This seven-week plan, developed by the experts at Runner's World, will help you transition from running three miles or 30 minutes to one hour. This plan will help you develop the endurance to run six miles without walk breaks and build the strength to race a 5K (3.1 miles) or finish a 10K (6.2 miles). The plan includes some hills and loosely structured speedwork (fartleks) to help build your strength. Before doing this plan, you should have spent six weeks running regularly for about 30 minutes. The plan includes four workouts per week with an optional fifth day. The first workout is a one-mile run, and the plan builds gradually, so that by the end of the program you should be able to run six miles (or 6.2 miles, a 10K). If you have a BMI of more than 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 an eight-, 10-, or 12-week plan.