8 weeks
Intermediate Ironman Program - 8 Weeks
Intermediate Ironman triathlon training plan: 8 weeks, 12 to 20 hours a week, building up to a 6h ride and a 3h run. 3.8 km swim, 180 km bike, 42.2 km run.
Intermediate Ironman plan at a glance
8 weeks · 12-20 h/week · 8-10 sessions
Consistent volume over several months, very long sessions and full rehearsal of the fuelling plan. The plan starts from a 2.5 km swim, a 3h ride and a 1h30 run, and builds to 4 km, 6h and 3h.
How this Ironman plan is built
More than ten hours of effort: fuelling, steady pacing and mindset count as much as fitness.
Long session progression
The long ride grows from 3h to 6h and the longest run from 1h30 to 3h, step by step.
Lighter weeks
One week in 4, volume drops by about a third to absorb the previous weeks of work.
Bricks
From week 3, one bike-run brick a week, up to 5h + 1h.
Intensity
2 quality sessions a week in the build phase; everything else is endurance (Z1-Z2).
Prerequisites and Required Level
To follow this intermediate Ironman plan from week one:
Swim 2.5 km without stopping
Ride 3h at endurance pace
Run 1h30 continuously
Have 12 to 20 hours a week available
Completed at least 1 triathlon
Mastered T1 and T2 transitions
Detailed Training Phases
8 weeks in four phases. Durations are those of the longest sessions at the start and end of each phase.
Base Phase
Weeks 1-2
Settle into consistent volume and a solid aerobic base
Objectives:
- Continuous swim: 2.5 km → 2.6 km
- Long ride: 3h → 3h55
- Longest run: 1h30 → 1h55
Key workouts:
- •1 technique or pace session(s) a week, the rest in Z2
- •Swim: 3 x 400 m steady, 30 s rest
Build Phase
Weeks 3-4
Extend long sessions and train the gut to eat on the bike
Objectives:
- Continuous swim: 2.6 km → 3.4 km
- Long ride: 3h55 → 5h05
- Longest run: 1h55 → 2h35
Key workouts:
- •Swim : 5 x 400 m steady, 30 s rest
- •Bike : 3 x 30 min in Z3, 10 min easy
- •Run : 3 x 15 min at marathon pace, 3 min jog
- •Brick : 3h30 + 40 min
Race-Specific Phase
Weeks 5-6
Rehearse race day: very long sessions and the full fuelling plan
Objectives:
- Continuous swim: 3.4 km → 4 km
- Long ride: 5h05 → 6h
- Longest run: 2h35 → 3h
Key workouts:
- •Swim : 3 x 1000 m at race pace, 1 min rest
- •Bike : long ride with 3 h at race pace and full fuelling
- •Run : long run with 2 x 20 min at marathon pace
- •Brick : 5h + 1h
Taper Phase
Weeks 7-8
A long taper to clear months of fatigue
Objectives:
- Long ride cut to 3h
- Longest run: 1h30
- Last hard session early in week 8
Key workouts:
- •Short reminders: long ride with 3 h at race pace and full fuelling at half volume
- •Open water swim if possible
Detailed Sample Week
Week 4 of 8, in the middle of the build phase: 8 to 10 sessions. Sessions can move to another day, but keep an easy day after the hardest one.
Training zones:
Key Program Workouts
The sessions not to miss, in their intermediate version for an Ironman.
Swimming
Threshold (build)
1x/week5 x 400 m steady, 30 s rest
Builds the continuous swim towards 4 km
Race pace (specific)
1x/week3 x 1000 m at race pace, 1 min rest
Locks in race pace
Cycling
Long ride
1x/weekUp to 6h in Z2
Endurance and fuelling practice
Intensity
1x/week3 x 30 min in Z3, 10 min easy → long ride with 3 h at race pace and full fuelling
Hold race pace on the bike
Running
Long run
1x/weekUp to 3h in Z2
Running endurance
Quality
1x/week3 x 15 min at marathon pace, 3 min jog → long run with 2 x 20 min at marathon pace
Race pace on tired legs
Brick
Bike then run
1x/week from week 35h + 1h at peak
Gets the legs used to running off the bike
Races at this distance
To be ready on race day, start this 8-week plan on the date shown under each race.
