Build a carbohydrate, fluid, and electrolyte schedule from body weight, pace, temperature, and humidity, based on endurance fueling guidelines and sweat-rate categories.
Personal + Environment Settings
Body weight (kg)
Race distance (km)
Target pace (mm:ss/km)
Environment
°C
%
Sweat profile
Carbohydrate strategy
90 g/h: race-level mainstream; use glucose + fructose around 2:1.
Expected finish
03:52:06
Sweat rate
1.0 L/h
Total fluid need
2901 ml
Total carbohydrate need
348 g
Fueling Schedule
| Time | Position | Fluid | Carbs | Note |
|---|---|---|---|---|
| T-3 h | 3 hours before race | 500 ml | 98 g | Carb-focused breakfast: toast, honey, banana; avoid new foods. |
| T-30 min | End of warm-up | 200 ml | 30 g | Gel + 100 ml water; avoid bloating from too much sports drink. |
| 25:00 | ~4.5 km | 313 ml | 38 g | Hydrate at aid station |
| 50:00 | ~9.1 km | 313 ml | 38 g | Hydrate at aid station |
| 01:15:00 | ~13.6 km | 313 ml | 38 g | Hydrate at aid station |
| 01:40:00 | ~18.2 km | 313 ml | 38 g | Hydrate at aid station |
| 02:05:00 | ~22.7 km | 313 ml | 38 g | Hydrate at aid station |
| 02:30:00 | ~27.3 km | 313 ml | 38 g | Hydrate at aid station |
| 02:55:00 | ~31.8 km | 313 ml | 38 g | Hydrate at aid station |
| 03:20:00 | ~36.4 km | 313 ml | 38 g | Hydrate at aid station |
| 03:45:00 | ~40.9 km | 313 ml | 38 g | Hydrate at aid station |
| T+30 min | Within 30 minutes after finish | 500 ml | 65 g | 4:1 carb-to-protein recovery plus fluid replacement. |
Product Conversion (per-hour reference)
For a 90 g/h target:
- Energy gel (25 g carbs): 4 packets/hour
- Sports drink (500 ml = 30 g carbs): 1500 ml/hour
- Energy bar (40 g carbs): 2.3 bars/hour
- Chews (4 pieces = 24 g carbs): 15 pieces/hour
Mix glucose:fructose around 2:1 to use two intestinal transport pathways and move practical intake toward 90 g/h.
Sodium / Electrolyte Need
Sodium per hour: 280 mg (heavy sweaters in heat may approach 1500 mg/h)
Total: 1083 mg
Many sports drinks contain about 200-500 mg Na/L; salt tablets often provide 200-400 mg each.
Total: 1083 mg
Many sports drinks contain about 200-500 mg Na/L; salt tablets often provide 200-400 mg each.
Gut Training
To reach 90-120 g/h on race day, you need to train it first. Start near 30 g/h, add about 15 g/h every 2 weeks, and build at least 6 weeks of tolerance.
Scientific Basis
- Stellingwerff & Cox (2014): multiple-transportable carbohydrate strategies around 30-90 g/h are mainstream for endurance fueling.
- Costa et al. (2024): ultra-distance guidelines point toward 90 g/h for efforts over 2.5 hours; newer work suggests some elite women may need more.
- Viribay et al. (2020): compared 60/90/120 g/h and reported better neuromuscular recovery in the 120 g group.
- Sawka et al. (2007): ACSM Position Stand summarizes fluid ranges and sodium considerations for endurance athletes.
- Spriet (2014, Sports Med): caffeine around 3-6 mg/kg before endurance events is commonly effective; split in-race doses can also help.
Caffeine practice: for a 65 kg runner, 195-390 mg about 60 minutes before racing is the classic range. Add a smaller dose around 25-30K only if you have tested tolerance.
Next: Complete Fueling + Race Prep Tools