What to Eat Before, During, and After a Run: A No-Nonsense Fuelling Guide

The sports nutrition industry is worth billions of dollars. It has a vested interest in making you believe that running nutrition is complicated, that you need specialised products, and that getting it wrong will cost you performance. Most of that is noise. The fundamentals of fuelling your running are simple, well-established by science, and achievable with food you already have in your kitchen.

That said, the fundamentals matter enormously — especially as your runs get longer and your goals get more ambitious. Here's what science actually says about eating before, during, and after your runs.

Before the run: timing and composition

The goal of pre-run nutrition is straightforward: arrive at the start of your run with enough fuel to sustain the effort without an uncomfortable stomach. The specifics depend on when you're eating relative to when you're running.

2-3 hours before: A normal meal works fine. Something with carbohydrates as the base, moderate protein, and relatively low fat and fibre (both slow digestion and can cause GI distress during running). Rice with dal, toast with banana, oatmeal with honey, or a couple of idlis — familiar, well-tolerated foods that your body knows how to process.

60-90 minutes before: Keep it smaller and simpler. A banana, a few dates, a slice of toast with jam, or a small bowl of rice. The closer to your run, the simpler the carbohydrate should be. Your stomach needs time to move food through, and running with a full stomach is a reliable way to have a miserable time.

30 minutes or less: If you must eat this close to running, stick to easily digestible simple sugars — a few sips of a sports drink, a gel, or a small piece of fruit. Many runners run first thing in the morning on an empty stomach, and for runs under 60-75 minutes, this is perfectly fine. Your body has enough stored glycogen to handle an easy hour without additional fuel.

The best pre-run meal is the one you've eaten dozens of times before. Race day is never the time to experiment with your stomach.

During the run: when fuelling starts to matter

For runs under 60 minutes at easy to moderate effort, you don't need to eat anything. Water is sufficient, and even that may not be necessary if conditions are cool and the effort is gentle. Your body's glycogen stores — roughly 1,500-2,000 calories worth when fully topped up — are more than enough for an hour of running.

For runs between 60-90 minutes, hydration becomes more important but nutrition is still optional for most runners. If you're running easy, your body is burning a mix of fat and glycogen, and the fat supply is essentially unlimited.

Beyond 90 minutes is where during-run nutrition becomes genuinely important. At this point, your glycogen stores are depleting meaningfully, and supplementing with carbohydrates helps maintain your blood sugar, delays fatigue, and sustains your pace.

The form of the carbohydrate matters less than the timing and quantity. Gels work because they're convenient, but dates, bananas, boiled potatoes with salt, rice balls, and even flat cola are all used by endurance athletes around the world. The best mid-run fuel is whatever sits well in your stomach and provides readily available glucose.

Hydration: simpler than you've been told

The hydration industry has done a remarkable job of making us terrified of dehydration while selling us expensive solutions. Here's the reality: for most runs under an hour in moderate temperatures, drinking when you're thirsty is a perfectly adequate hydration strategy. Your thirst mechanism evolved over millions of years to keep you alive. It works.

For longer runs, particularly in heat, a more structured approach helps. Aim for 400-800ml per hour depending on conditions, sweat rate, and body size. If you're running for more than two hours, adding electrolytes — particularly sodium — helps replace what you lose through sweat. A pinch of salt in your water bottle, or a simple electrolyte tablet, does the job. You don't need expensive branded solutions.

Over-hydration is actually a more dangerous condition than mild dehydration. Hyponatremia — diluting your blood sodium by drinking too much water — is a real risk in longer events, especially for slower runners who have more time to drink at aid stations. Drink to thirst, not to a predetermined schedule.

After the run: the recovery window

Post-run nutrition serves two purposes: replenishing glycogen stores and providing the building blocks for muscle repair. The so-called "recovery window" — the idea that you must eat within 30 minutes of finishing or lose all benefit — has been significantly overstated in popular fitness media. But the principle behind it isn't entirely wrong.

Your muscles are indeed most receptive to glycogen replenishment in the first hour or two after exercise. If you have another hard session within 24 hours, eating carbohydrates relatively soon after your run is beneficial. If your next hard session is two days away, the urgency is much lower — your body will replenish glycogen stores from your normal meals over the next 24 hours regardless.

A practical post-run approach: eat a normal meal within 1-2 hours of finishing. Include carbohydrates to replenish glycogen, protein for muscle repair (20-30g is sufficient), and don't overthink it. Curd rice, a dosa with sambar, eggs on toast, or whatever you would normally eat is fine. The specifics matter far less than the consistency.

Race day nutrition: the dress rehearsal matters

Everything changes on race day. The intensity is higher, the duration is longer (for most), the nerves are real, and your GI system is under more stress. This is why the single most important rule of race day nutrition is: never try anything new.

Every gel, every drink, every pre-race meal should be something you've tested repeatedly in training. Your long runs are your nutrition rehearsals. Use them to figure out what your stomach tolerates at race effort, when to take in calories, and how much fluid you need.

For a marathon, practice your fuelling strategy on at least three or four long runs before race day. Start taking in carbs earlier than you think you need to — by the time you feel depleted, it's too late. Aim to take your first gel or snack at around the 45-minute mark and continue every 30-45 minutes thereafter.

Carb loading: demystified

Carbohydrate loading before a race is a real, scientifically validated strategy — but it doesn't mean eating mountains of pasta the night before. The modern approach to carb loading involves increasing your carbohydrate intake to roughly 8-10 grams per kilogram of body weight for 36-48 hours before the race, while tapering your training volume.

For a 70kg runner, that's 560-700 grams of carbohydrates per day in the two days before the race. That's a significant amount — you'll need to actively think about increasing carbs with every meal and snack. Rice, bread, pasta, fruits, juice, and even sweets all count. Reduce fat and fibre to make room and to minimise the risk of GI issues on race morning.

This applies primarily to events lasting longer than 90 minutes. For a 5K or even a 10K, your normal diet provides more than enough glycogen. Don't carb-load for a parkrun — your body already has the fuel it needs.