The real question isn’t whether to eat carbs – it’s which ones, how much, and when. This guide walks you through the best carbohydrate sources for triathletes, from everyday meals to race gels, with actual gram numbers and timing. We’ll keep it simple, grounded in sports nutrition research, and written for real people who have to train before work, not live in a lab.
Why Carbs Matter for Triathletes
Carbs = glycogen (and glycogen is limited)
Carbohydrates are stored in your muscles and liver as glycogen. Those stores are limited – roughly enough for about 90–120 minutes of moderate–hard work if you haven’t topped things up properly. Once glycogen starts to run low, you don’t just “feel a bit hungry”: power fades, pace drops, and your brain becomes much less interested in your heroic race plan.
Daily targets (what “enough” looks like)
Sports nutrition position stands are very consistent on this: endurance athletes perform better on a carbohydrate-rich diet, with daily intakes generally somewhere between 5–10 g of carbohydrate per kilo of bodyweight, depending on training load. Before long events, increasing that to around 10–12 g/kg/day for a day or two – classic “carb loading” – can push glycogen above normal levels and extend time to fatigue.
Race targets (where most people underdo it)
During exercise, the research is equally clear. For longer events, taking in carbohydrate while you move improves endurance, pacing, and even perceived effort. Rough guidelines are about 30–60 g per hour for shorter endurance events and up to 60–90 g per hour for ultra-endurance or very long races. For triathletes doing half-IRONMAN or full-distance IRONMAN, that upper range isn’t optional – it’s often the difference between running and shuffling.
In other words, triathlon carbohydrate intake isn’t about perfection or spreadsheets. It’s about making sure that when you ask your body for another hard kilometre, there’s actually some fuel left in the tank.
- Daily: ~5–10 g/kg/day depending on training load.
- Pre-race (24–48h): ~7–10 g/kg/day (up to ~10–12 g/kg/day for long events if tolerated).
- During: 30–60 g/h (shorter) or 60–90 g/h (70.3/full).
- Recovery: 0.5–1.0 g/kg carbs + ~0.3 g/kg protein within the first hour
- Practise your grams-per-hour plan in training (your gut is trainable)
Best carbohydrate sources for daily training
Your daily carb intake is the quiet background work. Get it right and training feels like training; get it wrong, and every session feels like you’ve started halfway through the workout.
Oats are an easy anchor. Around 60 g of dry oats – a generous bowl – gives roughly 40 g of carbohydrate before you even add milk, yoghurt, fruit, or honey. They’re ideal for breakfast or a second breakfast after an early swim, and they release energy relatively steadily rather than spiking and crashing.
Rice, both white and brown, is another staple. A typical serving of 150–200 g cooked rice provides somewhere in the 40–60 g carbohydrate range. Brown rice brings more fibre and micronutrients; white rice is easier on the stomach and often preferred when training load is high, or the session is close. Many endurance athletes quietly switch to white rice in heavy training blocks, not because it’s “healthier”, but because it’s easier to tolerate in large amounts.
Pasta fulfils a similar role. A normal plate of cooked pasta – in the 170–200 g region – will usually deliver 55–60 g of carbohydrate before you even think about sauce. Paired with a simple tomato or olive oil-based sauce and a modest portion of lean protein, it’s an easy way to push daily intake up into that 7–10 g/kg/day zone when training gets serious.
Don’t ignore potatoes and sweet potatoes, either. About 200 g of boiled potatoes or sweet potatoes gives roughly 35–40 g of carbohydrate. They’re satisfying, versatile and, interestingly, not just “plate fuel”. A neat study a few years back compared potato purée to commercial gels during prolonged cycling at around 60 g of carbohydrate per hour. When the total carbs were matched, the potatoes were just as effective as gels for maintaining blood glucose and time-trial performance – proof that real-food carbs can work as training fuel as well as on the dinner table, provided you manage the volume and texture.
Day to day, bread and wraps are your convenience carbs. Two slices of bread or one large wrap usually sit in the 30–35 g carb range, making sandwiches, toast, and wraps simple ways to add fuel around sessions. On heavier days or before key workouts, using white bread instead of very high-fibre wholegrain can reduce the risk of gut rebellion without compromising fuel.
Then there’s fruit. A medium banana typically has about 25–27 g of carbohydrate. A small handful of dates can easily add another 20 g. These make ideal snacks between meals, pre-session top-ups, or part of a recovery snack, and they bring potassium and antioxidants along for the ride.
If you want a ready-made carb–protein combo, yoghurt with granola or cereal works well. Two hundred grams of yoghurt with 40 g of granola will often land you around 40–50 g of carbs, plus a useful hit of protein and calcium. That’s perfect for mid-morning after a swim, or afternoon recovery when there’s an evening run still to come.
The overall idea for daily life is simple: build meals around one or two of these carb sources, then add sensible amounts of protein, fat, and colour. You don’t have to count every gram, but knowing roughly what a bowl of rice or a bagel gives you stops everything from becoming guesswork.
