100 mile mountain bike races - the gold standard for ultra endurance racing. These events take more then just riding long hour, they take dedication, preparation and skills work .
This training plan will help get you ready to tackle this iconic distance through heart-rate based workouts, stacked long rides and focused cross training. The weekday workouts are short and focused to allow you to complete them either before or after work, while the weekends have one long workout and one long ride to build on cumulative fatigue.
You should be comfortable riding 4 to 5 days per week prior to starting this plan with an average weekly volume of 8-10 hours. This plan stays at 5 days per week of riding, building up to 14 hours per week. There is one rest day per week and one cross training day. The workouts are built around HR, so check out the power based version if you have a power meter!

Structured Workouts are based off of Threshold Heart Rate, all other rides should be focused on either skills, pacing or riding without having to constantly stare at monitors.