Running Nutrition Guide — What to Eat Before, During and After
Running nutrition is simpler than the supplement industry makes it look, and more important than most runners realise. The food you eat before a run decides whether you feel strong or empty; the food you eat during a long run decides whether you finish or hit the wall; and the food you eat after a run decides how quickly you recover for the next one.
This guide covers all three: what to eat before, during and after running, how much carbohydrate you need, how protein fits in, and how hydration works — with practical meals, not abstract advice. It is written for runners from 5K to marathon, because the principles are the same and only the quantities change.
Use the calculator
Start with your own numbers: try our calorie calculator, meal calorie calculator to work out your figures before applying anything on this page. The worked examples below use round numbers so you can follow the maths; the calculators use your real weight, height, age and goal.
Related reading: Running in the Heat — Hydration, Pacing and Safety, Marathon Training Guide — 16-Week Plan, Pacing and Fuelling, What to Eat Before a Workout — Timing and Food Choices. You can also browse the full guides section for the rest of the series.
The key points
Before: eat carbohydrate, 2–3 hours ahead, and keep it familiar. A pre-run meal should be rich in carbohydrate, low in fat and fibre (which slow digestion), and something you have eaten before — toast with jam, porridge with banana, rice with chicken. Eat 2–3 hours before a long run, or 1–2 hours before a short one; a small snack (a banana, a slice of toast) 30–60 minutes before is fine if you need it. Never try a new food on race day.
During: carbohydrate for runs over 90 minutes, water throughout. The body stores about 2,000 kcal of glycogen — enough for roughly 30 km — so runs under 90 minutes need no fuelling beyond water. Longer runs need 30–60 g of carbohydrate per hour from gels, chews or sports drinks, starting in the first hour, plus water at regular intervals. The gut needs training: practise the exact products on long runs, because a new gel on race day is a gamble with your stomach.
After: carbohydrate plus protein, within a couple of hours. The post-run meal should replace glycogen (carbohydrate, 1–1.2 g/kg in the first hours) and support muscle repair (protein, 20–40 g). A meal of chicken and rice, or eggs on toast with fruit, covers both — and chocolate milk, famously, is a good recovery drink because it contains carbohydrate and protein in a useful ratio. The "30-minute window" is less urgent than once believed, but eating within a couple of hours is still sensible.
Daily carbohydrate needs depend on mileage. A runner doing 30–50 km a week needs about 5–7 g/kg of carbohydrate a day; a marathoner doing 80+ km needs 7–10 g/kg. At 75 kg, that is 375–525 g a day for the moderate runner — a lot of food, and the reason runners eat so much pasta and rice. Low-carbohydrate diets and high-mileage running are a poor combination: the glycogen stores never fill, the runs feel flat, and recovery suffers.
Protein for runners is 1.2–1.6 g/kg a day. Runners need less protein than lifters — the damage is different — but they still need more than sedentary people: 1.2–1.6 g/kg a day, spread across meals, with 20–40 g after a hard or long run. At 75 kg that is 90–120 g a day. Protein after running supports repair; protein before running is less important than carbohydrate, because the run's fuel is glycogen, not amino acids.
Hydration is a daily habit, not a race-day fix. Drink to thirst through the day, keep urine pale yellow, and do not overdrink before a run — a litre of water an hour before the start will just need a toilet stop. During runs over an hour, drink 400–800 ml per hour to a plan, with electrolytes for runs over 90 minutes. After the run, drink to thirst and eat normally; the salt in food replaces what sweat removed, and sports drinks are only needed for long, sweaty sessions.
At a glance
| When | What to eat/drink | How much | Example |
|---|---|---|---|
| 2–3 hours before | Carbohydrate, low fat/fibre | Normal meal | Porridge + banana; toast + jam |
| 30–60 min before | Small carbohydrate snack | 100–200 kcal | Banana; slice of toast |
| During (< 90 min) | Water only | To thirst | Water |
| During (> 90 min) | Carbohydrate + water | 30–60 g carbs/hour | Gels, chews, sports drink |
| Within 2 hours after | Carbohydrate + protein | 1–1.2 g/kg carbs; 20–40 g protein | Chicken + rice; eggs on toast |
| Daily (30–50 km/week) | Carbohydrate | 5–7 g/kg/day | Rice, pasta, oats, bread, fruit |
| Daily protein | Protein | 1.2–1.6 g/kg/day | Meat, fish, eggs, dairy, beans |
The quantities scale with body weight and mileage — use the formulas below with your own numbers rather than copying the examples.
The formula behind it
The carbohydrate maths uses body weight: daily carbohydrate = 5–7 g/kg for moderate mileage (30–50 km a week), and 7–10 g/kg for high mileage (80+ km). A 75 kg runner at 5–7 g/kg needs 375–525 g of carbohydrate a day — which is 1,500–2,100 kcal from carbohydrate alone, or about 300–400 g of cooked rice (roughly 3–4 cups). A 60 kg runner at the same rate needs 300–420 g a day.
