These days, it’s rare to watch a game on TV—the sport doesn't matter—without seeing a player who’s inked up, most commonly with one or two “sleeves,” the common term for completely covering one’s arm in ink.
For pro athletes, tattoos are not uncommon. But until recently, no one had seriously considered whether inserting ink into the dermal layer of the skin—the same layer where sweat glands live—could affect a person's ability to sweat.
Now, there's some evidence they might.
In a small new study from Alma College in Alma, MI, researchers tested 10 healthy men with upper-body tattoos on one side of their body, and an equal amount of bare skin on the other side of their body (e.g., if they had a right shoulder tattoo, their left shoulder was not inked).
After inducing sweat with a chemical most commonly used to test for cystic fibrosis, researchers collected sweat on both sides of the body (sounds fun). The results: The researchers found that they collected half as much sweat from the tattooed area. Furthermore, the sweat from the tattoo contained twice as much sodium as the untinted skin; it was much saltier, in other words.
Does this mean that the ink inserted into the skin when you get a tattoo damages sweat glands? It’s a possibility. But it’s unlikely that tattoos—even a Chris Andersen-quality covering the entire body—would knock out enough sweat glands to lead to overheating, says the study lead, Maurie Luetkemeier, a professor of integrative physiology and health science.
That's good news for athletes everywhere, and good news if you’re thinking of going under the needle soon. Just be mindful that the area may not sweat normally. On the plus side, if you sweat a lot in certain places on your body, maybe you should just consider covering that area with a tattoo.