Sweat Testing Questions

/Sweat Testing Questions

Where do I send my Sweat Test sample?

  1. Mail the completed information card & sweat sample back to us in the provided return mailer. Take a picture of the tracking label, in case your sample gets lost in the mail.
  2. If you lost the mailer, make sure to send your sample in a padded envelope to protect the vial, and send via USPS to:

HEAT Sport Sciences, Inc.
Attn: Dr. Sandra Fowkes-Godek
P.O. Box 327
Pocopson, PA 19366-0327

Please get a tracking number and let us know that your sample is coming (testing@levelen.com).

What is a Simulated Sweat Test? How Does LEVELEN’s Test Differ?

Stimulated sweat tests are static tests that are medically approved for detecting Cystic Fibrosis. The problem with this method, in terms of athletic performance, is that the sweat composition generated by an artificial stimulus differs greatly from a true sample taken during physical activity. Eccrine sweat glands are stimulated when the body is hot (physical activity), and sweat produced by eccrine glands will have different electrolyte levels from aprocrine glands. Numerous studies have shown that this stimulated method results in elevated levels of electrolyte concentration,

Why Should I Get A Sweat Test?

Based on over 15 years of research, and data on thousands of athletes across numerous sports, athletes simply don’t sweat the same. General hydration guidelines are just that, general, and aren’t useful for helping the athlete determine their unique fluid and electrolyte needs. Your Sweat Profile is uniquely yours, and could differ dramatically from another (over a hundred fold), even if they have a similar diet, body type, size, etc.

My Blood Test says I’m “normal”, why do I need a Sweat Test?

When it comes to electrolytes, your body is very good at regulating your levels. Usually within an hour, your sodium and chloride levels will have returned to normal levels, even after suffering muscle cramps during competition. Our sweat test determines what your real-time losses will be, so we can scientifically replenish based on your specific needs and assure your levels will never drop below normal during an event. A blood test does not provide the real-time information needed to determine an individual’s specific fluid and electrolyte needs.

How Much Does Sweat Vary Between Athletes?


The amount of sweat volume (rate of fluids lost) can vary greatly from one athlete to another, over a 37-fold difference. While sweat rate is slightly correlated to size (larger athletes typically sweat more) and gender (males sweat more than females), two athletes of similar size and gender can have very different sweat volumes. That is why sweat testing is critical for determining your exact fluid and electrolyte replenishment needs to maintain peak performance.

Does My Sweat Profile Change? How Often Should I Test?

Year over year: If you were tested today, and the same time last year…our studies indicate your results would be the same. The test is very accurate and allows for precise recommendations of your customized electrolyte replenishment solution. However, if your diet, weight, medications or level of activity change dramatically, this could affect your sweat composition. We recommend re-testing annually to ensure accurate recommendations of LEVELEN products.

Season to season: As the weather warms and cools,

How Do I Perform a Sweat Test?

Just like elite professional & collegiate teams and athletes, you can now determine your unique sweat profile (sweat rate & electrolyte loss), and end the electrolyte replenishment guessing game. Our LEVELEN Electrolyte Replenishment System (ERS™) is the only integrated solution of sweat testing and electrolyte replenishment products customized to your needs.

The video below details how to perform a self-administered sweat test. Once we receive your test sample and analyze it,

What Do You Test For?

The Sweat Test measures your sweat volume (sweat rate) and sweat composition (electrolyte concentrations). Both measurements are instrumental in understanding how your body reacts to exertion and what specific replenishment you need to maintain proper electrolyte balance under physical stress, as well as preventing heat-related illness.

Electrolytes measured: Sodium (Na+), Potassium (K+), Chloride (Cl-)

Based on your results, we determine the amount of electrolytes lost in sweat that need to be replenished, down to the milligram.

Why Do I Need to Weigh Myself?

Sweat Rate. In order for us to get an accurate measurement of your sweat volume, it is important to weigh yourself both before and after the duration of your workout. Since sweat can be absorbed in your clothing, you should weigh yourself with minimal/no clothing. For the post-workout weight, please wipe off any sweat before weighing out. Your workout should ideally last for an hour.

The difference in your weight before & after your workout is the total amount of fluid lost in your sweat when you exercise.

Why Do I Measure How Much I Drink?

Sweat Rate. In order for us to get an accurate measurement of your sweat volume, we need to determine how much you consume during your workout. The amount of fluid you consume will affect your post-workout weight.

During the test, if possible, we recommend not drinking any fluids. This allows us to attain the most accurate reading of your sweat rate/volume.  We recognize that hydration may make you more comfortable during your workout,