The Science of Sweat: Five Health Benefits of Sweating

Sweating is the body’s natural cooling system ‒ and although it’s sometimes stinky and always a little messy, it’s integral to keeping us functioning normally. When your body temperature rises from exercise, stress, hormonal changes, or rising external temperatures, perspiring helps keep your internal temperature at a comfortable 98.6°F (37°C).

What Is Sweat?

The body is home to two kinds of sweat glands: eccrine and apocrine. Eccrine glands are found all over the body. As your internal temperature rises, the nervous system stimulates the eccrine glands to release sweat, cooling everything down. Apocrine glands are found primarily in the underarms, hairline, and groin. These glands are responsible for producing the bacteria that cause body odor and those dreaded yellow stains.

Perspiration is regulated by the sympathetic nervous system, which sends signals to the sweat glands when it’s time to release fluids. Humans have anywhere from 2 million to 4 million sweat glands, with the highest density found on the palms of the hands and soles of the feet.

Sweat is mostly water but also contains sodium (which is why it tastes salty), chloride, potassium, calcium, and magnesium. And just like with fingerprints, everyone has a unique combination of these minerals making up their own unique sweat.

Issues related to sweating

Although how much the body sweats varies from person to person, there’s a threshold ‒ anywhere from three liters to upwards of 10 to 12 liters ‒ that’s considered normal, and this depends on a wide variety of factors, such as age, sex, physical health, and exercise level. For example, a woman going through menopause or perimenopause may experience an uptick in how much they sweat, particularly at night and during “hot flashes.”

Normal levels of sweat aside, there are some issues related to sweating too much or too little. Hyperhidrosis (or excessive sweating) can be embarrassing and may increase the risk of dehydration. Most cases of hyperhidrosis are localized to the underarms but also commonly affect the back, hands, and face.

Hypohidrosis, or anhidrosis, is when you sweat too little. It mainly occurs as a result of skin injuries like burns, radiation from cancer treatment, and the use of medications that affect the skin, nerves, and endocrine system. This condition can easily lead to heatstroke, as the body has lost its main way to regulate internal temperature. If you think you have hyperhidrosis or anhidrosis, consult your primary care physician.

Four Health Benefits of Sweating

1. Acts as natural detox

The kidneys and liver do most of the heavy lifting when it comes to detoxing the body, but sweating acts as a natural detox pathway, too. Heavy metals like arsenic, lead, and mercury as well as chemicals like BPA from plastic can be expelled from the body via the sweat glands. One study from 2016 found that people who exercised regularly (and, consequently, sweat more) had lower levels of heavy metals in their blood. Another study found that sweating “appears to be a clinically useful tool to facilitate the release of BPA through the skin in order to eliminate this toxicant from the human body.”

2. Can improve heart health

Sitting in a dry sauna ‒ which can range in temperature from 150°F to 195°F (66°C to 91°C) ‒ can make you lose up to half a liter of sweat per session. A 20-year study found that Finnish men who visited the sauna four times per week had significantly lower rates of heart disease and were less likely to die of cardiovascular-related causes.

3. May increase weight loss

Sweating is thought to boost weight-loss efforts. Water weight lost during a heavy workout will lower the number on the scale but isn’t permanent weight loss; intense exercise makes your body work harder to regulate your temperature, which uses energy and burns calories. But just because you aren’t sweating buckets during your workout doesn’t mean it wasn’t effective – some people simply sweat less than others.

4. Delivers glowing skin

When we sweat, our pores open and allow for the opportunity to get rid of all the dirt, oil, bacteria, makeup, and debris in them. Sweating’s also thought to improve the tone, clarity, and texture of skin. However, after a heavy sweat session, be sure to shower and wash your face to avoid having bacteria settle back into your pores.

Don’t Sweat It

Though some evidence suggests that more sweat equals a better workout – and that people in better shape sweat more than others – there’s a ton of variation from person to person. Sweating is a natural human process, like breathing and sleeping. Sweating helps flush out toxins, gives your skin a healthy glow, and can even supercharge your weight-loss efforts.