Rhiannon Anderson has about 50 pairs of high heels in her closet. But she never wears them.
"We're kind of in the countryside," said Anderson, a stay-at-home mom in Alpharetta, Georgia. "If you wear high heels people will look at you weird."
Instead, Anderson, 39, spends most of her days in sneakers. And she's not the only one.
As American fashion has slowly become more casual, so has footwear. That trend has become especially apparent in women's sneaker sales, which have surged 37 percent throughout the U.S. in 2017. Meanwhile, sales of high heels have declined 11 percent during the same time period, according to the NPD Group's Retail Tracking Service.
Brands like Nike , Adidas , Dr. Scholl's, Roxy, Puma, Steve Madden and UGG, are just a few of the names that are getting the benefit of women slipping into more comfortable footwear. The trend is twofold: Consumers want comfort, and there are more options across all shoe categories.
"It's becoming kind of a basic consumer need to have comfort and the desire to be comfort because everybody's so busy and running around all the time," Beth Goldstein, NPD's executive director and industry analyst for fashion footwear and accessories, told CNBC.
"Brands that are focusing on comfort are doing better, because that something that women of all ages want," she said. The sneaker trend will likely continue in the double digits for the next few years, Goldstein added, as it becomes more of a lifestyle choice.
Conversely, sky-high heels — shoes with heels three inches or higher — are tumbling the fastest, Goldstein said, as consumers gravitate toward one pair of shoes that can be worn both day and night. Even for dressier occasions, more sensible heels are increasingly popular, the analyst said.
But it's not for a lack of choices in the shoe department. Retail inventory of high heels has risen 28 percent in 2017, compared with the year before, according to Edited, a market research firm.
"I don't think it's so much of a rejection in high heels as much as it is that there are many alternatives," said Gerald Storch, CEO of Storch Advisors, a retail advisory firm. He said women are actually buying more shoes — just across different categories.
"Women still wear high heels for for fancy events," Storch said, who has also served as vice chairman of Target . In fact, the boom in sensible shoes has become a way for consumers to express their personalities, he added.
"You can show masculinity, you can show femininity," he said. "You don't simply have to take a different color of a high heel shoe."
Meanwhile, athletic footwear grew 2 percent in the U.S. last year, generating nearly $20 billion in sales, according to NPD. Among women's leisure sneakers, Adidas and Nike drove almost half the growth in the segment.
Another contender competing for market share are designer sneakers. Rapper Kanye West and Stella McCartney both have collaborations with Adidas. Rap artist Kendrick Lamar has also teamed up with Nike. Rihanna's Puma line was so popular it sold out online.
For women like Liz Mitrani, 37, a dentist in New Jersey, the proliferation of sneakers provides both variety and comfort. Mitrani told CNBC she alternates between Prada sneakers and flats while at work, but stopped wearing heels "whenever possible."
"There are so many sneaker choices," Mitrani said. "You can customize them. It's a thing."
As for stay-at-home mother Anderson, she recently ordered a pair of Adidas NMDs online. But she said she's holding on to her heels, "just in case."