[CALCULATOR]
Protein, fat and carbs, with the endurance work counted.
[WHAT THIS DOES]
Protein is set from bodyweight, fat as a share of calories with a floor, and carbohydrate takes whatever is left. That ordering matters for a hybrid athlete: it means the carbohydrate number rises automatically on a week with more endurance volume, which is exactly the macro that should move.
The order the three macros get set in
Protein first, from bodyweight. Fat second, as a share of calories with a hard floor. Carbohydrate last, as whatever is left.
That order is not arbitrary, and for a hybrid athlete it is the whole point. Carbohydrate is the macro that should move when training moves. Protein requirements barely change with endurance volume; fat requirements are driven by hormonal function and vitamin absorption, not by training. Fuel does change, enormously. Setting carbs as the remainder means a week with an extra 20 miles of running automatically produces a higher carbohydrate number, without you re-running any calculation.
Fix carbs at a percentage instead, and adding a long run silently takes the extra calories out of protein and fat too — which is the opposite of what you want.
Protein: 1.0 g per pound, and why that is the top of the range
Morton et al. 2018 — 49 randomised controlled trials, 1,863 subjects — found the breakpoint for resistance-training adaptations at 1.62 g/kg/day, with the confidence interval extending to 2.2 g/kg. One gram per pound is 2.2 g/kg: the top of that interval, on purpose.
Three reasons to sit at the top rather than the middle:
- The effect is enhanced by prior training experience, and the analysis pooled trained and untrained subjects.
- Re-analyses since 2024 argue the 1.6 figure is underpowered at the upper end.
- In a surplus, protein is not competing with anything. The calories are available. There is no cost.
On a deficit the figure goes up, not down — 1.1 g/lb — because protein is doing a second job there: protecting lean mass while energy is scarce, and providing satiety when you are hungry.
Fat: 25% of calories, with a floor
The defensible range is 20–25% of calories. Below roughly 0.3 g per pound of bodyweight you start compromising hormonal function and the absorption of fat-soluble vitamins, which is why the floor exists and why it binds on aggressive deficits before the percentage does.
Distribution matters as much as the total
The same 180 grams of protein produces a different result across two meals than across four. Roughly 25 to 35 grams of quality protein clears the leucine threshold that maximally triggers muscle protein synthesis, and the response to a meal lasts two to two and a half hours. ISSN guidance is 0.4 to 0.55 g/kg per meal across three to five meals.
For a hybrid athlete there is a second distribution question the pure lifter does not face: carbohydrate timing around the endurance session. A long run on low glycogen is a run that costs more recovery for the same adaptation, and a hard lifting session on the same day is worse still.
| Session | Carbohydrate before | Why |
|---|---|---|
| Easy run under 60 min | Not necessary | Glycogen is not the limiter |
| Long run or ride over 90 min | 1–2 g/kg, 2–3 h before | Glycogen depletion is the limiter |
| Threshold or interval session | 1–2 g/kg | Glycolytic work needs glucose available |
| Lifting after endurance | As much as tolerable between | This is the session most often ruined |
What to do next
Set these numbers, then hold protein and fat constant and let carbohydrate absorb the week-to-week change in training. If you find yourself dropping protein to make the calories fit on a heavy endurance week, the calorie target is wrong, not the protein.
Questions
How much protein does a hybrid athlete need?
About 1.0 gram per pound of bodyweight, or 2.2 g/kg — the top of the confidence interval from Morton et al. 2018, which put the breakpoint at 1.62 g/kg with the interval extending to 2.2. On a deficit raise it to 1.1 g/lb, because protein is then also protecting lean mass and providing satiety.
Do endurance athletes need more carbs than lifters?
Yes, and by a lot. A lifter can train well on 3 g/kg; an athlete running 40 miles a week may need 6 to 8 g/kg on hard days. The practical fix is not a higher fixed carb number but setting carbohydrate as the remainder after protein and fat, so it rises automatically when training volume does.
Should I eat differently on training days and rest days?
Carbohydrate periodisation — more carbs on hard days, fewer on easy ones, with protein and fat held constant — is well supported and easy to run once you have day templates. It is not mandatory. Total weekly intake matters more than its distribution across days.
Can I build muscle and improve endurance on the same calories?
Only at maintenance or a small surplus, and only slowly. Muscle gain requires spare energy; endurance improvement does not require a deficit but is hampered by a large one. The workable zone is maintenance to about +250 kcal, which is small enough that an uncounted long run can erase it entirely.