For over 15 years, MULEBAR has supported athletes in their pursuit of natural performance. In this guide, learn how to prepare an effective and economical homemade isotonic drink using simple ingredients you most likely already have in your cupboards. We reveal the precise measurements for an anti-cramp drink rich in electrolytes, tips for customizing your energy drink according to your sport, and all the secrets to perfect hydration during exercise.
1-Isotonic drinks and hydration during exercise
Properly hydrating the body is essential for every athlete concerned with performance. Isotonic drinks offer a carefully balanced combination of electrolytes and carbohydrates, similar to our blood plasma, enabling optimal absorption. Much more than flavored water, their carefully formulated recipe makes them true energy allies.
Why an isotonic drink helps with hydration
Unlike plain water, a homemade isotonic drink is absorbed more efficiently thanks to its specific components. Sodium activates intestinal transport through the sodium-glucose system, thereby accelerating the arrival of nutrients in the bloodstream. This mechanism explains why athletes experience better hydration with less digestive discomfort.
Its composition perfectly restores water and mineral losses. During exercise, we lose between 500 and 2000mg of sodium per hour depending on the intensity. Without adequate intake, dehydration sets in, reducing blood volume and limiting muscle performance.
- Fast absorption: Sodium promotes the passage of water and carbohydrates through the intestines.
- Lasting performance: The simultaneous intake of water and electrolytes prevents dips in performance.
- Guaranteed comfort: An appropriate osmotic concentration prevents digestive problems.
The ideal temperature is between 10 and 15°C. This range optimizes absorption while providing a pleasant feeling of freshness. If too cold, the drink may cause cramps; if too warm, it is less easily assimilated.
Simple recipe and key measurements
Our signature recipe for 500ml: 500ml of water, 20g of honey, one tablespoon of lemon juice, and 1g of sea salt. This preparation provides approximately 17g of carbohydrates, 23.5 mg of potassium, and natural antioxidants.
Honey is particularly beneficial thanks to its natural blend of glucose and fructose. Its enzymes aid digestion, while its polyphenols protect against oxidative stress.
Adjust according to heat and intensity
Adjust the concentration according to the conditions. In hot weather, prioritize hydration by limiting carbohydrates to 30g/litre. Conversely, for prolonged exertion or in cold weather, you can increase it to 70g/litre without impairing absorption.
The rate of consumption is crucial: 350 to 500ml per hour, in small, regular sips. Do not wait until you are thirsty, as this is a sign that dehydration has already begun.
2-Isotonic recipe and variables to master
Creating an effective isotonic drink requires understanding a few fundamental physiological principles. The goal is to reach an osmolality of 270 to 330 mOsm/kg, which enables optimal absorption while avoiding digestive problems. Since this value corresponds precisely to that of our body fluids, it creates the desired isotonic effect.
The right percentages for hydration
The balance between sodium and potassium is crucial for optimal hydration. Sodium controls the volume of fluid outside the cells, while potassium acts inside them. The right ratio facilitates fluid transfer and protects the integrity of cell membranes.
For one litre of drink, aim for these ideal proportions:
- 40 to 80g of carbohydrates (i.e. 4-8%)
- 500 to 700mg of sodium
- At least 300mg of potassium
These amounts promote optimal intestinal absorption while compensating for losses caused by sweating. However, avoid excess, which could upset the balance of your preparation.
Key points to remember
- Ideal carbohydrate concentration: 6% represents the best compromise between available energy and absorption speed for athletes.
- Minimum sodium threshold: Below 460mg/L, hydration becomes considerably less effective.
- Digestive limit: Above 8% carbohydrates, the risk of discomfort (nausea, bloating) increases significantly.
- Practical tip: Use lukewarm water (35°C maximum) to dissolve the honey more easily while preserving its enzymes and antioxidants.
The choice of water is essential: mineral-rich water naturally provides calcium and magnesium, which are essential for proper muscle function. This natural solution avoids additives while improving the nutritional quality of your drink.
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Hépar → approx. 555 mg/L of calcium + 119 mg/L of magnesium.
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Contrex → approx. 486 mg/L of calcium + 84 mg/L of magnesium.
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Courmayeur → approx. 576 mg/L of calcium + 90 mg/L of magnesium.
