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Sarah Schopp had no qualms about buying her daughter a sports bra. And even though her 5-year-old won’t technically need one for several more years, it’s not hard to find one for her — stores such as Target, Justice, Ivivva and Athleta Girl are selling them in tiny sizes, and they are flying off the shelves.

Sports bras are big business. The NPD Group Consumer Tracking Service reported in 2015 that sports bras now make up 20 percent of the $6.3 billion dollars spent on bras in the United States. The group’s data indicates the athleisure trend has exploded since 2013, with more women, particularly millennials, choosing sports bras as their everyday undergarment.

Now companies are expanding their inventory to appeal to younger girls, and while some parents balk at the thought of sending their daughter off to first grade wearing a sports bra, many are okay with the trend.

“I bought my daughter a sports bra from Target,” says Schopp, from Toronto. “I don’t like the idea of kids wearing a sports bra with shorts to gymnastics, and I don’t think it’s necessary to show that much skin, but she wanted hers for off-the-shoulder tops, and because her friend’s older sister wears one. I thought it was okay for that purpose.”

Parents say sports bras designed for preteens are not meant for support; rather, they are more comfortable than undershirts in the summer. When girls have to change their shirt at camp, in gym class or on the sports field, a sports bra is practical, rather than sexy. Colorful sports bras with strappy backs are especially popular, and girls are wearing them under sheer, thin or loosefitting tops with large arm holes.

Educational psychologist Michele Borba, however, said the trend has gone too far. The author of “UnSelfie: Why Empathetic Kids Succeed in Our All-About-Me World” has been working with children, educators and parents for more than 30 years. Ten years ago, she warned media audiences that 9 was the new 13. Now, with the popularity of sports bras, social media and even makeup for girls, Borba is seeing that trend spiral further downward.

“Now, 6 is the new 9,” she said in an interview. “Everything is getting filtered down with things like colored lip gloss, sexy bathing suit ads tailored for girls, skimpier Halloween costumes, iPads for infants and looser movie ratings. Childhood is something every kid deserves. Parents might not see the big picture, but it’s something you can’t regain and you can’t rewind. Kids are being pushed to grow up so soon.”

While there are many practical reasons to buy a young girl a sports bra, Borba wants parents to keep some things in mind while shopping.

“There’s nothing more wonderful than active kids, but what you wear doesn’t determine that,” she said. “You don’t have to wear certain clothes or buy certain brands to develop a healthy lifestyle.”

From a medical perspective, there is no research that suggests that wearing a sports bra at a young age is dangerous. In fact, some girls may need a bra earlier than most parents might realize.

“Between 10 and 25 percent of healthy 7- and 8-year-old girls develop breast buds,” said Cassandra Kelleher, a pediatric surgeon at Massachusetts General Hospital in Boston.

She also points out that heavier girls, African Americans and Hispanic girls tend to develop earlier than Caucasian and Asian girls, making chronological age an inappropriate indicator of when a girl should start wearing a bra.

“Girls can feel uncomfortable when their breast buds show through clothes, or experience chafing or abrasion when their breast buds rub on clothing during exercise,” Kelleher said. She and her colleagues worry about the effect on girls who focus on their body or their appearance at such a young age. For those who develop early, an extra layer of fabric may be a good way to alleviate their concerns.

Makers of athletic wear for girls say they are putting out a positive message, regardless of when girls actually need a bra. With 67 stores and showrooms in the United States, Ivivva, Lululemon’s brand for girls, has been carrying sports bras since stores opened in 2009. What began with two styles has now expanded to five or six options for girls from sizes 6 to 14.

“Our products serve the function our guests are looking for in life and when they are doing activities. Sports bras are part of that,” said Natalie Martz, design director at Ivivva. “It’s not about being sexy or looking like their mom. It’s about looking age-appropriate and giving girls the coverage they need to be active, focus on their goals and kick that soccer ball as hard as they can.”

Schopp made sure her daughter knew her sports bra came with rules.

“I told her she could not wear it just with shorts or on its own to gymnastics,” she said. “I made it seem like more of a fashion item, rather then something that is actually used for when you have breasts. She understood and agreed.”

Erin Silver is a writer and blogger based in Toronto. Visit her at erinsilver.ca.

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