The Filthy 50 is 50 miles with about 2,000 feet of climbing on rolling roads that are mostly gravel with some dirt, through northern Minnesota’s lakes country in early October. Expect fall conditions in the 40s to 60s with a chance of rain.

This is a twelve-week plan for riders who can already put in long weekend rides but haven’t built specifically toward fifty miles of rolling gravel. Most of the work sits in that seven-to-eleven-hour band, aimed at steady time on gravel and rolling roads, because the demand here is repeated climbing over the distance rather than any single hard effort.

WHAT'S INSIDE

• Structured workouts on your calendar, with real power and heart-rate graphs


• Strength work built in, with video walkthroughs


• Weekly notes from me, plus the Gravel Grit mental program


• A testing week and a mid-plan retest, so the plan runs on your real numbers


• The full Filthy 50 guide — terrain, gearing, fueling