Girls sweat differently as they age — moving from "understudied" to "understood" could help them stay safe and active in sports amid rising temperatures

You're a teenager. You're facing social pressures, your body is changing, and you're practicing hard to make the basketball team this year. Or the soccer team. Maybe track. 

You live in India. Or France. Could be California. And you've got to manage your training around air quality advisories and dangerous heat waves so you can stay safe while you exercise.

There's also this: You're a teen girl, and it turns out no one fully understands how your sweat responses are changing as you go through puberty or how to help your evolving body feel more comfortable and confident during periods of exertion and high temperatures. 

"Historically, females have been underrepresented in thermoregulation research, meaning there are still important knowledge gaps to address," Hannah Blount told CG. 

Blount, a postdoctoral research fellow in thermal physiology at the University of Southampton in the U.K., wanted to address some of those gaps. She recently led a study looking at thermoregulation — the biological process that enables a body to maintain an internal core temperature — in 28 female participants aged 8 to 25 to show how and when perspiration changes throughout development.

"As girls progress through puberty, the way their bodies regulate temperature changes," Blount said. 

"Understanding these developmental changes is important because it helps ensure that guidance, exercise recommendations, and clothing designs are appropriately tailored to adolescent girls rather than assuming they respond like either younger children or adult women."

And, indeed, adolescents don't seem to respond in exactly those same ways. Blount's study, published in April in the journal Experimental Physiology, found that while younger children sweat mostly from their hands and feet, teen girls experience an increase in perspiration across their torsos. 

The study — which, according to a university release, involved participants riding exercise bikes for 40 minutes in a room set to nearly 97 degrees Fahrenheit (36 degrees Celsius) — identified age 14 as the turning point. It's the age at which youth assigned female at birth begin to sweat increasingly from their chests, abdomens, and backs.

It also happens to be the age at which gender equity advocates have observed a noticeable uptick in girls quitting sports.

"By age 14, girls drop out of sports at twice the rate of boys, due to social expectations, lack of investment in quality programs, and other factors," Jayathma Wickramanayake, Policy Advisor on Sports Partnerships at U.N. Women, told CG.

There are indeed a range of social and economic dimensions to consider when it comes to unpacking teen girls' sports attrition. But Wickramanayake told CG that there is no reason to doubt that the physical and mental features of puberty can play a role.

"There is plenty of evidence that as girls enter adolescence, new pressures emerge related to body-image insecurities, social comparisons, confidence dips, fear of judgment, and the stigma and logistical barriers around periods," she said.

Researchers have also previously identified perspiration as well as breast and chest development among the discomforts that may contribute to teens stepping away from the activities they've loved. But they could lose out on even more than the game.

"Participation [in sports] can improve cardiovascular health, support healthy development, enhance confidence and well-being, and foster social connections," said Blount, herself a former international-level track cyclist. "Supporting participation helps create opportunities for lifelong healthy habits and enables girls to enjoy the many benefits that sport can offer."

Involvement in extracurricular activities such as sports may also enhance educational engagement, build leadership skills, and pave a path to career success. According to U.N. Women, "80% of female Fortune 500 CEOs played sports growing up, and most say sport helped them succeed." 

Equitable access to all of these benefits is a key reason advocates for transgender kids have fought for their inclusion in sports. Meanwhile, in addition to discriminatory policies and social exclusion, body changes in puberty, self-image, and binders made uncomfortable in hot weather may impact trans kids' sports participation too. Further research into how thermoregulation may change for trans and nonbinary teens as they grow and temperatures rise could also help to strengthen youth participation in sports.

In the meantime, U.N. Women maintains that fairly small actions — like improving access to a range of menstrual product options and functional sports gear — can make a big difference in fostering belonging in athletics. 

Researcher Blount seems to agree.

"Feeling comfortable and confident while being active is an important factor in participation, so small improvements in support and design may help reduce barriers that discourage girls from remaining involved in sport," she said.

Her study — which received support from the Engineering and Physical Sciences Research Council and Nike, Inc. — could help inform sportswear design "that better reflects the thermoregulatory needs of teenage girls," Blount noted. 

The researcher also said that her team's results could help shape public health messaging "around hydration, heat management, and safe participation in physical activity, particularly during warm weather."

Such measures are set to become even more critical amid anthropogenic climate change and the volatile, intensifying weather events it can fuel.

"As global temperatures rise, understanding how adolescents regulate body temperature during physical activity becomes increasingly important," Blount told CG. "Higher environmental temperatures place greater demands on the body's cooling mechanisms, including sweating." 

Blount called for further research at the intersection of thermoregulation and extreme heat. More studies like hers may help to build a future where kids of all ages and gender identities can safely, comfortably, and confidently move and play — and maybe even sweat without shame too.

Kirsten Krueger contributed to the editing of this article.