Kevin Plank, 47, founder of popular athleticwear brand Under Armour, announced Tuesday that he would be stepping down as CEO. He will be replaced by Chief Operating Officer Patrick Frisk, effective Jan. 1. Frisk will also join Under Armour’s board. Plank will now serve as executive chairman of the board and brand chief.

Kevin Plank announced this week that he’s stepping down as CEO of Under Armour.

“Patrik is the right person to serve as Under Armour’s next CEO,” Plank said in a statement. “As my partner during the most transformative chapter in our history, he has been exceptional in his ability to translate our brand’s vision into world-class execution by focusing on our long-term strategy and re-engineering our ecosystem through a strategic operational and cultural transformation.”

Frisk joined Under Armour in July 2017. Prior to that, he had a brief stint as a director at Gildan Activewear (asi/56842). He has decades of experience in the apparel industry, including serving as CEO of footwear company Aldo and coalition president of Outdoor Americas with the VF Corp.

Plank founded Baltimore-based Under Armour in 1996, while he was still in college. The company currently has a market value of about $9.1 billion, though sales increases have slowed after years of rapid growth. Under Armour forecasts a “slight decline” in North American sales for 2019.

Under Armour offers clothing in the promo market primarily through an exclusive partnership with alphabroder (asi/34063). Plank appeared on Counselor’s Power 50 list for two years, ranking 13th in 2016 and 31st in 2017.