Macro Calculator for Runners
Macros for runners: carbohydrates as main fuel and protein for muscle recovery.
What macros does a runner need?
Running is an aerobic endurance sport where carbohydrates are the predominant energy substrate at medium-to-high intensities. A runner training 40–60 km/week needs 5–7 g of carbohydrates per kg of bodyweight [¹]. Protein, though less prominent than in strength sports, is key for repairing impact-induced muscle microdamage — 1.4–1.7 g/kg/day is recommended [²]. Fat completes the energy supply, especially during long low-intensity efforts where it represents up to 60% of caloric expenditure.
How to use this calculator
Select 'Active' if you run 4–5 days per week. For high-load weeks (>60 km) or long run days, add 200–400 extra kcal primarily from carbohydrates. The week before a race (tapering), reduce volume but maintain carbs — even increase them 2–3 days before (carb loading: 8–10 g/kg/day).
Macro needs by weekly running volume
| Weekly volume | Carbs (g/kg/day) | Protein (g/kg/day) | Fat (% kcal) |
|---|---|---|---|
| <30 km/week | 3–5 | 1.4–1.6 | 25–30% |
| 30–60 km/week | 5–7 | 1.5–1.7 | 20–25% |
| >60 km/week | 6–8 | 1.6–1.8 | 20–22% |
| Carb loading (2–3 days pre-race) | 8–10 | 1.4 | 15–18% |
FAQ
1What to eat before a long race?
3–4 hours before: high-carb, low-GI meal (pasta, rice, oats) + moderate protein. 30–60 min before: simple carbs (banana, gel, isotonic drink) without fat or fibre to avoid GI issues [¹].
2How often to fuel during a marathon?
Every 30–45 minutes from km 15–20: 30–60 g carbs/hour in gels, drinks or dates. Ultra-distances: up to 90 g/hour with multiple transporters (glucose + fructose) [¹].
3Do runners need more protein than thought?
Yes. Impact muscle damage in running is significant — 1.6 g/kg/day is a reasonable minimum, with additional benefit up to 1.8–2.0 g/kg for runners with body composition goals [²].
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