Published on July 3, 2026 03:00 am
Whether you’re training for a 5K or covering countless miles to prepare for a marathon, all runners, athletes, and outdoor enthusiasts have one thing in common: sweat. While we are all subject to droplets of sweat dripping from our forehead, sweating is not the same for everyone. Some people hardly notice it, while others finish a workout or hike completely drenched. And then there are salty sweaters: ones that appear to have white streaks on them and can feel the salt and sweat on their clothes and skin. If this sounds like you, your sweat is likely high in sodium.
The good news is that losing salt in sweat is completely normal. But it can affect the way you fuel and hydrate after your workout. Here, Emily Burgess HorvathA registered dietitian for USA Track & Field and the Hospital for Special Surgery, Gives us the details on why sweat is salty, signs that your sweat is primarily salty, and how it affects your workout preparation.
What causes salty sweat in runners?
Burgess Horvath explains that you sweat to regulate your body temperature. When you exercise, your core body temperature increases, and sweating allows your body to cool itself.
“As sweat evaporates from the skin, it dissipates heat and helps maintain thermal balance,” she says. “This is especially important during endurance exercise, hot weather, or high humidity when thermal regulation in the body may be challenged.” (FYI: Your body’s thermal balance is its ability to maintain a steady internal temperature despite external temperature changes.)
Understanding how much you sweat and what’s actually in your sweat can help you tailor your hydration and fueling strategies to prevent dehydration, hyponatremia (when sodium levels in your blood are too low), and fatigue during your training, explains Burgess Horvath.
She says the amount of sodium in sweat can vary from person to person – ranging from about 200 milligrams per liter to over 1,000 milligrams per liter. It depends on factors such as age, gender, aerobic fitness, hydration status and environmental conditions. According to a 2022 study In Journal of Applied Physiology.
“This variation means that some athletes will lose much more electrolytes than others – not just sodium – and drinking water alone will not be enough to maintain that electrolyte balance,” says Burgess Horvath. “So knowing your sweat profile – salty sweater versus light sweater – can guide decisions about electrolyte intake before, during and after exercise, the amount of fluid needed day-to-day, and any recovery practices.” (More on this in the upcoming sections)
4 signs you’re a salty sweater
According to Burgess Horvath, you’ll usually be able to tell whether your sweat is primarily salty based on the following indicators.
1. Your sweat tastes salty
“One of the most common signs I typically see in exercise is definitely the taste of salt within your sweat, like when it hits your lips during exercise,” says Burgess Horvath.
2. Your eyes burn
This race isn’t going to make you cry; This is the salt from your sweat getting into your eyes. (Granted, it could be sunscreen or mascara, so pay attention to other signs.)
3. You see white stains on your clothes
Look for white chalky stains or layers on your workout clothes, such as your shirt or the inside of your hat, according to Burgess Horvath, another sign that your sweat is too salty. You’ll also probably notice white salt lines on your skin after you run.
4. You often have muscle cramps
Muscle cramps, especially in hot and humid conditions, are another sign that your sweat is salty, says Burgess Horvath. Losing sodium (an electrolyte) through your sweat causes your muscles to become stiff and crampy.
It’s important to note that muscle cramps can also be the result of many other factors, such as dehydration, overexertion or fatigue, circulatory problems, medications, and other medical conditions, so it’s important to talk to your doctor if you experience them regularly.
Hydration and Refueling Strategies After Massive Sodium Loss
Losing too much sodium through your sweat can cause health problems like nausea and vomiting, headaches, fatigue, muscle weakness or cramps, confusion, irritability and even seizures or coma. Mayo Clinic. Burgess Horvath explains that it’s important to carefully plan your hydration and fueling strategy before, during, and after a race to avoid excessive sodium loss. In an ideal world, you would consult with a sports dietitian to create a strategy tailored to your needs. But these tips can help you with basic fuel planning.
Pay attention to carb intake
Burgess Horvath emphasizes the importance of carbs because they increase fluid absorption and promote better fluid retention. She suggests consuming 30 to 60 grams of carbs about 45 minutes before running. (For example, a banana has about 30 grams of carbs.) During your race, she recommends consuming at least 60 grams of carbs per hour. After a race, she says to aim for a 2 to 1 ratio of carbs to protein — for example, 20 grams of protein with 40 grams of carbs.
Eat sodium-rich foods
That’s right, it is allowed to eat more salt. Burgess Horvath recommends consuming sodium-rich foods, such as pretzels, or electrolyte sports drinks that contain sodium before, during, and after your run. the current Dietary Guidelines for Americans Adults are recommended to consume no more than 2,300 mg of sodium a day. However, athletes who wear heavy sweaters and exercise several hours a day—say, run a four-hour marathon—may need up to 3,500 milligrams of sodium per day. according to an article In current sports medicine report.
Turn to electrolytes after high-intensity sessions
Finally, it’s important to stay on top of your hydration — not just on days you go running, but day after day. “You don’t want to be playing catch-up when it comes to training or competition,” says Burgess Horvath.
An easy way to check your hydration status throughout the day is to assess the color of your urine, she says. The darker and yellower your urine, the more dehydrated you are, According to a 2020 article In marginal nutrition. On the other hand, passing light and clear urine indicates that you are hydrated.
“The goal is to replace fluid loss, but not exceed that,” says Burgess Horvath. “You may have heard on average that body weight is lost no more than two percent during training or exercise. So using a sports drink or hydration supplement with adequate sodium and carbs can be a great way to help with this.”
Burgess Horvath says the general rule of thumb is to stay hydrated with water for runs or other workouts less than 45 minutes and supplement with electrolytes for longer runs. By weighing yourself before and after running, you can usually find out how much fluid you have lost during your run. Be sure to rehydrate with fluids and electrolytes to replace about 120 to 150 percent of the fluids you lose during exercise. And that could just be your regular meal – having something like soup or adding table salt to a meal that has a 2 to 1 ratio of carbs to protein.
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