The Build in Numbers
May through September 2025 — five months of preparation for Ironman Italy Emilia-Romagna in Cervia. No external coach, no off-the-shelf plan: just a spreadsheet, a power meter, and a stubbornness that some might call pathological.
Twenty thousand TSS in twenty weeks. An average of 1,018 TSS/week, with a progression that started at 804 and peaked at 1,647 in the biggest week. Not linear, not clean, but real.
Weekly TSS Progression
The backbone of any Ironman build is the load progression. Here are the 21 weeks of build, deloads included:
Monthly Breakdown
| Month | Sessions | Km | Hours | TSS |
|---|---|---|---|---|
| May | 44 | 1,594 | 78h | 3,648 |
| June | 37 | 1,296 | 72h | 3,554 |
| July | 39 | 1,439 | 81h | 4,052 |
| August | 48 | 2,080 | 108h | 6,151 |
| September | 34 | 1,112 | 54h | 2,956 |
| Total | 202 | 7,520 | 393h | 20,361 |
August was the month of truth: 48 sessions, 2,080km, 108 hours, 6,151 TSS. Nearly a third of the total load packed into a single month. The hours-to-TSS ratio in August (57 TSS/h) tells you it wasn't just volume — it was high-intensity volume.
Key Workouts
The Long Rides
Three rides built the confidence needed for 180km on race day:
- Gavia-Tirano — 192.8km, 7h24', 3,174m D+, 493 TSS. The hardest workout of the entire build. Passo Gavia with temperatures below 10°C on the descent.
- Crocedomini — 150.9km, 6h07', 3,048m D+, 457 TSS. A long, steady climb — perfect for practicing effort management.
- Manghen-Rolle — 157.6km, 6h19', 3,895m D+, 433 TSS. Nearly 4,000 meters of elevation gain: the ultimate leg test.
Brick Sessions
Brick = bike + run with no break. They simulate the T2 transition and teach your body to run on tired legs.
- September 6 — 144km bike + 16km run = 433 TSS. The last brick before race day.
- August 9 — 126km bike + 15.5km run = 500 TSS. The heaviest brick of the build.
The Long Run
Bionic Marathon, July 20 — 42.2km in 3h13', TSS 190. A prep marathon run at controlled pace (4:34/km) to test muscular endurance beyond 30km.
Race Day: September 20, 2025
Ironman Italy Emilia-Romagna, Cervia. Start at 6:55 AM. Here's how it went.
Swim — 3.87km
Avg HR 114 bpm
TSS 41
Bike — 178.6km
Avg HR 129 bpm
TSS 235
Flat tire at 55 km/h, km 136
Run — 40.9km
Avg HR 136 bpm
TSS 180 · 4:46/km
Stomach in crisis from km 15
Total
463 TSS race total
Overall avg HR ~128 bpm
Bike Speed Profile — The Flat Tire Effect
The chart below shows average speed per 10km segment on the bike leg. The drop after km 136 is sharp and permanent.
Average speed per 10km segment (km/h). The ⚡ marker indicates the flat tire at km 136.
The Marathon
The first 15km went according to plan: 4:30-4:40/km, HR under control, nutrition on track. Then the stomach said enough. From km 15 to km 30 it was pure damage control — walking through aid stations, small sips of cola, no gels. The final 10km were mechanical running: legs moving on inertia, brain counting down the remaining kilometers.
Final average: 4:46/km. Far from the 4:30 target, but given the GI situation, it's an honest result.
What Worked
- High bike volume with real elevation — Mountain rides built a resilience that flat roads simply can't deliver.
- Regular brick sessions — Two per month from July onward. The T2 transition on race day was a non-issue.
- Aggressive deloads — Week 6 at 139 TSS and the final taper made sure I arrived at the start line with fresh legs.
- Non-linear TSS progression — Peaks followed by lighter weeks. The body needs time to absorb.
What I'd Do Differently
- Race nutrition — 90g/h of carbs wasn't enough for the conditions (heat, humidity). I should have tested 100-110g/h in training.
- More long runs beyond 30km — A single prep marathon isn't enough. I needed at least two sessions of 32-35km at race pace.
- More consistent swimming — Swimming was the forgotten child of this build. Two sessions per week aren't enough for an efficient 3.8km.
Full Analysis: TSS vs Performance
How does training load translate into race day performance? The detailed data analysis shows a strong correlation between brick session volume and marathon performance. The run's TSS/km ratio on race day (4.4 TSS/km) was in line with the longest bricks, suggesting the body was genuinely prepared — the problem was gastrointestinal, not muscular.
CTL at race day: 142, TSB: +15. TSS distribution: swim 9%, bike 51%, run 39%.
Key Workouts of the Build
Epilogue: The Collarbone, 6 Months Later
That's the part no TSS chart captures. Ironman prep builds an athlete who feels invincible — the volume hardens you, fatigue becomes routine. Then one second on wet tarmac brings you back to zero.
The hardest lesson didn't come in Cervia. It came in a hospital, staring at an X-ray.
The Numbers Don't Lie
10h52' isn't the time I wanted. But 7,520km, 393 hours, 50km on a flat tire, and a marathon with a stomach in revolt — those are numbers that tell a story bigger than a finish time.
An Ironman isn't a speed race. It's a management race. Next time — when the collarbone allows it — we improve.