12 Week Plan to get ready for the Firecracker 50 MTB Race. Plan includes not just on the bike training but off the bike core and strength work, very important to keep you from breaking down in the long race.
The plan progresses from aerobic foundation, to threshold with over/under work, and then into more specific race intensity. That said, the plan will yield the best results for someone that has at least 4-6 weeks of base miles coming into it.
Field test in the second week to establish power and heart rate zones, both devices help but not a necessity!
Good luck, enjoy!