Yoga-pants retailer Lululemon Athletica Inc. agreed to buy Mirror, a maker of in-home fitness equipment, for US$500 million, broadening a partnership that began last year as exercise increasingly moves away from traditional gyms.

Mirror will operate as a standalone company within Lululemon and retain its chief executive following completion of the deal, the companies said Monday in a statement. The purchase will be paid from Lululemon’s primary sources of liquidity, including US$800 million in cash and US$700 million in credit facilities.

Once a more traditional retailer, Lululemon has been pushing increasingly into fitness as experiences sell. Although Lululemon has always leaned into health -- with many of its existing stores offering free running clubs or yoga classes -- last summer it moved to monetize its workout offerings by opening a Chicago store with a gym.

Mirror offers customers live classes and on-demand workouts, mimicking what they might have once paid a personal trainer at the gym to oversee. Lululemon took a minority stake in Mirror last year.

Lululemon shares rose as much as 4.1 per cent in after-market trading. Shares of rival home-fitness company Peloton Interactive Inc. fell as much as 4.6 per cent.

The deal is expected to close in the second quarter of the fiscal year.