This 12-week training plan requires the use of a heart rate monitor and is designed for the experienced runner who has a solid base of running and is looking to develop better strength endurance during the off season or non-racing season. This plan works great for those 10k to ultra distance runners looking to continue to build fitness and remain "sharp" during non-racing times of year. Following this plan will improve lactate threshold, build strength endurance and foundational leg strength. The workouts included in most weeks allow you to customize the plan to your capacity for weekly volume. with long weekend runs topping out at 2 hours. Workout descriptions are very specific, with a focus on "quality" runs. R&R weeks every fourth week when training is greatly reduced for 4-5 days. These R&R weeks will allow for adaptation and improved performance.