New studies show that heat can cause similar skin damage as UV rays, but that hot and sweaty environments might not be significant enough to worry about.
Recent reports that sweaty workouts can cause skin damage and age spots had some workout fanatics wondering if they should cancel their hot yoga and spin classes.
The articles in Allure and Well+Good connected trendy workouts in heated environments to increased skin redness and signs of aging such as wrinkles and age spots.
“Spin instructors and women who were taking hot yoga upwards of five times a week were getting more discoloration and persistent redness than other patients,” Dr. Doris Day, a clinical associate professor of dermatology at New York University (NYU) Langone Medical Center, told Allure.
While Day and other dermatologists with a fitness fanatic population of clients may notice this effect in their clinical practices, it hasn’t been confirmed yet by any research that working out in a hot environment can cause changes to the skin.
Some dermatologists want to see more research before they start to warn their clients about sweltering workouts.
Previously, researchers and consumers were focused on the visible aging effects of ultraviolet (UV) radiation.
While it’s beneficial to protect yourself from the sun’s UV rays with daily sunscreen, “it’s not just UV light that causes these symptoms” like wrinkles and age spots, Dr. Nada Elbuluk, assistant professor of dermatology at NYU Langone Medical Center and an expert in hyperpigmentation, told Healthline.
Scientists have done a lot of research around the effects of UV light, but Elbuluk says dermatologists need more data on how heat affects people’s skin.
The impacts of visible light and artificial light also warrant more study.
“We found that heat can cause, over time, similar changes that UV does,” she confirmed.
But heat studies generally look at the effects of direct contact of heated things on the skin.
So the research might not be applicable to the potential impacts of hot yoga on skin.
Changes to the skin resulting from heat are essentially a type of injury.
Heat can increase inflammation in the skin, which can lead to breakdown of collagen.
Collagen keeps your skin firm and elastic.
That means heat can cause more fine lines and wrinkles — “things we classically associated with aging and non-exposure,” Elbuluk pointed out.
A few studies — not a lot, Elbuluk noted — specifically look at how heat relates to melanin.
Anything that leads to inflammation to a melanocyte, or pigment-producing cell, can cause injury and more pigmentation.
Dark brown spots, or age spots, can start to appear, or a spot you already had can get darker.
People with darker colored skin, which has more melanin production, are more prone to this damage.
The studies also show heat can prompt an increase in angiogenesis, or the formation of new blood vessels, and blood vessel growth. That makes veins more visible.
For people around hot machines, for example, prolonged exposure to heat can injure the skin, which results in a breakdown of collagen and elastin.
This can also be due to a condition called erythema ab igne, which dermatologists have known about for decades.
Erythema ab igne is a skin condition caused by sustained and repeated heat exposure to skin, Elbuluk explained. Initially, the skin turns red, then it turns brown.
Heating pads were the main culprit in the past, but now there are an increasing number of cases of this condition occurring on people’s thighs because of laptops.
The reason the heating pad or hot laptop turns the skin brown goes back to inflammation.
If your skin stays red for a long enough time, it shows that there’s increased inflammation — so it affects the melanocyte, which produces more brown color.
“When there’s prolonged heat, we see damage,” Elbuluk said.
She stressed that the exposure has to be lengthy, so she’s doubtful that hot yoga five times a week will really damage your skin.
There are professionals who need to worry about heat and aging.
However, fitness instructors or hot yoga or cycling aficionados, as far as we know, aren’t among them, according to current research.
Exercise in heat isn’t prolonged enough to cause damage, based on the science that’s currently available.
“We don’t know of any effects on human skin with excessive heat exposure and exercise,” Dr. Kord Honda, a dermatologist at University Hospitals Cleveland Medical Center, told Healthline.
A study done in South Korea stated that “it has been reported that chronic IR (heat) exposure can cause pronounced elastosis in mouse skin, changes that mimic the damage caused by UV.”
However, Honda pointed out the paper was a study of mice exposed to significantly high temperatures.
“We don’t know the effects of extreme heat in humans,” he affirmed.
Heat is also often studied at the same time as UV, visible light, or artificial light.
“Currently, we don’t have enough data to say the other types of light aren’t contributing,” Elbuluk concluded.
Elbuluk told Healthline that she’s not seeing any damage or rapid ageing in her patients who frequent hot yoga or spin classes.
But she said that professions that are exposed to high temperatures for a prolonged time, such as bakers, chefs, and glassblowers, might see changes.
If you’re in a profession where you’ll constantly be exposed to high heat, make sure your skin is covered and protected.
Cool down your skin as quickly as possible after a dose of extreme heat to prevent inflammation.
In terms of spin class or hot yoga, the main things to be worried about are dehydration and folliculitis.
Increased sweating combined with tight clothing can cause hair follicles to become inflamed and lead to acne.
So go forth to your spin class, drink a lot of water, and wear breathable fabric.
You won’t look any older because of it.