In this article, you'll learn how to recognize your fluid loss, how much you should really drink, and how to optimally rehydrate after your ride.
Why fluids are so important when cycling
When you sweat, you lose not only water but also electrolytes like sodium, potassium, and magnesium. Even a 2% weight loss through sweating can lead to the following problems:
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Reduced endurance performance
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Increased heart rate with the same load
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Concentration problems
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Cramps or headaches
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increased risk of overheating
So if you want to stay productive, you shouldn’t just drink “sometime” – but strategically and regularly.
How much fluid do you actually lose?
This depends on temperature, intensity, duration, and personal sweating rate. As a rule of thumb:
Depending on the conditions, you lose between 0.5 and 1.5 liters per hour when cycling on a road bike.
If you want to know exactly, you can determine your sweat rate like this:
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Weigh before the trip (naked)
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Driving (without drinking)
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Then weigh
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1 kg weight loss = 1 liter sweat loss
Tip: Test this on a warm day during moderate exercise – this will give you a guideline for your fluid needs.
How much should you drink?
The goal is to compensate for as much of the fluid loss as possible – without overtaxing the stomach.
Rule of thumb for long trips (>90 minutes):
Important: Don't wait until you're thirsty! The feeling of thirst lags behind your actual need—especially during exercise.
What should you drink?
Plain water is often not enough, especially on longer tours. A good sports drink contains:
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Water (liquid carrier)
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Carbohydrates (approx. 6–8%) for energy supply
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Sodium (600–800 mg/l) to improve water retention
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Optional: magnesium, potassium, calcium
Example of a simple DIY sports drink:
Pay attention to the osmolality — how quickly your drink is absorbed. Isotonic drinks are particularly effective because they have the same osmotic pressure as your blood.
Signs of dehydration
You may already be dehydrated if:
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your urine is dark yellow
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you have to go to the toilet less often
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you get a headache
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your legs feel “empty”
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you get chills or goosebumps (warning signs!)
The sooner you take countermeasures, the better.
Rehydrate after the ride
Rehydrating after exercise is just as important as drinking during the ride – especially on hot days or after several training days in a row.
Goal:
Compensate for fluid deficit plus about 25% extra to compensate for losses through urine.
Example:
If you have lost 1 kg = drink 1 liter + 250 ml extra → 1.25 liters of rehydration
Best suited:
Special case: Drinking in competition
Drinking regularly is often more difficult during a race – due to high intensity, nervousness, or focus on the course. Therefore:
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Mark bottles beforehand (e.g. with Edding) for better timing
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Mentally incorporate drinking intervals (e.g. a sip every 15 minutes)
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For short races (<60 minutes) one small bottle of electrolytes is often sufficient
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For long races (>2 hours): 2 bottles with carbohydrates + salt, plan for refills if necessary
Tip: Practice drinking during training! If you can drink with one hand at 40 km/h, you'll be more relaxed during the race.
The most common mistakes when drinking
❌ Only drink when you are thirsty
❌ Only water – no electrolytes
❌ Drinking too much at once
❌ Not knowing how much you are actually losing
❌ Forgetting to rehydrate after the ride
Conclusion: Hydration is your turbo
Drinking isn't an afterthought — it's the number one performance factor. Those who drink regularly ride better, recover faster, and feel more confident on the bike. Pay attention to your signals, always have enough fluids with you—and practice your drinking habits just as you practice your acceleration on the climb.
Because sometimes it's not the strength of your calves that determines your performance – but the contents of your water bottle.
Bonus: Checklist for your next trip
✅ Two full bottles of 750 ml each for tours > 2 hours
✅ Add electrolytes or isotonic drink
✅ Start well hydrated beforehand
✅ Drink every 15–20 minutes
✅ After the ride: Weigh + rehydrate
