The calories the sweat glands burn just to make sweat are minimal. When you sweat, you may lose a bit of weight due to water loss, but that weight is restored when you rehydrate.
Physical exertion and the body’s response to heat are the main factors that cause sweating. You may sweat more with more intense exercise, but how much you sweat is highly variable, depending on several factors.
This article describes how sweating correlates with burning calories and weight loss.
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What Does Sweating Do?
There are a few different reasons why your body sweats. When you’re too hot, your body produces sweat so that you can cool off. Sweating while exercising helps the body regulate its temperature.
If the temperature around you is too hot, or if you have a fever, your body responds by triggering your sweat glands to send water and minerals to the surface of your skin.
Similarly, when you exercise, your body temperature rises—and your sweat glands release water and minerals on your skin. The water on the outside of your body evaporates to cool you down, making you more comfortable and protecting you from overheating.
Other Causes of Sweating
Thermoregulation, which is your body’s temperature control, is the main reason for sweating. However, researchers are exploring whether sweating might have other benefits besides thermoregulation.
Sweat is also produced in response to factors other than temperature, such as body position, pain, fluid concentration in your body, hormonal shifts, muscle use, and outside environment factors (such as altitude).
Other factors besides overheating can also stimulate sweat. Anxiety, embarrassment, certain medications, and spicy food can trigger sweating because they activate chemicals throughout the body that quickly affect your sweat glands.
However, it’s not clear whether sweating in these situations actually benefits health or is just a side effect of the physiological changes occurring.
Some scientists have suggested that sweating might help cleanse toxins from your body, but the evidence is weak. So far, conclusions indicate that toxin removal through sweating is not as well controlled or as effective as toxin cleansing through the kidneys (urinating, or peeing) or from the colon (defecating, or pooping).
Do You Burn Calories Sweating Without Exercise?
Weight loss can occur when you use more calories than you take in. This is called a calorie deficit. The body must burn available energy sources, such as stored sugars and fat, for both basic functions (including thermoregulation) and physical activity.
The natural ways to lose weight are to move more, increase the intensity of physical activity, or eat fewer calories. It usually takes a combination of these strategies to lose weight.
Can You Sweat in a Sauna for Weight Loss?
Using a sauna for potential health benefits can be enjoyable, but the bottom line is that sweating in a sauna hasn’t been shown to burn calories or help you lose weight. Studies show that people can lose a small amount of body weight after using a sauna, but this has been attributed to fluid loss—not loss of fat or burning calories.
If you enjoy using a sauna, keep a few health considerations in mind. You will sweat in a sauna and lose body fluid, so you must stay hydrated. Drinking water when sitting in a sauna can help compensate for the water loss.
Extended sauna sessions (more than 15 to 20 minutes) can lead to overheating. This can make you tired and can even have serious health consequences. Discuss using a sauna with a healthcare provider if you have an ongoing medical condition, especially one that makes you sensitive to heat, and ask about ways to use one safely for hygiene reasons, such as by sitting on a towel.
Illness, Sweating, and Weight Loss
If you develop a fever due to illness—usually a viral or bacterial infection—you might sweat due to the fever as your body tries to fight the infection and cool down. Staying hydrated when you have a fever is important.
When sick, you might lose weight from fluid loss (including sweat, diarrhea, and vomiting), changes in eating, and increased metabolism when fighting the infection.
Making Sweat Consumes Negligible Calories
Sweating doesn’t specifically help you lose weight. All physical processes in your body use up calories, and that includes sweating. But medical experts have concluded that it doesn’t take a lot of calories for your body to make sweat.
Does Sweating With Exercise Mean You Are Burning More Calories?
Generally, higher-intensity exercise causes you to sweat more because the metabolic process of using calories to exercise creates body heat—which triggers sweating. So, sweating with exercise generally reflects that you are burning more calories.
Other indicators of physical exertion during exercise include increased heart rate, faster breathing, deeper breathing, and not feeling like it’s easy to talk.
But all signs of intense exercise are highly individualized, including sweat. Some people sweat much more than others, and you may feel sweaty due to humidity, heat, and other environmental factors.
Research also shows that an individual’s degree of sweating can change with conditioning and exercise. Over time, your sweat glands can increase in size and become more sensitive, causing you to sweat more when you exercise as you become more physically fit.
Does Sweating Help You Lose Weight?
When you sweat, you temporarily lose water weight. Sweating alone has no effect on body fat, and the weight loss from sweat other than from water loss is practically negligible. But engaging in physical activity that makes you sweat can burn a lot of calories, helping you build muscle and lose fat.
Staying Healthy When You Are Sweating
It’s important to stay healthy when you’re sweating. If you anticipate sweating due to an activity you’ve planned, it’s a good idea to have a drink handy so you can replenish and avoid getting dehydrated.
Dehydration from sweating means that you’ve lost too much fluid. Dehydration causes dizziness, headaches, and can even cause you to faint.
Sweating can also disrupt the balance of charged minerals (electrolytes) in your body—these include sodium, potassium, calcium, and magnesium—which can affect the your body’s functions. Symptoms may include muscle cramps and muscle spasms, slow or rapid heart rate, shortness of breath, or seizures.
If you are exercising and sweating for more than an hour, you may want to replenish with an electrolyte drink.
Exercise is healthy, but exercising more than you can handle can increase the risk of injury. Be sure to gradually increase your exercise time and intensity for healthy weight management and cardiovascular fitness. If you have a chronic health condition, discuss your plans for exercise with a healthcare provider.
Summary
Sweating is an important way your body keeps you cool when you’re overheating from a fever, hot temperatures, or exercise. Although you might be burning calories when you sweat while exercising, weight loss of body fat and from burning calories comes from the exercise itself and not from the fact that you are sweating.
Sweating while working out is often a sign that you are exerting a good amount of physical effort. Other factors, including temperature and humidity, can also influence how much you sweat.
When you sweat—for any reason—it’s important to replenish the water lost by drinking water, juice, or electrolyte drinks.
