Most recreational runners underestimate how directly their food choices affect performance. Not in a vague, general-health kind of way — but in a very concrete sense: you bonk at kilometre 30 because glycogen stores ran out, you struggle to recover between sessions because protein intake is too low, you feel heavy on race morning because you ate the wrong thing the night before. Nutrition is not a nice-to-have layer on top of your training. It is part of your training, and it works the same way — when it’s dialled in, everything else gets easier.
Why Runners Need to Think About Nutrition Differently
Running is an extremely glycogen-dependent sport. Unlike cycling or swimming, where you can adjust intensity more freely, running at any meaningful pace draws heavily on your carbohydrate stores. Your muscles and liver together hold roughly 400–500 grams of glycogen at full capacity — enough to fuel approximately 90 minutes of sustained running. Once those stores are depleted, performance drops sharply. The practical implication is that runners need to think about carbohydrate not just as a food group but as a managed resource: how full are my stores going into this session, how fast am I burning them, and how do I replenish them afterwards?
Protein matters too, but for different reasons. It does not fuel your run directly. It repairs the microscopic muscle damage that running causes and supports the adaptation process that makes you fitter over time. Inadequate protein intake is one of the main reasons runners stagnate despite consistent training — the body cannot rebuild effectively between sessions. Fat rounds out the picture as a structural and hormonal substrate and as a fuel source at lower exercise intensities, but it requires no special attention beyond eating a broadly varied diet.
The ratio most sports nutrition researchers settle on for endurance-focused runners is roughly 55–65% of calories from carbohydrates, 15–20% from protein, and the remainder from fat. That said, individual needs vary based on training volume, body weight, and goals. The numbers below are useful reference points, not rigid prescriptions.
Daily Nutrition: Building the Base
Before race-day strategies and intra-run fuelling make any sense, your everyday diet needs to provide the foundation. Think of it as the baseline from which everything else works — if daily nutrition is poor, the tactical stuff around training sessions yields far less return.
Carbohydrate intake for runners scales with training load. A useful framework: recreational runners logging 40–60 km per week need roughly 5–7 grams of carbohydrate per kilogram of bodyweight per day. At higher volumes, that rises toward 8–10 grams. The best sources are those that come with fibre, vitamins, and minerals attached — oats, rice, sweet potato, whole grain bread, pasta, legumes, and fruit. Simple refined carbohydrates are not inherently harmful but provide little beyond energy, so they should not dominate.
Protein targets for runners sit between 1.4 and 1.8 grams per kilogram of bodyweight per day — higher than general population recommendations, because training creates consistent muscle damage that needs repairing. Spreading intake across meals is more effective than eating it all at once; the body can only use roughly 20–40 grams per meal for muscle protein synthesis. Lean meats, fish, eggs, dairy, and plant-based sources like legumes and tofu all work. The specific source matters less than hitting the target consistently.
Hydration deserves a note here: most runners drink enough around training but go into sessions mildly dehydrated simply because their baseline daily fluid intake is insufficient. Pale yellow urine is the most practical gauge. Electrolytes — sodium, potassium, magnesium — matter increasingly as session length and sweat rate increase. Water alone is adequate for runs under an hour; beyond that, electrolyte replacement becomes relevant.
What to Eat Before a Run
Pre-run nutrition depends almost entirely on session length and intensity. The general principle is that you want to arrive at the start of your run with topped-up glycogen stores and without anything sitting heavily in your stomach.
For runs under 45–60 minutes, a normal meal eaten two to three hours beforehand is sufficient. No special pre-run snack is necessary. For runs of 60–90 minutes or longer, particularly at moderate to high intensity, a carbohydrate-rich snack 30–60 minutes before can meaningfully support performance. Easily digestible options — a banana, a slice of toast with jam, a handful of dried dates — work better than protein-heavy or high-fat choices, which slow gastric emptying and can cause discomfort on the move. Avoid high-fibre foods in the two hours before a hard session or long run; the digestive stimulation running causes makes high-fibre intake a reliable way to derail a session.
For a detailed breakdown of timing windows, portion sizes, and real-food alternatives to commercial pre-run products, the guide to what to eat before a long run covers this in full.
Fuelling During a Run
Under 60 minutes of easy running: you do not need to eat anything. Glycogen stores are sufficient, and consuming calories mid-run at this duration provides no meaningful performance benefit. Water is all you need.
Beyond 60–75 minutes, particularly at race or threshold effort, carbohydrate intake during the run maintains blood glucose and delays glycogen depletion. The research consensus sits around 30–60 grams of carbohydrates per hour for most runners, with some elite athletes training up to 90 grams per hour using dual-source carbohydrate formulations (glucose plus fructose). For recreational runners, 30–45 grams per hour is a practical target for long training runs.