Ironman World Championship
Kona, Hawaii, USA — 10 October 2026
Plan start: 15 August 2026
Ironman France Nice
Nice, France — 28 June 2026
Plan start: 3 May 2026
Challenge Roth
Roth, Allemagne — 5 July 2026
Plan start: 10 May 2026
IRONMAN European Championship Frankfurt
Francfort, Allemagne — 28 June 2026
Plan start: 3 May 2026
Embrunman
Embrun, France — 15 August 2026
Plan start: 20 June 2026
IRONMAN Barcelona
Calella, Espagne — 4 October 2026
Plan start: 9 August 2026
IRONMAN Lanzarote
Puerto del Carmen, Espagne — 23 May 2026
Plan start: 28 March 2026
IRONMAN Hamburg
Hambourg, Allemagne — 7 June 2026
Plan start: 12 April 2026
Technique in pictures
Nutrition for an Ironman
An Ironman takes 10h-13h at this level: needs change with the length of the effort.
Rides over 4 hours
Train the gut to take 60 to 90 g of carbohydrate per hour for several hours. It is trained just like the legs.
Race day
Write an hour-by-hour plan: carbohydrate, water and salt. Follow it from the first hour on the bike, before you feel hungry or thirsty.
Marathon
Plan to eat and drink at every aid station. Any product offered on course should have been tested in training.
Equipment for an Ironman
Essentials first; the rest can wait for a second race.
Swim
Essential
- Wetsuit that does not chafe over 3.8 km
Optional
- ○Anti-chafe cream
Bike
Essential
- Position validated on 5-hour rides
- Repair kit
Optional
- ○Tri bike
- ○Power meter to hold your pace
Run
Essential
- Shoes tested on your longest runs
Optional
- ○Gel belt
- ○Special needs bags prepared in advance
Common Mistakes to Avoid
The most frequent mistakes on an Ironman at intermediate level.
Eating too late
Solution: A deficit built on the bike cannot be recovered in the marathon: eat from the first hour.
Stacking heavy weeks without recovery
Solution: Over several months, lighter weeks prevent burnout and injury.
Doing every session at the same intensity
Solution: Easy sessions must stay easy so the quality sessions can be done well.
Frequently Asked Questions
This plan lasts 8 weeks: base in weeks 1-2, build in 3-4, race-specific work in 5-6 and taper in 7-8. It takes 12 to 20 hours a week over 8 to 10 sessions.
At the peak of the race-specific phase: a 4 km continuous swim, a 6h ride, a 3h run and a brick of 5h on the bike followed by 1h of running.
In an average 16-hour week: about 2.5 h of swimming, 9 h of cycling and 5 h of running. For an Ironman, cycling takes the biggest share because it is the longest leg of the race (3.8 km swim, 180 km bike, 42.2 km run).
This plan adds 2 quality sessions a week in the build phase, for example 3 x 30 min in Z3, 10 min easy on the bike and 3 x 15 min at marathon pace, 3 min jog on the run. A time of 10h-13h is common at this level; most of the gain comes from doing those sessions consistently.
Pick the plan up at the current week without making up lost sessions. The plan has a lighter week every 4 weeks: if you missed more than 10 days, repeat the last completed week before moving on.
As a guide: 13h-17h for a first Ironman, 10h-13h at intermediate level, under 10h for the fastest. More than ten hours of effort: fuelling, steady pacing and mindset count as much as fitness.
Three landmarks: elbows bent (90–110°) to absorb shocks and relax the shoulders, knee still bent around 140–150° at the bottom of the pedal stroke (saddle height), stable back angle around 40–45°. Knee or neck pain is a fit problem: have it checked — ±5 mm of saddle height changes everything.
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