miles. If you have a BMI of at least 25, are 60 years or older, or if you'd like to take a more gradual approach, you can repeat any week, or every week, and stretch this out to a 10- or 12-week plan.