Why Real Food Works During Endurance Events (And Why It Sometimes Doesn't)
Ask ten endurance athletes what they eat mid-event and you will get ten different answers. Some swear by rice cakes wrapped in foil, some by a squashed banana in the back pocket, some by jam sandwiches cut into quarters. Others will not touch anything that did not come out of a sachet. The truth about real food endurance events fuelling sits somewhere in the middle, and it depends far more on intensity, duration and your own gut than on any ideology about what is "natural".
I have raced on both. I have had a flapjack save a six-hour ride in the Cairngorms, and I have had a cheese roll sit like a brick in my stomach for the final 30km of a hilly sportive. This guide explains what happens physiologically when you eat real food during exercise, where it works, where it lets you down, and how to build a plan around it.
What Your Body Actually Needs From Mid-Event Fuel
Strip the marketing away and mid-event fuelling is about one thing: delivering carbohydrate to working muscle fast enough to spare your limited glycogen stores. A trained athlete carries roughly 400–500g of glycogen in muscle and liver combined. At a solid endurance effort you can burn through 60–90g of carbohydrate an hour, which means the tank runs low somewhere between two and three hours if you take nothing on. That is the bonk, and it does not care whether you planned to eat a banana or a gel.
Current sports nutrition guidance is fairly settled on the numbers. For efforts of one to two and a half hours, aim for 30–60g of carbohydrate per hour. Beyond two and a half hours, 60–90g per hour is the target, and well-trained guts can go higher using a mix of glucose and fructose, because the two sugars use different transporters (SGLT1 and GLUT5) in the small intestine and can be absorbed in parallel.
Real food can absolutely hit those targets. The catch is that real food brings passengers along with the carbohydrate: fibre, fat and protein. All three slow gastric emptying, which is exactly what you want at breakfast and exactly what you do not want at threshold on a climb.
Where Real Food Works: Long, Steady and Cold
The strongest case for real food in endurance events is on long days at moderate intensity. Think all-day audaxes, ultra-distance trail runs, bikepacking and the first two thirds of an Ironman bike leg. Here the pace is low enough that blood flow to the gut is not badly compromised, so your stomach can actually process a bit of fat and fibre.
There are three practical advantages. First, flavour fatigue is real. After four hours of sweet sugar, a salty boiled potato is a psychological reset, and athletes who enjoy their food eat more of it and hit their carbohydrate targets more reliably. Second, real food often carries sodium, which matters on hot days when you can lose 500–1,500mg per litre of sweat. Third, a little fat and protein in a very long event blunts the hunger that sugar alone does not fix after hour six.
Foods that consistently work well for endurance athletes:
- Rice cakes (homemade, pro-team style) — cooked sushi rice with a little sugar and salt, pressed and wrapped. Roughly 25–30g of carbohydrate each, low fat, easy to chew.
- Bananas — around 25g of carbohydrate, some potassium, soft texture. Ripe ones digest faster than green ones.
- White bread with jam or honey — low fibre, high sugar, about 30g of carbohydrate per small sandwich. Skip the butter mid-ride.
- Boiled salted new potatoes — about 15–20g of carbohydrate per handful with useful sodium. Excellent in the last third of an ultra.
The pattern is obvious once you see it: the real foods that work are low fibre, low fat and mostly simple starch or sugar. They are, in effect, gels and chews that happen to grow on trees or come from a rice cooker.
Where Real Food Fails: Intensity, Heat and the Final Hour
Now the other side. Once intensity rises above roughly 75–80% of your maximum heart rate, blood is diverted from the gut to working muscle and skin. Gastric emptying slows, absorption drops and anything sitting in the stomach starts to feel like a mistake. This is why the cheese roll that was lovely at the café stop becomes a problem on the climb after it.
Fat is the main culprit. A typical flapjack carries 8–12g of fat per bar, and fat can slow gastric emptying by an hour or more. Fibre does something similar and adds fermentation, which is where bloating and urgent toilet stops come from. Studies on GI distress in endurance racing repeatedly find that fat, fibre and protein intake during hard efforts predict stomach trouble far better than total carbohydrate does. That is the core reason real food endurance events strategies fail: not the food itself, but eating it at the wrong intensity.
Real food also struggles on three practical fronts:
- Handling. Unwrapping foil and chewing a rice cake at 40kph in a bunch, or on technical singletrack, is not trivial. Dropped food is wasted food.
- Heat. Bananas turn to mush, chocolate melts, bread goes stale and dry. In a Scottish downpour a sandwich becomes paste in the pocket.
- Precision. When you are trying to hit 80g an hour in a marathon or a 70.3, you need to know exactly what each item delivers. "About a handful" is not a fuelling plan.
The last hour of any race, when the effort ramps and the gut is at its most fragile, is where almost everyone should be on fast, simple carbohydrate: something that clears the stomach in minutes rather than an hour.
Building a Plan That Uses Both
The smartest athletes I know do not pick a side. They match the fuel to the phase of the event. A sensible framework for real food endurance events fuelling looks like this:
- Hours 0–2 (or any hard phase): simple carbohydrate only. Chews, pastilles, gel or drink mix. Aim for 60g an hour and keep the stomach light.
- Middle hours at steady pace: introduce real food if the event is long enough to warrant it. One rice cake or half a jam sandwich per hour alongside simple sugars keeps the flavour fresh and the total carbohydrate up.
- Final hour or any finishing effort: back to simple sugars. Stop eating solids 45–60 minutes before the end and rely on quick-clearing carbohydrate.
Whatever you choose, train it. Gut tolerance is trainable, and the athletes who absorb 90g an hour without complaint are the ones who practised on every long session for two or three months. Test each real food at race intensity, not just café pace, and note what worked.
What We Use at FTP Endurance Fuel
Our own approach came out of this exact problem. We wanted something that felt more like food than a synthetic gel, but behaved like a gel in the gut: fast to clear, easy to dose, no fat, no fibre, and pleasant enough to keep eating in hour five. That is what our energy pastilles are. Each one is a fixed dose of glucose and fructose in a 1:1 ratio, so you can count them out to hit 60 or 90g an hour instead of guessing what a banana delivers. They do not melt in a jersey pocket, they do not turn to mush in the rain, and you can eat one with one hand on the bars.
On long steady days we mix them with rice cakes and salted potatoes. On race days and in the final hour we use them alone. Our Tart Cherry Pastilles add Montmorency tart cherry, whose anthocyanins have been shown in several trials to reduce markers of muscle damage and oxidative stress after hard efforts, a useful bonus when stacking back-to-back days. The Mixed Fruit Pastilles are the flavour-fatigue answer for anyone who finds a single taste wears thin. Both come in 1kg bulk packs that work out far cheaper per hour than individually wrapped gels, and the resealable pouch lets you portion exactly what an event needs.
Real food has a place in endurance sport, and anyone who tells you otherwise has never spent eight hours on a bike. But it has a specific place: long, steady, cool and well practised. When the pace goes up, the heat comes on or the finish is in sight, simple carbohydrate wins, and it is not close. Build your plan around the phases of your event, test it in training, and carry fuel you can dose. If you want to try pastilles alongside your usual rice cakes, the Taster Pack is the cheapest way to find out whether they suit your stomach before your next big day out.
