As you might have noticed, we’re big on hydration here at Nuun. And as you might have noticed, hydration and sweating often go hand in hand. Here are some quick facts about perspiration to peruse while you wait for your favorite Nuun tablet to dissolve.
1. Humans are the best sweaters.
Every animal has a way to dissipate heat—dogs pant, moths move blood from their heart to their abdomen, elephants stay cool thanks to their hair. Humans and a few other species, most notably horses, use sweating as their main way to stay cool.
Sweating is so integral to being human that some have posited a key role for it in evolution. Our ability to stay cool via sweating, some say, allowed early humans to track prey for hours, eventually causing the prey to collapse because of heat exhaustion. In this view, sweating allowed early humans to get high-quality calories and allowed running skill to be a desirable evolutionary trait.
2. There are two types of sweat glands.
Humans have apocrine glands and eccrine glands. Apocrine glands are the type that most other animals—who do sweat, but not as their main way of heat dissipation—have. In humans, apocrine glands are found only in certain body parts, including the armpits, nipples, eyelids and nostrils. The sweat produced by apocrine glands is oily and becomes smelly as it decomposes. It’s sensitive to adrenaline, which is why your palms, armpits and parts of your face might start sweating when you’re emotionally stressed.
Eccrine glands are found on your skin throughout your body. They’re the ones that release sweat to keep you cool, although, like apocrine glands, they can be triggered by emotional stress.
3. The fitter you are, the more you sweat.
As your aerobic fitness improves, you start to sweat earlier and at greater volume when exercising. This adaptation allows you to sustain a higher work load for a longer period of time, because it keeps your muscles cool enough to continue to function at a given intensity (up to a certain point of dehydration, of course).
But wait: Why does it seem like unfit people sweat more? The answer has to do with what constitutes a workout level of exertion for different people. If you’re fit, exercising at, say, 75% of your maximum heart rate involves moving pretty quickly. But for sedentary people, it’s easy to reach that level of exertion through something like climbing a few flights of stairs, and they might start sweating profusely. But if fit you and your unfit neighbor are both exercising at the same intensity, you’ll sweat more, because you’re moving faster, and are therefore generating more heat.
4. Sweat rates and composition vary greatly among people.
If you take a group of athletes of similar fitness and have them do a workout together, it’s likely that afterward some will be drenched, some sort of sweaty and some perhaps glistening a little. Some people are genetically more prolific sweaters than others (and therefore often more in need to be mindful of their hydration status).
The composition of your sweat might also be a lot different from that of your training partners. While everyone’s sweat becomes less dense with sodium, potassium and other electrolytes with continued exposure to heat, that acclimatization occurs within a genetically set range. There’s at least one facility in the U.S. that analyzes athletes’ sweat composition and recommends hydration strategies based on the findings.
5. Many cultures have a group-sweating tradition.
From Finnish saunas to Turkish baths to Native American sweat lodges, humans have long valued getting together to perspire. Anthropologists have theorized that group sweats build social bonds, reduce conflict and help to mediate disagreements.
We couldn’t agree more. Consider your next workout with friends a portable sauna.