Are You A Salty Sweater? What Those White Sweat Stains Tell You

On a hot and humid day, there’s one thing that pretty much every runner is guaranteed to experience while putting in the miles: sweating. The sweating response is a thermoregulatory mechanism designed to help cool the body down. 

However, while runners seem to be able to run miles and miles in the heat and barely break a sweat, others will do the same run in the same clothes and be seemingly drenched afterward.

But have you ever finished a run and seen a white residue build-up on the back of your shirt or in the rings of material under your armpits? These salty sweat stains can be a sign that you’re a salty sweater.

But, what exactly does salty sweat indicate? Are there other signs that your sweat is salty besides white sweat stains? 

In this article, we will discuss how to tell if you have salty sweat and tips for salty sweaters to stay hydrated and feel their best.

We will look at: 

• Signs You Are a Salty Sweater

• Does It Matter If Your Sweat Is Salty?

Let’s jump in!

Signs You Are a Salty Sweater

According to research, salty sweat is typically considered to be when your sweat composition is above 70-80 mmol/L. Since most people aren’t able to measure this without fancy lab equipment, here are some of the top signs that you might be a “salty sweater“:

#1: You Get White Sweat Marks On Your Clothes or Skin

If you tend to notice that you get white sweat marks or a white residue on your clothing or skin after running or working out, you’d likely have a saltier sweat than average. Most people will only notice wetness or the liquid portion of sweat on their skin or clothing after exercise. 

A white residue reflects the accumulation of sodium (Na+), which indicates that you have salty sweat.

White sweat residue will be even more pronounced when you are running in dry heat rather than in humid conditions. This is because the liquid portion of sweat will evaporate much faster when it is dry outside. 

Therefore, if you are running in a desert, such as in Arizona, rather than somewhere muggy like Florida, there is a greater likelihood that you will be able to easily detect the presence of more salt in your sweat with white sweat marks.

#2: Your Sweat Tastes Salty

No one voluntarily opts to taste their sweat, but almost all of us have had some sweat from the upper lip drip into the corners of our mouths at one point or another.

Because all sweat contains some amount of sodium, there’s always going to be a bit of a salty taste to sweat. However, if your sweat tastes very salty, it’s a good sign that you are probably a salty sweater.

#3: Your Sweat Stings

When the sweat drips in your eyes or gets into an open cut or area of chafing, you will always experience some amount of burning, again because of the electrolytes in the salt and the pH. 

However, if it’s a pretty intense burning or stinging sensation, it’s a sign that you are losing a lot of salt in your sweat.

#4: You Feel Dizzy When Standing Quickly After Exercise

This one is a bit tricky. If you feel faint or dizzy when you stand up quickly after exercise, it can be a sign that you are a salty sweater. However, it can also be a sign that you are a heavy sweater.

In both cases, when you sweat during exercise, if you lose either a lot of fluid or a lot of salt or both, your blood pressure can drop. 

This can cause orthostatic hypotension or a feeling of lightheadedness or dizziness when you change positions during exercise, especially standing after lying down (think: getting up after doing a bench press or after a bunch of core exercises on a mat once your run is over).

It doesn’t necessarily matter if you are feeling faint or lightheaded because of being a heavy sweater and losing a lot of fluid or being a salty sweater and losing a lot of salt because no matter which factor is predominantly causing your symptoms, you will need to hydrate more aggressively and with more electrolytes.

#5: You Get Muscle Cramps

The association between muscle cramps during exercise and electrolyte imbalances or sweat loss is not yet well understood or necessarily definitively demonstrated in research. 

However, there is a lot of anecdotal evidence to suggest that your risk of getting muscle cramps when you work out may be higher when your sodium levels are low. 

Thus, if you seem to be prone to Charlie horses or other muscle cramps during or after exercise, you might be losing an excessive amount of salt in your sweat.

#6: You Crave Salty Food After Exercise

Sodium is one of the nutrients that the body will crave when your levels are low. 

If you find yourself thinking about salty foods or wanting salty foods during or after exercise, it’s likely that your body is sending you a message that your sodium levels are low and you need some salt to restore homeostasis.

Pay attention to your cravings, as this is a likely sign that you have salty sweat.

Does It Matter If Your Sweat Is Salty?

So, let’s say you are always finding salty sweat stains and feel salty sweat burning your eyes when you work out.

Does it matter? Do you need to be concerned about having salty sweat?

Being a salty sweater isn’t inherently an issue, but it is an important consideration when you are determining your hydration needs before, during, and after exercise.

Essentially, when it comes to your hydration needs in relation to exercise, there are two aspects of sweat that you need to think about: your sweat rate (how much do you sweat?) and the composition of your sweat (how salty is your sweat?).

Let’s consider both of these.

Sweat Rate

Although everyone sweats when they exercise, we all have a slightly different sweat rates.

In other words, someone might be a “heavy sweater,“ which means that they have a high sweat rate and lose a lot of fluid through sweat.

Hyperhidrosis, which is a condition marked by excessive sweating, requires deliberately drinking more fluid before, during, and after exercise (as well as throughout the day) to help maintain proper hydration levels and replace fluids lost in sweat.

There are different ways to measure your sweat rate, but the simplest method of approximating how much you sweat during a workout is to weigh yourself before the workout without any clothes on and then weigh yourself after the workout without any clothes on.

The reason it is important to take your clothes off is that after your workout if you do not remove your sweaty clothes, you will not be able to accurately assess how much fluid weight was lost. 

You also need to weigh yourself without clothes before the run so to keep the conditions balanced.

Note that there is nothing inherently wrong with drinking more than your sweat rate as long as you are taking in enough electrolytes so that you do not overly dilute the electrolyte concentration in your body.

Runners can be at risk of hyponatremia, which refers to low sodium levels, if they drink too much plain water and lose too much salt in their sweat. If sodium levels are not quickly resolved or if hyponatremia is severe, it can be extremely dangerous and result in cardiac arrhythmias, seizures, coma, and even death.

Sweat Composition

Although many athletes really only focus on the sweat rate or the fluid lost aspect of sweating during exercise when trying to determine hydration needs, it can be equally important to consider the composition of your sweat, especially in cases where you are a salty sweater.

Ultimately, if you are a salty sweater or you have salty sweat, you need to be more aggressive in replacing electrolytes during and after exercise. It won’t be enough to drink just plain water unless your workout is very short and you have eaten something salty prior to exercising. 

Instead, you will want to ensure that you are having electrolytes in your fluids, either as a pre-made sports beverage or by adding salt tablets to your water.

With that said, most electrolyte beverages and sports drinks only provide the proper sodium level for regular sweaters. If you have salty sweat, you will need to take in more sodium, which is where salt tablets or adding more salt to your fluids and fueling foods will be beneficial.

You can also add salt to your food before and after exercise to help counteract the salt lost in sweat.

For more information on hydration and electrolytes, check out our guide: Fluid and Electrolytes: A Complete Runners’ Guide.