New research finds that tattooed skin sweats differently than unadorned skin.
If you’re one of the many Australians and New Zealanders that have tattoos and are also part of the probably smaller crowd that reads the journal Medicine & Science in Sports & Exercise, you might have noticed a recent study conducted by researchers at Alma College in Michigan.
The study found that tattooed skin produces less, but saltier, sweat than unadorned skin. In theory, this could cause problems for inky runners, because a lower sweat rate could lead to a higher core temperature, and sweat with a higher sodium concentration could more easily lead to an electrolyte imbalance. Both occurrences hurt your performance in the heat. So, as a runner, are your tattoos cause for concern?
The executive summary: you probably shouldn’t sweat it. But there’s a caveat.
In the study, the researchers induced sweating to targeted areas of skin with a substance, pilocarpine, that’s usually used to test for cystic fibrosis. Sweating was induced in two spots: one where the subjects had a tattoo of at least 5.2 square centimetres, and the same untattooed area on the other side of the body (e.g., the same area of the right shoulder as where a subject had a tattoo on the left shoulder). On average, the sweat rate of tattooed skin was about half that of plain skin, and the sodium concentration of the sweat from tattooed skin was about 1.7 times greater than that of sweat from plain skin.
The critical question stemming from this finding, lead researcher Maurie Luetkemeier, Ph.D., told Runner’s World, is whether the same potentially harmful result would occur in reaction to the body producing heat, such as by running. Luetkemeier’s team will conduct research investigating that matter.
“I would think one would see similar impairments with exercise,” Ollie Jay, Ph.D., an expert in thermoregulation at the University of Sydney, told Runner’s World by email. “However, whether this would have an observable impact on whole-body evaporative heat loss is less certain. It would depend on the total surface area of tattooed skin (and therefore the skin area that secretes less sweat) and whether compensatory sweating would occur elsewhere.”
Robin Travers, M.D., a dermatologist and marathoner from Boston, said there’s another reason that altered sweating in part of the skin might not hurt your running. “There are many individuals with loss of sweating, known as anhidrosis, on small areas of the skin who are able to exercise safely to maximal capacity. This is because of compensatory sweating in normal skin.”
When asked to speculate, Travers said it would probably not be until at least half the skin was tattooed that running performance via altered sweating would suffer. So unless you’re in the tattoo body suit camp, you’re probably okay for now.
Still, it’s best not to be completely nonchalant about being a tattooed runner. Ciarán ó Lionáird, a heavily tattooed Irish Olympian with a 3:52 mile PB, times his tattooing for outside of his most important training and racing phases. “Getting tattooed takes a lot out of you, and the body needs to recover afterward,” he said.
As Luetkemeier notes, when tattoo ink is inserted under the skin, the body produces an inflammatory response that can at least temporarily damage the affected area. “I have not found a difference in sweating, other than in the first two to three weeks, when the wounds dry and skin flakes a little,” ó Lionáird said.