Last Updated on 1 July 2025 by Chris
Almost every cyclist knows the feeling. Suddenly, your legs stop pushing, your heart rate goes haywire, and every pedal stroke hurts. This is the classic so-called ‘bonk’ – also referred to as hitting the wall or an energy crash. In this post, we’ll break down exactly what, when, and how much to eat and drink in order to maintain power and comfort all the way to the finish line – whether you’re riding 100 km solo or racing 350 km in an ultra event.
Causes of an Energy Crash While Riding
Sudden weakness, heavy legs, dizziness, or mental fog – these are classic signs of a bonk, a rapid drop in available energy during exercise. The main cause of this phenomenon is the depletion of glycogen stores in the muscles and liver – the body’s primary source of fuel at high intensity.
During moderate to intense rides, your body draws most of its energy from carbohydrates, breaking down glycogen into glucose. However, even in well-trained athletes, glycogen reserves are limited – they typically last for just 60-90 minutes of hard riding without refueling. Once these stores are depleted, the body switches to emergency mode, attempting to rely on fat as an energy source – which is a much slower and less efficient process. The result is a sudden drop in power, trouble focusing, and sometimes symptoms that resemble hypoglycemia.
It’s important to note that a bonk can also be caused by multiple factors. In addition to carbohydrate deficiency, it can be triggered by:
- dehydration, which reduces blood plasma volume and impairs oxygen transport,
- electrolyte imbalances (e.g. sodium, magnesium, or potassium deficiency),
- overheating, which redirects blood flow from muscles to the skin,
- insufficient fueling before the ride or starting to eat too late during the ride,
- pacing mistakes – going too hard at the beginning compared to your metabolic capabilities.
Smart fueling and hydration aren’t just about comfort – they are your protection against energy collapse. Strategically planning carbohydrate intake helps maintain metabolic balance, sustain power, and avoid physiological breakdown at a critical moment during the ride.
1. BEFORE THE RIDE – Build Your Base
Proper carbohydrate loading before a ride is essential to maximize glycogen stores. It’s recommended to consume complex carbs several hours before your training, and simple carbs shortly before to quickly raise blood glucose levels.
A successful ride or race doesn’t start when you clip in – it begins hours before you get on the bike. That’s when you lay the foundation of your fueling strategy: maximizing your body’s stores of readily available energy. It’s not about feeling full – it’s about mobilizing metabolic resources.
The energy required for riding comes primarily from:
- muscle glycogen (about 300-500 g),
- liver glycogen (about 100-150 g),
- glucose circulating in the blood.
This adds up to around 2,000 kcal – enough for 60-90 minutes of high-intensity riding. But you need to build this reserve deliberately, which is why planning your pre-ride meal 2-3 hours before getting on the bike is crucial.
Pre-Ride Guidelines (2-3 Hours Before Start):
| Macronutrient | Recommended Amount (per kg body weight) | For a 70 kg Cyclist |
|---|---|---|
| Carbohydrates | 1.0 – 2.0 g/kg | 70 – 140 g |
| Protein | 0.2 – 0.4 g/kg | 14 – 28 g |
| Fat | 0.1 – 0.3 g/kg | 7 – 21 g |
Use the higher end of the range before long rides (3-5h+), and the lower end for shorter rides (1-2h).
How to Convert This Into Food?
Example meal for a person weighing 70 kg:
| Food Item | Amount (g) | Carbs | Protein | Fat |
|---|---|---|---|---|
| Oatmeal (dry oats) | 70 | 42 | 8 | 5 |
| Honey (in the oatmeal) | 20 | 16 | 0 | 0 |
| Banana | 120 | 27 | 1 | 0 |
| Peanut butter (1 tbsp) | 15 | 3 | 4 | 8 |
| Oat drink (200 ml) | 200 ml | 10 | 2 | 1 |
| TOTAL | ~98 g | ~15 g | ~14 g |
This gives us:
- ~1.4 g carbohydrates / kg
- ~0.2 g protein / kg
- ~0.2 g fat / kg
What to Eat? Specific Examples:
1. “Cyclist’s Oatmeal” (for a 70 kg rider):
- 70 g oats (42 g carbs),
- 1 banana (27 g carbs),
- 15 g honey (12 g carbs),
- 15 g peanut butter (4 g protein, 8 g fat),
- 200 ml oat milk (10 g carbs, 2 g protein),
- pinch of salt (helps retain water).
