Learn your unique hydration needs
Not all sweat is created equal — sodium loss can range from under 400 mg/L to over 2000 mg/L. Knowing your sweat sodium concentration is the missing link to dialing in a truly personalized hydration strategy.
Similar Athletes, Different Hydration Needs?
It doesn’t take much effort for the body to start sweating once activity begins. Humans gained a huge evolutionary advantage from this mechanism: sweating allows us to regulate body temperature and sustain endurance over long periods.
Sweat itself — specifically the moisture on our skin — is the key ingredient for evaporative cooling, which wicks heat away and helps us keep moving at a strong pace.
Not All Sweat Is the Same
While sweating is universal, how much sodium each person loses in sweat varies enormously. The average sweat sodium concentration is around 950 mg per liter, but the range stretches from as low as 200 mg/L to more than 2000 mg/L — a tenfold difference between individuals.
This means that even athletes of similar fitness levels and body types can have completely different hydration needs. No single sports drink or product can cover everyone all of the time. The key is understanding your own physiology.
Why Testing Matters
The Advanced Sweat Test from Precision Hydration measures your exact sweat sodium concentration. When combined with sweat rate data in different conditions, this gives athletes a powerful blueprint for tailoring fluid and sodium intake during training and racing.
Let’s look at an example.
Case Study: Jacob vs. Steve
Both athletes are of similar ability and body weight, competing in the same event. See how their sweat sodium concentration, sweat rates (tested in conditions similar to race pace and weather) add up to very different intake needs on race day.
👉 Steve needs to consume a hydration mix higher in sodium, and consume more of it to keep fluid and sodium balances in check.
In a short event (1–2 hours), both athletes might perform similarly even if they drank the same sports drink, as the body can regulate a fair amount of losses. But in longer or hotter races, Steve would likely struggle as his fluid and sodium losses pile up, leading to fatigue or even dangerous drops in performance.
Building a Smarter Plan
The goal for each athlete is to find a hydration and fueling strategy that:
Consume a hydration mix that is similar to your sweat sodium concentration in order to maintain Balance
Have a sense of your sweat rate and consume the determined hydration mix in the appropriate quantities to avoid problematic blood volume losses (3% is a goal)
Have fueling strategies that work with your hydration plan, logistics, and preferences
There’s no universal formula. A good plan starts with personal data, the right building blocks, and the flexibility to adjust as needed.
FAQs
Q: How many times do I need the Advanced Sweat Test? Do sodium levels change?
A: Just once. Your sodium concentration is genetically influenced and remains fairly stable, with only minor fluctuations.
Q: Isn’t sodium bad for you?
A: In excess, yes — but too little is just as harmful. Your body tightly regulates sodium in the blood, and low sodium during prolonged exercise in the heat can cause hyponatremia, a dangerous condition. Testing ensures you stay in balance.
Q: What about other electrolytes in sweat?
A: Sweat also contains potassium, magnesium, calcium, and chloride. However, these losses are smaller and more consistent between individuals compared to sodium.
Q: How much does the Advanced Sweat Test cost?
A: The in-clinic test costs $150. Home visits and group discounts are also available — contact us for details.