Optimized honey-lemon recipe
For one litre of effective energy drink: mix 3 tablespoons of flower honey, the juice of one lemon, and 1/4 teaspoon of salt into water. This recipe perfectly matches honey’s natural glucose-to-fructose ratio, enabling optimal carbohydrate use—up to 90g per hour for trained athletes.
Tip: the type of honey affects energy release. Acacia honey (GI 53) is ideal before exercise, while honey with a higher glycemic index is preferable during activity for an immediate energy boost.
3-Preventing muscle cramps
Cramps most often occur when the body loses too much sodium and potassium through sweating without sufficient replacement. Several signs should alert you: white marks on your clothing, early cramps during exercise, or unusual muscle fatigue. These are classic indicators of an electrolyte imbalance.
Potassium plays a key role here: it supports neuromuscular and cardiac function, complementing sodium. To make your homemade isotonic drink more effective against cramps, add 1/4 teaspoon of potassium chloride per liter, in addition to your usual salt. This addition is particularly useful during prolonged exercise or in hot weather, when mineral losses accelerate.
Anticipate rather than react: start hydrating and replenishing electrolytes from the beginning of your effort, without waiting for the first signs of cramping—by then, the imbalance has already set in.
4- Homemade electrolyte drink: the right amounts
An effective isotonic drink is based above all on a good balance of electrolytes, especially sodium and potassium. Sodium regulates fluid volume outside the cells, while potassium acts inside them: together, they optimize fluid transfer and protect muscle integrity.
For one liter of homemade electrolyte drink, aim for these guidelines:
- 500 to 700mg of sodium
- At least 300mg of potassium
- Below 460 mg/L of sodium, hydration becomes significantly less effective
For consumption, follow this schedule for optimal absorption:
- Approximately 200 to 300ml about 30 minutes before exercise, for pre-hydration
- Regular, spaced-out sips during activity, as the stomach can absorb only about 800ml per hour
- 500 to 700ml within the hour following exercise, for recovery
Mineral water rich in calcium and magnesium, such as Hépar or Contrex, naturally complements your electrolyte intake without the need for additives.
5-Isotonic recipe by type of effort
Each sport requires a customized hydration and energy-intake strategy. The intensity and duration of your effort, along with the weather conditions, determine the perfect recipe for your isotonic drink. By customizing your mix, you maximize its benefits for your performance while preserving digestive comfort.
Short sessions and hot weather
For a trail running or cycling session lasting less than 2 hours in hot weather, choose a homemade isotonic drink that is light in carbohydrates. A simple mixture of 30g of sugar and a pinch of salt in 1L of water, optionally flavored with a light infusion, will work perfectly. This formula prioritizes hydration over a massive energy supply.
A moderate carbohydrate content facilitates absorption in the stomach, which is particularly important when your body is struggling with heat. Less concentrated solutions are better tolerated during intense exercise, thereby reducing the risk of digestive issues. A real advantage during summer events, when thermal management becomes crucial.
This comparison details the different types of drinks (hypotonic, isotonic, hypertonic), explains why plain water is not enough during exercise, and provides all the keys to preparing your ideal drink: an electrolyte balance close to that of plasma, recommended amounts of sodium, potassium and magnesium, the presence of B vitamins, and the right amount of sugar.
Long trail running and cycling outings
For efforts lasting more than 2 hours, your body requires a continuous energy supply. Combine 30-40g of maltodextrin with 30-70g of sugar per liter, adjusting according to the outside temperature. Maltodextrin provides progressive energy without altering the taste, making it perfect for long distances in trail running or cycling.
This ingenious mixture activates several intestinal absorption pathways. Maltodextrin gradually converts into glucose for sustained energy, while sugar provides immediate support. This synergy allows you to maintain your effort without experiencing a drop in performance.
Diluted gel hydration tip
A practical solution: dilute a tube of energy gel in 500ml of water . This instantly gives you a perfectly balanced homemade isotonic drink when aid stations only offer water. The concentration precisely meets your physiological needs.
This method combines simplicity and effectiveness. Since the gels are already balanced in carbohydrates and electrolytes, diluting them preserves these optimal proportions. Ideal if you usually use a well-tolerated gel brand, ensuring comfortable absorption.
6-Varied isotonic recipe and optimal hydration
Regularly changing the flavors of your drinks helps prevent monotony during prolonged exercise. Our homemade recipes retain all the essential isotonic properties while offering pleasant taste variations. This diversity encourages more consistent hydration, which is crucial for performing at your best.
