As a consumer, Steven Pokk shares some rarefied company. Like basketball legends Shaquille O’Neill, Dee Brown and Allen Iverson, Pokk owns 15 pairs of Reebok sneakers.

But the Adidas AG-owned brand has fallen far since its heyday on NBA courts in the 1980s and 1990s. In a bid to rebound, it signed a 10-year deal in 2011 to be the official sportswear brand of CrossFit, then a budding workout regimen that mixes a range of fitness strategies, from weights and rowing machines to running and calisthenics. It was a savvy move for a company desperate to stay relevant.