Long before boutique fitness classes and wellness influencers came into existence, there was Kate Hudson and her Pilates reformer. The actress-slash-Fabletics founder is an unofficial spokesman for her favorite workout. As she told SELF last year, "Nothing, literally nothing, makes me feel like I'm back to my body more than Pilates. I'll travel, and I'll go for a run or I'll Spin. But when I go home and get on the reformer or the Cadillac, my body immediately goes back. I can see an instant shift."