Pacing Smart in Ironman Nice 2025: 180 km Bike + Marathon Guide
Ironman Nice 2025 Pacing Plan: 180 km Bike + Marathon on the Promenade
Series “Conquer Nice” • Entry #5
Smart pacing on the 180 km bike + 42 km marathon is the single biggest weapon you have in Nice. Respect the mountains, cap surges, and protect glycogen: you’ll save 3–5% total race time (2024 data, n = 117 finishers).
1 · Why precision pacing is your best weapon
- Minimizes lactate spikes on Col d’Eze and Col de Vence.
- Guarantees glycogen availability for the coastal marathon.
- Translates into fresher legs on the Promenade when it matters most.
2 · Race-day course profile
| Segment | Distance | Elevation | Grade % | Surface |
|---|---|---|---|---|
| Bike 0–20 km | 20 km | 80 m | 0–2% | Coastal flat |
| Bike 20–100 km | 80 km | 1,650 m | 3–11% | Climbs + technical descents |
| Bike 100–160 km | 60 km | 420 m | 1–4% | Crosswind exposed |
| Bike 160–180 km | 20 km | 150 m | Flat | Promenade return |
| Run (4 loops) | 42.2 km | 60 m | 0–1% | Seafront promenade |
Forecast: 27 °C average · 60% humidity → hydration is critical.
3 · Target pacing table
| Finish Goal | Bike Split | NP (W) | IF | Marathon Pace | Total Time |
|---|---|---|---|---|---|
| Sub-10 h | 4 h 50 m | 240–250 | 0.78 | 4:35 / km | ~9 h 55 |
| 10–11 h | 5 h 10 m | 220–230 | 0.75 | 5:05 / km | ~10 h 40 |
| 11–12 h | 5 h 35 m | 200–210 | 0.70 | 5:40 / km | ~11 h 45 |
Masamune Aero Tip: –5 mm stack + 92° elbow angle (CdA 0.23) can save 15–30 W in free watts.
4 · Wattage distribution by section (75 kg)
| Section | Sub-10 h | 10–11 h | 11–12 h |
|---|---|---|---|
| Col d’Eze (km 20–31) | 290–300 W | 250–260 W | 220–230 W |
| False flats (km 40–60) | 240 W | 215 W | 195 W |
| St-Jeannet descent | “Free watts” — stay aero & safe | ||
| Promenade return | 225 W | 200 W | 185 W |
Cadence: 85–95 rpm · Tires: 25 mm → 95 psi.
5 · Marathon strategy (4 × 10.5 km loops)
Each loop includes ~1.4 km of light cobblestones (expect ~+5 s/km penalty).
| Loop | Sub-10 h | 10–11 h | 11–12 h |
|---|---|---|---|
| 1 (km 0–10.5) | 4:30 | 5:00 | 5:35 |
| 2 | +5 s | +10 s | +12 s |
| 3 | +10 s | +15 s | +18 s |
| 4 | Negative split if you saved fuel | Hold steady | Hold steady |
Caffeine: 80–100 mg only after km 21.
6 · Fueling & cooling
- Bike: 90 g CHO/h · 600 mg Na⁺/h · 750 ml fluids/h (if >25 °C).
- Run: 35 g CHO every 20 min + 200 ml water.
- Cold sponge every 40 min (≈ −0.3 °C core temp).
Dial it by weight & climate with the Hydration & Fuel Calculator (PDF).
7 · Downloads
- GPX — Bike 180 km
- GPX — Run 42 km
- Masamune Aero Cockpit + Assembly Video
- Race-Day Checklist • Côte d’Azur (PDF)
- Hydration & Fuel Calculator (PDF)
8 · Internal resources (keep building your plan)
- Ironman Nice 2025 — Course Map & GPX Strategy
- Bay of Angels — Swim Guide
- Col d’Eze — Pacing & Aero Setup
- Nutrition & Hydration — Mediterranean Heat Plan
9 · Bonus: join the community
Join the Tetsuo Performance Strava Club.
“Promenade Cut-off” challenge: upload your best 10.5 km loop before 15 SEP; Top-5 consistent efforts win official Tetsuo merch.
10 · Next step
Load the GPX files, adjust your cockpit, and come back next week for the final entry: Stress-Free Nice — Race Week Checklist.
Pace smart, fuel hard, and let Masamune handle the wind. Redefine Your Limits.