Pre-race carbohydrate foods for triathletes
The goal: top off glycogen without gut drama
The 24–48 hours before a race are about topping off glycogen without upsetting your stomach. Sports nutrition guidelines for endurance events usually recommend around 7–10 g of carbohydrate per kilo of bodyweight per day in the lead-up to big races, and a final pre-race meal that contains 1–4 g/kg of carbohydrate, eaten 1–4 hours before the start, low in fat and fibre and very familiar.
Night-before meal ideas
In practice, that often looks like simple rice or pasta dishes the evening before – for example, a large plate of white rice or pasta with a light tomato sauce and a modest portion of chicken, fish or tofu. A 200 g serving of cooked rice will provide around 55–60 g of carbohydrate; add some bread or a second helping, and it’s easy to climb into the 150–200 g range across the meal without feeling stuffed.
Race morning breakfast (1–4 hours before)
On race morning, many triathletes gravitate towards bagels with jam or honey and nut butter. One plain bagel typically gives 45–50 g of carbohydrate, and a tablespoon of jam or honey adds another 15–18 g. Two bagels with a conservative amount of topping can therefore get you close to 100 g of carbs in a format that’s easy to chew, familiar, and relatively low in fibre.
If you prefer cereal, a bowl of low-fibre breakfast cereal with milk does a similar job. Something like 50 g of cereal with 200–250 ml of milk generally puts you in the 45–55 g carbohydrate range. The key here is not to choose the densest, nut-and-bran creation in the supermarket the morning of your A-race. Pre-race is not the moment to show off your fibre intake; keep things plain, simple, and familiar.
Final 60–90 minutes: small top-ups
In the final 60–90 minutes before the start, small top-ups can make a difference without feeling like another full meal. A ripe banana and a 500 ml bottle of sports drink can easily provide another 55–60 g of carbohydrate. That “bridge” between breakfast and the gun start helps avoid long gaps without fuel, particularly if your wave time is delayed.
Carbohydrates during triathlon races
Set your grams-per-hour target first
This is where triathletes often fall short: the plan says 70 g per hour, the reality is “two gels and a hope”.
Research on endurance performance during prolonged exercise consistently shows that consuming carbohydrate during the effort improves time to exhaustion and time-trial performance, as long as intake is high enough and well-tolerated. For events around the two-hour mark, 30–60 g per hour is usually sufficient. For longer events – which most non-sprint triathlons are – targets move up towards 60–90 g per hour.
Bike leg: easiest place to hit your numbers
On the bike leg, you have the best opportunity to hit those numbers. It’s relatively stable, you can carry bottles and food, and you’re not bouncing up and down like you are on the run. A common pattern might be one 500 ml bottle of sports drink at around 6–7% carbohydrate, giving roughly 30–35 g, plus one energy gel providing 20–30 g, and perhaps a few chews or a chunk of banana if needed. Suddenly, you’re in the 60–70 g per hour range without extreme measures.
Sports drinks that combine glucose or maltodextrin with fructose are particularly useful here, as they use different intestinal transporters and allow higher rates of carbohydrate absorption and oxidation than glucose alone. That’s the “multiple transportable carbohydrates” concept in the real world – more on that shortly.
Run leg: little and often wins
On the run, everything becomes a bit more delicate. You’re hotter, your gut is moving around more, and your appetite for solid food probably drops. Gels and sports drink taken little and often tend to work best here. A gel every 20–30 minutes, washed down with water or a sports drink, is more realistic than trying to choke down bars. Aid-station bananas can chip in, but relying on fruit alone for a marathon after a long ride is optimistic at best.
Real food vs gels: use it where it makes sense
Real-food options such as boiled salted potatoes or rice cakes can have a place, particularly on the bike in long-course racing. As mentioned earlier, the potato purée vs gel study showed that potatoes, when eaten in sufficient quantity to match around 60 g of carbs per hour, supported cycling performance as well as gels. The catch is practicality: potatoes take up more stomach space and require more chewing. On the bike, where intensity is lower relative to maximum and posture is more stable, that’s manageable; on the run, it’s usually not.
The central question during the race is always: “How many grams per hour am I hitting?” Once you can answer that with something better than a shrug, everything gets a lot easier to plan and refine.
Best recovery carbohydrate sources
First hour target (carbs+protein)
After a hard race or key session, your body is trying to rebuild glycogen, repair muscle, and restore fluid balance. Recovery nutrition guidelines typically suggest about 0.5–1.0 g of carbohydrate per kilo of bodyweight in the first hour or so after exercise, combined with roughly 0.3 g/kg of protein. If you’ve got another session within 24 hours, that early carb intake becomes even more important.
Here, liquid and semi-solid options often work best because your appetite may not have caught up with the work you’ve just done. A classic example is chocolate milk: 500 ml typically contains around 45–50 g of carbohydrate and 18–20 g of protein, which neatly hits both carb and protein targets for many athletes in a single, easy drink.
Home-made smoothies are another useful tool. A blend of banana, berries, perhaps a spoonful of oats, and yoghurt or milk can fairly easily deliver 50–70 g of carbohydrate, plus some protein and micronutrients. Because you drink it rather than chew it, it tends to go down better after a long brick or race.
