Why would anyone spend $50 for a tank top that they plan to sweat profusely in, especially in this economy? Well, it doesn't look like they are.

Lululemon Athletica

(LULU) - Get Report

, maker of yoga-inspired workout apparel, posted a 24% decline in first-quarter earnings, as sales at the company's stores opened at least a year weakened.

The news sent shares tumbling more than 12% to close at $13.34.

The company earned $6.5 million during the quarter, or 9 cents a share, compared with $8.5 million, or 12 cents, in the year-ago period. Analysts expected earnings of 8 cents.

Sales jumped 6% to $81.7 million from $77 million, but same-store sales declined 8%.

Noticing shoppers reluctance to purchase higher-end merchandise, the company lowered its price point on its best-selling yoga mat to $28 from $54, Richard Jaffe, analyst at Stifel Nicolaus wrote in a note on Thursday.

This move increased sales of mats and accessories by 40%. But since most of its workout apparel is made from organic and natural fibers, the company cannot lower prices until cheaper ways to produce these items are discovers.

Looking forward, Lululemon predicts second-quarter earnings in the range of 8 cents to 9 cents a share.

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