Your training is only as good as what you put into it. That sounds like a cliche, but practice confirms it time and again: runners who eat smart perform better, recover faster and sustain fewer injuries than runners who barely think about it.
Yet nutrition for runners is not rocket science. You do not need to be a dietitian, count calories or restructure your life around your eating pattern. What you do need: a basic understanding of what your body needs and when, and a few habits that support that.
This hub page gives you the big picture. For each sub-topic you will find a detailed sub-page.
Why nutrition really matters as a runner
Running is a demanding sport for your body. You burn roughly 1 kcal per kilogram of body weight per kilometer. A 75 kg runner who runs 10 km four times a week burns about 3,000 extra kcal every week by running alone. That's a significant amount of energy that has to come from somewhere.
Those who eat too little will notice this during training: their legs feel heavy, concentration drops, and recovery takes longer than normal. Those who eat wrong do not give their body the building materials it needs to become stronger. And anyone who eats at the wrong time unnecessarily sets themselves up for a bad session.
Good running nutrition revolves around three questions: what do you eat before a training session, what do you take with you during a long run, and how do you recover as efficiently as possible afterwards?
The building blocks: what every runner needs to know
Carbohydrates are your fuel
Carbohydrates are the primary source of energy when running, especially at moderate to high intensity. Your body stores them as glycogen in muscles and liver. That supply is limited: for an average runner it runs out after 75 à 90 minutes of intensive walking is largely exhausted. That's the point where "the man with the hammer" strikes.
With gentle zone 2 training, you use more fat as fuel and save glycogen. During more intensive sessions, such as interval training or a tempo run, you are more dependent on carbohydrates. That difference partly determines how you organize your nutrition around training.
Building and repairing proteins
After running, proteins are the most critical nutrient. They repair micro-damage in your muscle tissue, support adaptation to training loads, and help prevent injuries. The guideline for active runners: 1.4 à 1.7 grams of protein per kilogram of body weight per day. For someone weighing 70 kg that is 98 à 119 grams per day, spread over several eating moments.
Fats are not an enemy
Fats are essential for hormone production, fat-soluble vitamins and the maintenance of cell membranes. In endurance sports they also play a role as fuel at low intensity. Don't eliminate them from your diet.
Micronutrients deserve attention
Iron, magnesium, vitamin D and calcium are the nutrients that runners are most often deficient in. Iron deficiency causes fatigue and declining performance. Magnesium deficiency increases the risk of cramps. Vitamin D plays a role in bone health and immune function. A varied diet covers most deficiencies, but athletes who train a lot sometimes have additional needs.
The big picture: timing is everything
| Moment | Target | Key message |
|---|---|---|
| Before training | Replenish glycogen, give the stomach a rest | Carbohydrates 2-3 hours in advance, light and familiar |
| During training | Maintain energy levels | Only necessary after 60-75 minutes of intensive walking |
| After training | Start recovery | Proteins + carbohydrates within 30-60 min |
| Hydration | Monitor fluid balance | Always, not just during training |
The subpages: go deeper into each topic
Nutrition before running
What do you eat the day before a long workout? And what do you take in the morning for an early run? All about timing, portions and which foods leave your stomach at ease.
Nutrition while running
Gels, bars, plain food or nothing: when do you need something during a run, and what works best for your stomach? The practical guide to fueling on the go.
Nutrition after running
The recovery window really exists, but it is broader than many runners think. What you eat in the hours after a workout determines how quickly you'll be ready for the next one.
Hydration for runners
How much do you drink before, during and after a run? What are the signs of dehydration? And when is water no longer sufficient? Everything about fluids and electrolytes.
Supplements for runners
What works, what doesn't, and what you just don't need. An honest review of the most popular supplements for runners.
Alcohol and running
How does alcohol affect your recovery, sleep and performance? And should you really skip a glass of wine the night before a workout?
Frequently asked questions
Should I eat more when I start running?
Can a low-carb diet be combined with running?
In summary
Nutrition for runners isn't a diet: it's a toolbox. Eat enough carbs to fuel your workouts, enough protein to recover, and drink enough to avoid dehydration. The details (timing, quantities, specific products) can be found in the subpages: Nutrition before running, Nutrition while running and Nutrition after walking.
→ Do you also want to know how much you burn per training? Use the calorie calculator.
→ Looking to combine losing weight and running? Read running and losing weight: what really works?
Bart Vandenbussche is passionate about sport and never shies away from a sporting challenge. He has run several marathons (including sub-3h), is an Iron+Ultra Viking, and currently has the Hyrox bug.
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