When the cold weather hits, most runners and cyclists tend to think, “I don’t sweat that much anyway, so why bother with salt intake?” This is the misconception that, during long workouts, insidiously, slowly, almost imperceptibly, destroys energy, concentration, and ultimately the entire day. Sodium is not a privilege of the warm weather. Your body is constantly losing it in the cold – through breathing, evaporation from the skin’s surface, and even through the little bit of sweat that you don’t always notice under your jacket.

However, the majority of athletes only realize it when they are already in trouble: heavy legs, headaches, disintegrating concentration, or that characteristic “all of a sudden my strength is gone” feeling. By then, it is long too late to correct it. The point of sodium replacement is to know in advance how much you are losing – and how much you need to replenish.

Why do most athletes fail to supplement sodium?

Because it's hard to calculate at first glance. If you're just trying to stack mg values, it quickly becomes an overly complicated math problem. The sodium content varies from capsule to capsule, the loss varies depending on the temperature, and everyone sweats differently. That's why someone might suffer more on a long run at 12 degrees than in the summer heat of 30 degrees.

The solution is ultimately not complicated: you need to understand your body's signals and know the one number that decides everything - your sweat rate.

How do you calculate your sweating rate?

This is where most athletes make a mistake without thinking: they underestimate it. However, the method is simple, accurate, and works for everyone.

To calculate your own sweat rate, you first need a scale and a good half-hour of exercise. Weigh yourself before you start. Then, exercise at a steady, moderate intensity for about 30 to 45 minutes. When you're done, dry yourself off—this is very important, otherwise the weight of the water will mess up the calculation—and weigh yourself again.

The difference between the two measurements shows how much water you lost. If you drank during the exercise, you add that to the loss. If you went to the toilet, you subtract that. This number tells you how much you sweat per hour. For example, if you lose 600 grams in 40 minutes, that would be 900 grams in one hour, or 0.9 liters of sweating per hour. This is data on which you can build the logic of sodium replacement very nicely, because you know that you are not talking about numbers that were taken out of thin air, but about the functioning of your own body.

Why isn't it enough to just drink water?

After a while, fluids no longer play a regenerative role, and in fact, if the sodium level is too low, too much water will only further upset the balance. This is where the strange feeling, well known among athletes, comes from: “I drink, I drink, but it gets worse.” The reason for this is that the sodium level in the blood is diluted, and the body is in more and more trouble. It’s not the water that’s missing – it’s the sodium.

Sodium's role is much deeper than that: it maintains the water balance of cells, aids in neuromuscular communication, stabilizes energy levels, and prevents the body from overheating. And in athletes, it also plays a fundamental role in performance: without sodium, thermoregulation does not work, blood plasma volume decreases, and the heart rate increases at the same pace.

Why did we create a separate calculator?

Because all previous calculation methods were too technical, unrealistic or misleading. The Hammer Protocol, however, does not think in terms of mg doses, but in terms of capsules, temperature zones and the individual characteristics of the athlete. The current calculator is based on what has actually been tested by thousands of athletes:

– less sodium is needed in the cold,
– a stable, moderate dose is required during the transitional period,
– it must be raised in warmth,
– in extreme circumstances, a higher dose is unavoidable.

And to all this, we added the amount of sweat you produce, the salt content of your sweat, and the duration of your workout – three factors that can dramatically alter the ideal number of capsules.

How does the calculator work?

It expects only one thing from you: your own data.
Once you have set your sweat rate, sweat salinity, workout length, and temperature, the calculator will first determine the range recommended by Hammer.

There's no trick here: if it's cold, you need fewer capsules, if it's hot, you need more. This is true for all athletes, as temperature is the main factor that determines how much you lose per hour.

However, the calculator doesn't stop there. It compares your own data with the temperature range and tells you which value from the resulting interval is probably ideal for you .
In other words: if you sweat more, or are a saltier type, or exercise in warmer conditions, the system will not leave it up to you to decide, but will gently tip the recommendation towards a higher number of capsules. This is extremely useful in practice: you don't have to guess.

Try our Sodium Calculator here!

Why is it worth running this before every longer workout?

Because your body reacts differently in every situation. A morning run in 10 degrees Celsius will give you a completely different sodium requirement than an afternoon bike ride in 20 degrees Celsius. Not to mention, the recommendation for an athlete who loses 0.6 liters of water per hour is completely different than for someone who loses 1.2 liters in the same amount of time.

Sodium supplementation often doesn't make its effects felt when there's already a problem, but when the athlete suddenly says: "Oops, that was surprisingly easy." This is the result of regularity and conscious adjustment.

Sodium supplementation doesn't add extras – it creates the foundation for performance

Athletes often underestimate how much salt intake matters. Sodium is not a “nice to have” supplement, but rather a fundamental pillar without which nothing works as it should. Performance stability, concentration, and regeneration all depend on proper sodium intake.

And the calculator helps you do what is very difficult to do on your own: find the number of capsules that is ideal for your body, on a given day, under given circumstances.