Natural flavor ideas
Maple syrup is an interesting alternative to honey, with a slightly different carbohydrate profile. For one liter of water, mix 2 tablespoons of maple syrup with a tablespoon of sugar. Add the juice of half a lemon, 1/4 teaspoon of salt, and a pinch of baking soda to balance the acidity.
Orange juice provides natural vitamins and antioxidants. Prepare a half-and-half mixture of pure juice and water, with a spoonful of sugar and salt. This recipe harnesses the fruit’s natural carbohydrates while maintaining an excellent isotonic balance.
In hot weather, opt for a formula richer in mineral salts. Use lime juice, 1/4 teaspoon of regular salt, and 1/4 teaspoon of potassium-enriched salt. Sugar is optional; the key is to effectively replace lost electrolytes.
Baking soda and acidity management
Baking soda is particularly useful for grape juice-based preparations. Use 700 ml of water, 300 ml of grape juice, 30 g of maltodextrin, and salt. A pinch of baking soda improves digestive comfort and prevents acid-related discomfort.
Baking soda has two major benefits: it buffers the acidity of fruit and reduces muscle acidosis. But use it in moderation—a pinch per liter is more than enough; using more could cause digestive problems.
This tip is ideal for athletes who are sensitive to acidic drinks. Baking soda transforms a potentially irritating preparation into a perfectly tolerated isotonic drink. Always test this version during training before using it in competition.
7-Isotonic drinks: successful and safe hydration
To create an effective isotonic drink, you need to understand a few key physiological principles. This basic knowledge will help you avoid common mistakes that affect performance or cause digestive problems.
Key figures and quick recipe
Our homemade energy drink recipe for one liter of water consists of: 3 tablespoons of flower honey (providing 63 g of carbohydrates), 1/4 teaspoon of salt (providing 575 mg of sodium), and the juice of one whole lemon. This carefully balanced mixture precisely meets the recommended osmolality while providing the essential minerals needed during exercise.
- Ease of preparation: It only takes 2 minutes to make this drink. Use lukewarm water to help the honey dissolve.
- Storage: Keep it refrigerated for a maximum of 24 hours, but for optimal effectiveness, consume it within 4 hours.
- Value for money: At just €0.30 per liter, this homemade alternative is far more economical than commercial drinks (€2 to €4 per liter).
You can adjust the proportions according to your specific needs. Athletes with sensitive digestive systems should reduce the honey to 2 tablespoons, while ultra-endurance athletes can use up to 4 tablespoons. Experiment with different concentrations during training to find your perfect balance.
| Ingredient | Quantity for 1 L | Nutritional contribution | Physiological function |
| Floral honey | 3 tbsp (63 g) | Various carbohydrates | Provides rapid and sustained energy |
| Sea salt | 1/4 tsp | 575 mg sodium | Optimizes water absorption |
| Lemon juice | 1 whole lemon | Vitamin C, acidity | Antioxidant action and flavor enhancer |
| Mineral water | 1 liter | Calcium, magnesium | Hydrating base and source of minerals |
Hydration plan and digestive tolerance
The ideal osmolality is between 270 and 330 mOsm/kg for optimal intestinal absorption. An overly concentrated mixture slows digestion and may cause cramps, while excessive dilution reduces energy intake during exercise.
How to consume your homemade electrolytes properly:
- Approximately 200 to 300 ml about 30 minutes before exercise for effective pre-hydration.
- During activity, choose spaced-out sips rather than large quantities at once.
- Your stomach can assimilate only about 800 ml per hour.
For recovery, drink 500 to 700 ml within the hour following exercise to replenish your water and electrolyte stores. A ratio of 1 part protein to 4 parts carbohydrates will also optimize muscle repair.
If you do not have time to prepare your own isotonic drink, we recommend our Mulebar sports drinks.
- Red berry sports drink
- Citrus sports drink
- Red berry hydration drink
- Citrus hydration drink
Also consult the comparative guide to the best isotonic sports drinks and the comparative guide to the best hydration drinks to find out which brands on the market have the best dosages.
In March 2026, Mulebar’s two sports drinks were ranked joint first for quality in a comparative panel of 45 brands by nutritionist Nicolas Aubineau. They rank second for value for money behind Decathlon; it is difficult to do better than them given the volumes they produce.
