Ironman Training Plan
A 20-week full-distance Ironman buildup with a deep indoor cycling foundation, since the 180km bike leg is the single longest segment of race day.
The bike leg of a full Ironman takes most riders 5–7 hours — longer than the swim and run combined — so this 20-week plan puts serious structure behind your cycling, building from a deep aerobic base through sweet spot work into long, race-pace endurance rides that prepare your legs to still run a marathon afterward.
This plan is dynamic
Every cycling session in this plan automatically scales its power targets to your FTP, so it adapts as you get fitter — no need to guess your numbers or redo the math yourself. Life happens too: drag any session to a different day on your calendar whenever your routine changes.
Week-by-week breakdown
Base
Weeks 1–6Building a deep aerobic foundation on the bike alongside your swim and run training.
Build
Weeks 7–13Sweet spot cycling intervals and long endurance rides to build sustained race-day power.
Peak Endurance
Weeks 14–18Your longest, highest-volume rides, including threshold work to hold pace under fatigue.
Taper
Weeks 19–20Two easy weeks of recovery cycling to arrive at race day with fresh, capable legs.
Frequently asked questions
Why does this plan run 20 weeks instead of the usual 12?
A full Ironman demands a much deeper aerobic base than shorter triathlon distances — 20 weeks gives your body the time it needs to build that volume safely.
How long are the longest bike sessions in this plan?
The plan peaks with rides in the 4–5 hour range, enough time in the saddle to build genuine race-day confidence.