Total: ~100 g carbohydrates, 14-16 g protein, 10-14 g fat.
A well-balanced, light but high-energy meal.
2. Rice with Add-ons (for a 70 kg rider):
- 150 g cooked jasmine rice (39 g carbs, 3 g protein),
- 1/2 banana (14 g carbs),
- 20 g fruit jam (12 g carbs),
- 10 g peanut butter (2 g carbs, 2.5 g protein, 5 g fat),
- 200 ml plain drinking yogurt 2% (9 g carbs, 7 g protein, 3.2 g fat),
- pinch of salt (supports electrolyte balance).
You can mix the jam and banana into the rice, and drink the yogurt separately. This combo is gentle on the stomach and provides stable energy for the first hours on the bike.
Total: ~76 g carbohydrates, ~13 g protein, ~9 g fat.
Easily digestible and gut-friendly pre-ride meal that fuels you well for 1.5-2.5 hours of riding.
3. Simple and Fast – Bread Rolls with Honey + Kefir (for a 70 kg rider)
- 2 wheat rolls (120 g – about 60 g carbs, 9 g protein),
- 1 banana (27 g carbs),
- 20 g honey (12 g carbs),
- 15 g butter (approx. 12 g fat – optional, for longer rides),
- 250 ml plain kefir (8 g carbs, 7 g protein, 5 g fat),
- pinch of salt
Total:
– without butter: ~107 g carbohydrates, ~16 g protein, ~5 g fat,
– with butter: ~107 g carbohydrates, ~16 g protein, ~17 g fat.
This breakfast is extremely quick to prepare and is well tolerated even before high-intensity rides. Butter can be skipped if you’re planning a shorter session or want to limit fat intake before the ride (as it takes longer to digest and may cause a feeling of heaviness).
30-60 Minutes Before the Ride. Quick Top-Up:
If it’s been a few hours since breakfast and your ride is about to start, it’s worth topping up your energy gently:
- 1 banana,
- 1 energy bar (25–30 g carbs),
- 1 bidon of isotonic or carb-rich drink (e.g. 30 g maltodextrin/500 ml).
This is a simple way to raise blood glucose levels without triggering an insulin spike.
What to Avoid Before a Ride?
- heavy-to-digest fats (cheese, fried foods),
- high-fiber foods (raw vegetables, whole grains),
- excessive amounts of protein (can overload the stomach),
- large servings of meat,
- “fit” products like chia seeds, flax seeds, protein shakes – unnecessary before a ride.
Some foods can leave you feeling sluggish or cause stomach discomfort during your ride. Fatty meals – especially fried ones – are best avoided. A common mistake among cyclists is trying new things right before an important event. Stick to meals you’ve tested before. The key is to provide energy in a way that doesn’t stress your digestive system.
2. During the Ride
Once you’re out on the bike, it’s no longer the time to “wait with eating.” This is the key moment when you need to start managing your energy before it runs out. Otherwise, you’re heading straight toward a guaranteed bonk.
Why Is Regular Fueling So Important?
During exercise, your body uses:
- muscle glycogen as the primary fuel,
- glucose from the blood, which needs constant replenishment,
- fat (mainly during low-intensity efforts).
If you don’t supply carbohydrates regularly, blood glucose drops and your muscles go into emergency mode. Instead of holding your pace, you’ll gradually fade.
How Many Carbs Do You Need?
Recommendations depend on the duration and intensity of your ride:
| Ride Duration | Carb Intake (g/h) | Food per Hour of Effort |
|---|---|---|
| up to 60 minutes | 0 g (or 20-30 g at high intensity) | small gel or sugary drink |
| 1–2.5 hours | 30-60 g / h | e.g. 1 bar + 1 gel |
| 2.5–4 hours | 60-90 g / h | isotonic drink + 2 gels + jam sandwich |
| 4+ hours | 80-120 g / h (if gut-trained!) | glucose + fructose mix, gels, bars |
It’s generally accepted that the body can absorb up to 60 g of glucose plus 30 g of fructose per hour. That gives you a total of 90 g of carbs per hour – the upper limit without specific gut training.