Energy gels are the most popular delivery vehicle because they are precise, portable, and fast-absorbing. Commercial options like the Maurten Gel 100, SiS Beta Fuel, and GU Energy Gel are designed around these targets and have been tested by millions of runners at all levels. They differ in carbohydrate composition, texture, and how well individual runners tolerate them — which is why testing in training before race day is non-negotiable. Gut tolerance is highly individual, and what works for one runner causes GI distress in another.
If you race a half marathon and want a complete fuelling framework — how many gels to carry, when to take them, how to combine them with hydration — the guide to fuelling a half marathon covers the full protocol.
If you prefer to skip commercial products entirely and fuel with real food, that is a completely workable approach. Bananas, dates, rice cakes, boiled baby potatoes with salt — all of these have been used successfully at every race distance. The principles are the same: easy-to-digest carbohydrates, small amounts, taken regularly. The guide to real food for runners is the best starting point if that route appeals to you.
Recovery Nutrition: The Window That Matters
The 30–60 minutes after a hard or long run is the highest-leverage nutritional window in your training week. Muscle glycogen resynthesis is fastest in this window because muscle cells are maximally sensitive to insulin and actively pulling glucose from the bloodstream. Delaying post-run nutrition by several hours meaningfully slows recovery and compromises your ability to train well in the following 24–48 hours.
The basic formula is straightforward: carbohydrate to replenish glycogen, protein to initiate muscle repair, and fluids plus electrolytes to replace what was lost in sweat. A ratio of roughly 3:1 or 4:1 carbohydrate to protein is commonly cited in the literature for the immediate recovery window. In practice, a meal containing rice or pasta with a protein source, or a recovery shake combining fast-digesting protein like whey with carbohydrates, both achieve this. The Optimum Nutrition Gold Standard Whey is one of the most widely used options for the protein component; tart cherry juice has a reasonable evidence base for reducing post-run inflammation and muscle soreness. If you want a full breakdown of protein types, timing, dosing, and which option suits your situation — including soy-free plant-based alternatives — the guide to protein for runners covers this in detail.
For a full breakdown of recovery nutrition — what to eat, when, and what the evidence actually says about recovery supplements — see the guide to what to eat after a long run.
Race Week and Carbohydrate Loading
In the final days before a goal race, the objective is to maximise glycogen stores without gaining unnecessary water weight or disrupting routines that have worked well in training. Carbohydrate loading — deliberately increasing carbohydrate intake in the 24–48 hours before a race — is well-established for events lasting 90 minutes or more. The target is approximately 8–10 grams of carbohydrate per kilogram of bodyweight per day during the loading phase.
The practical error most runners make is eating unfamiliar foods, trying new products, or dramatically overeating in the days before a race. The purpose of the loading phase is to top up stores, not to consume twice your normal calories. Stick to foods that have worked throughout your training. Reduce fibre intake modestly in the final 24 hours to reduce gut contents — this is standard race-week protocol and has nothing to do with long-term diet quality.
Race morning: eat a familiar carbohydrate-focused breakfast two to three hours before the start. Porridge with banana, toast with jam, or a bagel are all reliable options. Nothing new on race day — that applies to food as firmly as it applies to footwear. If you’re still in the process of choosing the right pair, the guide to the best running shoes for beginners covers what to look for and which models consistently deliver.
Energy Gels and Commercial Products: When They Help and When They Don’t
Commercial sports nutrition products are tools, not requirements. They excel in specific contexts: during races and long training runs where convenience, precision dosing, and speed of absorption matter. They are not necessary for general training sessions, easy runs, or daily nutrition. The marketing suggests otherwise, but the evidence does not.
If you want a detailed comparison of the leading energy gels — how they differ in formulation, who they suit, and what you actually need to know before buying — the guide to the best energy gels for runners gives you the full picture.
If you want to make your own sports nutrition — isotonic drinks, energy balls, rice cakes, recovery smoothies — the guide to homemade sports nutrition recipes covers the most practical options with guidance on when a commercial product genuinely outperforms what you can make at home.
The Only Nutrition Principle That Consistently Works
Almost every runner who makes real progress in their nutrition does so not by optimising supplements or chasing the latest product, but by consistently eating enough of the right things at the right times. Underfuelling — running on insufficient carbohydrate, skipping post-run recovery nutrition, going into hard sessions on empty — is responsible for more training stagnation and injury risk than any other nutritional factor. The research on Relative Energy Deficiency in Sport (RED-S) is clear on this point: chronically low energy availability impairs performance, hormonal function, bone health, and immune response.
The framework here is straightforward to remember: fuel your effort, recover from your effort, and eat a varied enough diet the rest of the time that micronutrient needs are met without chasing supplements. If something is not working — persistent fatigue, poor sleep, stagnating performance — nutrition is often where the answer lies, and the framework above is the diagnostic starting point.
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