Cycling Nutrition and Fueling: Grams per Hour, Timing, and What Actually Digests
Fueling is arithmetic before it is taste. The body stores roughly 400–600 g of glycogen — enough for 90–120 minutes of moderate riding. Beyond that, the difference between a good ride and a bad one is how many grams of carbohydrate you can absorb per hour without stomach trouble.
Carbohydrate per hour
| Ride duration | Carbs per hour | Notes |
|---|---|---|
| Under 60 min | 0–30 g | Water is enough |
| 1–2 h | 30–60 g | One bottle with mix, or one bar |
| 2–3 h | 60–75 g | Mix food forms |
| 3–5 h | 75–90 g | Requires trained gut |
| Over 5 h | 90 g+ | Multiple transportable carbs |
Above 60 g per hour, the limiting factor is absorption, not appetite. Glucose and fructose use different transporters, so a mix of both (roughly 2:1) can push absorption to 90 g per hour — but only if you have practised it.
The practical starting point for a recreational rider is 60 g per hour on rides over two hours. Increase by 15 g per hour across several weeks, not within one ride.
Timing
| When | What | Amount |
|---|---|---|
| 3–4 h before | Normal meal, carbohydrate-led | 1–2 g/kg |
| 60–90 min before | Small snack | 30–60 g |
| Every 20–30 min during | Small portion | 15–25 g |
| Last 30 min | Easy to digest only | 20–30 g |
| Within 60 min after | Carbs plus protein | 1 g/kg carbs |
Eating early and often beats eating a lot at once. A rider who takes 20 g every 25 minutes absorbs more than one who eats 80 g at the 90-minute mark, and avoids the stomach discomfort that comes with a large bolus on the bike.
Sodium
| Conditions | Sodium per hour |
|---|---|
| Cool, easy | 300–500 mg |
| Warm, moderate | 500–800 mg |
| Hot, long, heavy sweater | 800–1,200 mg |
Sodium needs vary more between individuals than carbohydrate needs do. Salt streaks on clothing, headaches after long rides, and cramping late in a ride are practical signals that intake is too low. A 500 ml bottle with an electrolyte tab typically provides 300–500 mg.
Digestibility
| Food | Digests in | Best for |
|---|---|---|
| Gels | 10–15 min | High intensity, late in a ride |
| Chews | 15–20 min | Steady effort |
| Bananas | 20–30 min | Low intensity, real food |
| Bars | 30–45 min | Early in a ride |
| Sandwiches | 45–60 min | Touring, low intensity |
| Nuts | 60 min+ | Not during hard efforts |
The rule: the harder the effort, the simpler the food. Blood is diverted to muscles during hard riding, leaving digestion with less capacity. Eating a nut bar during a threshold interval is how riders end up nauseous at the top of a climb.
Food forms and cost per hour
| Form | Carbs per unit | Cost per hour at 60 g |
|---|---|---|
| Energy gel | 20–25 g | $3–6 |
| Energy bar | 30–45 g | $2–4 |
| Drink mix | 30–60 g per bottle | $1.50–3 |
| Bananas | 25 g each | $0.80–1.50 |
| Dried fruit | 20 g per handful | $0.50–1 |
| Flapjack, homemade | 40 g per piece | $0.40–0.80 |
| Sandwiches | 40–60 g | $0.60–1.20 |
Real food costs a third of commercial sports nutrition and works for anything below 75% effort. Gels earn their price in the last hour of a hard ride or a race, not on a two-hour commute.
What to do on a 100 km ride
Eat a normal carbohydrate meal three hours before. Carry two bottles: one with mix (60 g), one with water. Take a bar in the first hour, a gel or chews at 90 minutes, and real food at the halfway stop. Aim for 60 g per hour total.
Drink to thirst plus a little, with 500–800 mg sodium per hour in warm weather. Eat something within the first hour after finishing — the recovery window is real but it is a window of convenience, not a deadline.
Common mistakes
| Mistake | Result |
|---|---|
| Starting to eat after 2 hours | Bonking at the 2.5-hour mark |
| Drinking only water on a 4-hour ride | Sodium dilution, headaches |
| Trying 90 g per hour for the first time in a race | Stomach shutdown |
| Eating nuts or fibre during hard efforts | Nausea, no absorption |
| Skipping breakfast for an early start | Low glycogen from kilometre zero |
Hydration is part of the plan
Fluid needs scale with heat and effort: roughly 500–750 ml per hour in moderate conditions, up to 1 l per hour in heat. Weighing yourself before and after a ride gives a better estimate than any formula — a 1 kg loss is roughly 1 l of deficit.
For more on fluid and electrolytes, see hydration and electrolytes.
Training the gut
The stomach is trainable, but slowly. If you want to ride at 90 g of carbohydrate per hour, spend four to six weeks building up from 60, practising on rides where the pace is easy enough to tolerate a full stomach.
Start with one session a week at the higher intake, keep the intensity low, and stop increasing if you feel bloated. The adaptation is real — increased gastric emptying and carbohydrate transporter capacity — but it does not happen in a single ride.
When nothing works
Some riders cannot tolerate gels; some cannot tolerate solid food above 70% effort. The practical alternatives are drink mix (absorbed without chewing), chews (small, easy to portion), and real food cut small — banana pieces, flapjack squares, boiled potatoes with salt.
If nausea appears on every long ride, the cause is usually intake rate or intensity, not the product. Reduce grams per hour by 20%, eat earlier, and keep the effort below threshold for the first three hours.
Caffeine and alcohol
Caffeine at 100–200 mg before a ride improves perceived effort for most riders; above 300 mg the stomach and sleep costs outweigh the benefit. Cycling-specific caffeine intake should stop six hours before sleep, or the recovery from the ride is worse than the ride itself.
Alcohol after a ride impairs rehydration and sleep quality. One drink with a meal after a long ride is a choice, not a recovery strategy.
The night before and the morning of
A large carbohydrate meal the night before a long ride does not “load” anything unless it follows two days of similar eating; one big dinner mostly affects sleep. The morning meal matters more: 1–2 g of carbohydrate per kilogram of body weight, three hours before the start, is the practical target.
If the start is early, two smaller meals work better than one large one — something at 5 a.m. and something at 7 a.m. beats forcing 600 calories at 5:30.
Fluid, salt, and the heat variable
On a hot day, carbohydrate intake and fluid intake compete for stomach space. The practical compromise is to concentrate the carbohydrate in one bottle and keep the other as water, so you can drink to thirst without overloading the gut with sugar.
Weigh yourself before and after a long ride in heat. A loss of 2% of body weight is the point where power output and judgement start to fall; 1 kg of loss is roughly 1 litre of fluid.
Where to go next
- Energy gels — what to look for and what to skip
- Post-ride recovery nutrition — the first hour after
- Nutrition before the ride — the pre-ride meal