Explanation: the combination of 60 g glucose + 30 g fructose = 90 g/h. Using glucose and fructose together in a ~2:1 ratio (or 1:0.8) allows most people to reach the maximum carbohydrate oxidation rate of up to 90 grams per hour. This is considered the “upper limit without gut training,” i.e., without specific intestinal adaptation.
Hydration During Exercise
In cycling, just like in other endurance sports, fluids are just as important as fuel (carbohydrates). While water is the foundation of life and makes up about 60% of an adult’s body mass, in the context of physical effort it becomes part of a complex performance strategy.
Your performance and mental focus rely heavily on how well-hydrated you are. Lack of proper hydration is a recipe for a drop in form, discomfort, and even serious health issues.
Water may be essential to life, but in cycling, hydration is a strategic element that directly affects your performance, concentration, and even the digestion of gels and bars. You can have a perfectly planned fueling strategy – but without fluids, it simply won’t work.
How Much Should You Drink?
The old and wise rule says: drink regularly before you feel thirsty. Thirst is already a sign of dehydration. In cycling hydration strategy, you should take small sips regularly (e.g. every 10-15 minutes) from the very beginning of your ride.
General Recommendations:
- 500-750 ml of fluids per hour
- In hot weather: even up to 1000 ml/h (if tolerated)
If you drink less than 500 ml/h, dehydration begins
As a result, you may experience the following negative effects:
- reduced blood plasma volume,
- impaired oxygen and nutrient transport,
- increased heart rate and body temperature,
- decreased focus and coordination,
- feeling sluggish or weak.
What Should Be in Your Bidon?
The best choice: an isotonic drink or a carbohydrate-based drink with electrolytes.
| Type of Drink (approx. 500 ml) | What It Contains | Use Case |
|---|---|---|
| Water | 0 kcal, no electrolytes | very short training |
| Isotonic drink | ~30 g carbs + sodium, potassium, magnesium | 1.5-3 hours |
| 2:1 drink (glucose/fructose) | 60–80 g carbs/l + electrolytes | 3-5 hours+ |
| Homemade isotonic | water + honey (2 tbsp) + pinch of salt + lemon juice | budget-friendly alternative |
Train your hydration like you train your muscles – you can train your digestive system to tolerate more fluids and carbohydrates during effort.
To sum up: no matter how well you prepare your food for a ride, without enough fluids your body won’t be able to use the energy effectively, and your performance will suffer. Hydration is an integral part of any training or race plan – it requires awareness, preparation, and consistency.
Which Bidon Should You Choose for Cycling? And What Capacity Is Ideal?
Proper hydration starts not only with what you drink – but also what you drink it from. A cycling bidon is an essential tool for any rider, regardless of cycling discipline. If you’re planning rides longer than an hour, it’s best to go with a practical 650 ml capacity – exactly what we offer in the Luxa store.
A Leakproof Bidon That Won’t Spill
Chances are you’ve had your bike frame stained by leaking fluid. A good bidon should be leakproof, ideally with a nozzle that can be switched between open and closed. High-quality bidons (and their valves) keep liquid in control even when the nozzle is technically “open.” It often seems like nothing is leaking – but over hours of training, small drips can escape.
Why a 650 ml Cycling Bidon?
✔️ More than standard, yet still handy – fits easily in your bike’s bottle cage,
✔️ Perfect for 1-1.5h rides – especially in warmer weather,
✔️ Enough space for a full-value isotonic drink (e.g. 30-40 g carbs + electrolytes),
✔️ Easier to manage hydration – 2 bottles = 1.3 liters, enough for up to 2 hours without refilling.
Our Luxa cycling bidons are made from BPA-free, food-safe materials, featuring a high-flow self-sealing valve that won’t leak – even when open. A top-quality bidon should also include a protective coating to prevent unpleasant odors and help keep your bottle clean.
Check out our currently available cycling bottles:
Luxa 650 ml Cycling Bidons
