Footwear sales in the U.S. are forecasted to increase through 2021 on account of strong growth in the sport leisure category, according to The Future of Footwear, a new report from The NPD Group forecasting growth and declines across key categories.

Furthermore, sport leisure—which is dominated by athletic-inspired casual sneakers, and also includes sport slides and skate shoes—is expected to surpass fashion as the largest footwear category in 2020.

Shifting fashion attitudes towards athleisure have benefited the leisure footwear space, at the expense of the fashion and performance segments. According to NPD’s Retail Tracking Service, in the 12 months ending August 2019, sport leisure footwear grew 7 percent, while fashion declined 5 percent and performance footwear sales were down 7 percent.

“I expect that in the upcoming years, more brands will effectively respond to the shift away from performance and fashion footwear to focus on what has become the new norm: athleisure footwear,” said Matt Powell, senior industry advisor, Sports, The NPD Group. “The nature of fitness in the U.S. has changed, and this has been a major contributor to footwear market shifts. Consumers are committed to a healthy lifestyle, but that commitment is lighthearted. They no longer define themselves by their sports activities. As a result, consumers are looking for shoes that are less technical and instead more versatile and every day.”

Sport leisure’s growth is poised to be driven by running- and basketball-inspired styles, which are shoes with a performance-based heritage that are intended for style as opposed to sports activities. The men’s market is expected to lead the sales growth in sport leisure, with heavy contribution from kids as well.

Fashion is forecast to decline through 2020, but rebound slightly in 2021 on account of growth in comfort-oriented silhouettes such as fashion slides, slippers, and drivers/loafers. On the other hand, sport-inspired trends will have a negative impact on the thong, flip-flop, and ballerina segments.

“As consumers continue to prioritize athleisure and deprioritize dress, comfort and function will be as important as aesthetics in leading the fashion category back on the plus side,” said Beth Goldstein, executive director, fashion footwear and accessories analyst, The NPD Group. “While sport leisure will continue to grow at fashion’s expense, consumers will seek options outside of sneakers. As a result, active-inspired fashion silhouettes, particularly those with lower and thicker heel options and added comfort features, will help the category in the years ahead.”