The decade long athleisure apparel trend could be finally dying out, which wouldn't be sexy news for its pioneer Lululemon (LULU) - Get Report .

Analysts at Canaccord think the jig is up for the trendy Lululemon, according to a recent note, in which they speculate that the brand's customers aren't coming back in the same numbers.

"We believe Lululemon's focus on yoga bottoms (pants and crops) has been a tremendous asset to comparable store sales growth, but little innovation and only modest design updates to its assortment run the risk of the category becoming a liability," wrote the analysts, who called the stock a sell.

Canaccord recently surveyed women who bought Lululemon pants in the last year to determine their plans for the next 12 months.

Here's what they found, none of which bodes well for the brand.

The women said they'd buy about 18% fewer pants from Lululemon.

Only half the consumers who bought the company's pants last year plan to do it again this year.

Lululemon's products represent 53% of women's total athletic pant assortment, likely setting a ceiling for future share gain potential.

Half the respondents wear its pants for fashion versus function.

"We believe 2016 was as good as it gets for Lululemon," wrote Canaccord. "Our sell rating is based on the stock's negatively skewed risk/reward characteristics exacerbated by a P/E multiple of 27 times our estimates that we believe is too high for a company with prospects for decelerating sales trends."

The analysts wrote that the latest tastes in fashion call for an "inverted triangle," the very opposite of Lululemon's signature body-hugging tops and bottoms. "The new trends in denim suggest that triangle is turning right-side up (tight tops paired with roomy bottoms)," they wrote, a fashion shift they saw at the MAGIC/Platform trade show in August.

"By our math, an 18% reduction in pairs of pants purchased could amount to a 5% hit to annual comparable store sales," they wrote. "As such, we expect to see comparable store sales decelerate in the second half of 2017 and into 2018, and are lowering our comparable store sales/earnings per share estimates to reflect this. Our 2017 earnings per share estimate goes to $2.43 from $2.48 and our 2018 earnings per share estimate to $2.47 from $2.57. Our price target goes to $45 from $47, implying 32% downside."

In spite of Canaccord's note, Lululemon can look back on solid news: it had an up holiday season, unlike many other retailers, and raised its sales guidance for the fourth quarter from between $765 million and $785 million, to between $775 million and $785 million.

According to an earlier interview with Lululemon CEO Laurence Potdevin for TheStreet, the company is expanding its men's and children's lines, and continuing to develop new fabrics that cater to athletes. Lululemon anticipates doubling sales of its women's and men's businesses within three years to about $3 billion and $1 billion, respectively. Meanwhile, it recently opened a men's store in Soho in New York City, and has promoted an executive to be general manager of its children's line, Ivivva.

For this article, however, Lululemon did not respond to a request for comment.

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