The during-run maths is 30–60 g of carbohydrate per hour: a gel contains about 20–25 g, so one gel every 30–45 minutes covers it, or a sports drink at 6–8% carbohydrate provides about 30–40 g per 500 ml. The post-run maths is 1–1.2 g/kg of carbohydrate in the first hours plus 20–40 g of protein: a 75 kg runner needs about 75–90 g of carbohydrate (a large plate of rice or pasta) and 25–35 g of protein (a chicken breast, or three eggs) in the recovery meal. The total calorie maths comes from Mifflin-St Jeor (Mifflin et al., 1990) plus activity: a 30-year-old man, 75 kg, 180 cm, very active has a BMR of 750 + 1,125 − 150 + 5 = 1,730 kcal and a TDEE of about 2,984 kcal — and running 50 km a week adds roughly 3,500 kcal a week, or 500 kcal a day, on top of that.
Your plan, step by step
- Eat a carbohydrate-rich meal 2–3 hours before a long run, and a small snack 30–60 minutes before if needed.
- For runs over 90 minutes, take 30–60 g of carbohydrate per hour from the first hour, plus water.
- After the run, eat carbohydrate (1–1.2 g/kg) and protein (20–40 g) within a couple of hours.
- Eat 5–7 g/kg of carbohydrate a day for moderate mileage (7–10 g/kg for high mileage) and 1.2–1.6 g/kg of protein.
- Practise the exact race-day foods and gels on long runs — never try anything new on race day.
How to use this guide
Use this guide as a template and your own experience as the guide. Some runners run well on an empty stomach in the morning; others need a full breakfast. Some tolerate gels easily; others prefer chews or real food. The principles — carbohydrate before, carbohydrate during long runs, carbohydrate plus protein after — are fixed, but the foods are personal, and the only way to find yours is to practise them in training.
Keep it simple on race day. The meal you have eaten a dozen times before the long run is the meal to eat before the race. The gel you have used on every long run is the gel to use in the race. Race day is the worst possible time for a nutrition experiment, and the best possible time for a routine you trust.
What this guide does NOT tell you
The carbohydrate and protein ranges are population averages from sports-nutrition research: individual needs vary with mileage, body composition, goals and medical conditions, and the figures assume healthy adults without conditions that affect diet. Diabetes, gut conditions, kidney disease and eating disorders all change the answer, and anyone with a medical condition should follow a clinician's or dietitian's plan rather than a general guide.
This guide is general information, not medical advice. It does not diagnose or treat anything, and it cannot tell you what to eat for your specific health situation. The "30-minute window" is less rigid than once believed — the total daily intake matters more than the exact timing — and no supplement is required to fuel running well: ordinary food, eaten at the right times, does the job.
Frequently asked questions
What should I eat before a long run?
A carbohydrate-rich meal 2–3 hours before — porridge with banana, toast with jam, rice with chicken — low in fat and fibre, and something you have eaten before. A small snack (a banana, a slice of toast) 30–60 minutes before is fine if you need it. Avoid high-fat, high-fibre or spicy foods, which slow digestion and cause stomach problems, and never try a new food on race day.
Do I need gels for a half marathon?
Yes, for most runners: a half marathon takes 1.5–2.5 hours, which is long enough to deplete glycogen, and 30–60 g of carbohydrate per hour from the first hour helps maintain pace in the second half. Practise the gels on long runs first — one gel every 30–45 minutes, with water — and use the same products on race day. For a 5K or 10K, gels are unnecessary; the body's stores cover the distance.
What should I eat after a run?
Carbohydrate plus protein within a couple of hours: about 1–1.2 g/kg of carbohydrate (a large plate of rice or pasta for a 75 kg runner) and 20–40 g of protein (a chicken breast, three eggs, or a large serving of Greek yoghurt). Chocolate milk is a good recovery drink because it contains carbohydrate and protein in a useful ratio. Drink to thirst, and eat normally for the rest of the day — the recovery meal is one meal, not the whole diet.
How much carbohydrate does a runner need per day?
About 5–7 g/kg a day for moderate mileage (30–50 km a week), and 7–10 g/kg for high mileage (80+ km a week). At 75 kg, that is 375–525 g a day for the moderate runner — a lot of food, and the reason runners eat so much pasta, rice and bread. Low-carbohydrate diets and high-mileage running are a poor combination: glycogen stores never fill, runs feel flat, and recovery suffers.
Should runners take protein shakes?
They can help, but they are not required: protein shakes are convenient food, not a special recovery product, and a meal with 20–40 g of protein does the same job. Runners need 1.2–1.6 g/kg of protein a day, which most people reach from ordinary food — meat, fish, eggs, dairy, beans. A shake is useful after a run when a meal is not practical, or for runners who struggle to eat enough protein from food alone.
Estimates only, not medical advice. Minimum safe intakes: 1,200 kcal/day women, 1,500 kcal/day men — consult a healthcare professional before a very-low-calorie diet.