Easy recovery options when appetite is low
As soon as you can face a proper meal, going back to something like a rice bowl with lean protein and some vegetables is ideal. A 250 g serving of cooked rice contains around 65–70 g of carbohydrate on its own, and you can always add bread or fruit if you need more.
Follow-up meal within 2–3 hours
Even in the evening, a basic bowl of cereal with milk can play its part. Sixty grams of cereal plus 250 ml of milk will often sit in the 60–70 g carb range and can be a simple way to top off glycogen before bed after a heavy training day.
The pattern is simple: carb + protein as soon as you can after your workout, then another solid, carb-rich meal within a couple of hours.
Triathlon carbohydrate intake: how much do you need?
Daily intake by training load
Zooming out, daily targets depend on your training load.
On rest days or very light training, something in the region of 3–5 g of carbohydrate per kilo of bodyweight per day is usually enough. For moderate endurance training – think 1–2 hours per day most days – sports nutrition guidelines push that up into the 5–7 g/kg/day range. When you hit heavy training blocks, multiple sessions, or race weeks, the recommended range rises to 7–10 g/kg/day.
For a 70 kg triathlete, that means anywhere from around 350 g per day on the low end up to 700 g or more on the very heavy days. That sounds like a lot until you realise that a decent bowl of oats, a couple of bananas, a rice-based lunch, and a pasta-heavy dinner will get you there without anything exotic.
Race intake by distance
During the race, the numbers depend on the distance. In a sprint triathlon lasting about 60–90 minutes, a modest intake of 30–40 g per hour, mostly on the bike, is often enough. For standard/Olympic distance events in the 2–3 hour window, athletes commonly aim for 40–60 g per hour, again heavily biased to the bike.
Once you move into half and full Iron-distance, fuelling becomes serious logistics. On the bike in a 70.3, many athletes will aim for 60–90 g per hour, then maintain something in the 40–70 g/h range on the run, depending on gut tolerance and pace. Full-distance racing often uses similar numbers but sustained for much longer, which is why practising this in training – and using those multiple transportable carbohydrates – matters so much.
Multiple transportable carbohydrates explained
Why mixing sugars helps
This term sounds like it belongs in a physiology exam, but the idea is simple: if you use more than one type of sugar, you can absorb more per hour.
Glucose (and its near relative maltodextrin) uses one intestinal transporter; fructose uses another. When you take in only glucose-based carbs, the gut tends to cap out around 60 g per hour before absorption becomes limiting and gut complaints increase. When you mix glucose and fructose in the right ratios, research shows you can push effective carbohydrate use up towards 90 g per hour with better tolerance.
What to look for in drinks/gels
That’s why so many modern sports drinks and gels are explicitly labelled as glucose–fructose or maltodextrin–fructose blends. They’re designed to make those higher carb intakes physiologically possible, not just theoretically desirable. You can mimic this with food by combining, say, a banana (which naturally contains fructose and glucose) with a maltodextrin-based drink.
Simple food-based workaround
You don’t need to memorise transporter names. Just know that for long races, products offering mixed carb sources are your ally, and that hitting 80–90 g per hour from a mix of drink, gels, and perhaps a little real food is far more realistic than trying to choke down the same amount from pure glucose.
Testing carb sources in training
Train the gut (progressively)
Plenty of triathletes know these numbers but never come close to them on race day, usually because they’re worried about their stomach, or because they’ve never actually practised fuelling at race intensity.
Your gut is trainable, just like your legs and lungs. That means using long bikes and brick sessions to practise the fuelling plan you intend to use in competition. If your race target is 70 g of carbohydrate per hour on the bike, you should be working up to that in training: start with 40–50 g/h, then gradually increase towards your goal as your body adapts.
Test at race intensity, not café pace
Pacing matters too. Fuelling at café-ride intensity is not the same as fuelling at race pace. Some of your testing should be done at realistic effort levels, especially on the bike, where you’ll take in the bulk of your carbs for longer races.
Use indoor sessions to control variables
Indoor riding is perfect for this. On a long ROUVY route, you can hold a steady power, remove the variables of weather and traffic, and see exactly how different fuel combinations feel. One session, you might try drink plus gels; another, you might experiment with drink plus chews and small potatoes or rice cakes. If your stomach complains at 80 g/h, dial back to 60–70 g/h and sit there for a while before pushing again.
The bottom line: you don’t want race day to be the first time your gut has seen your race fuelling plan!
Conclusion and quick reference chart
If all of this feels like a lot, bring it back to something simple:
- Use familiar, carb-rich foods like oats, rice, pasta, potatoes, bread, fruit and yoghurt to meet your daily needs.
- In the 24–48 hours before big races, increase those portions and lean on low-fibre, easily digested options like white rice, pasta, bagels, and simple cereals.
- During the race, have a clear grams-per-hour target and hit it mainly with sports drinks, gels, and chews, with real-food extras on the bike if you tolerate them.
- After hard sessions, combine substantial carbs with protein to refill glycogen and accelerate recovery.
