Reese Witherspoon, Cardi B, Yara Shahidi, Zendaya and even Hailey Bieber have already tried it out — but now the rest of the world can get their hands on Beyoncé's first Ivy Park athletic-wear collection under Adidas.The superstar founded Ivy Park in 2016 but when she becamecreative design partner of Adidas in April 2019, she decided to relaunch her label under its umbrella.