In a new commercial for Apple Music, Taylor Swift takes on a treadmill ​and loses. It's an interesting endorsement, since Swift and Apple have a complicated past. Swift famously wrote an open letter to Apple shaming them for not paying artists royalties during customers' free 90-day trial of Apple Music. They listened, and changed their policy. As a result of the change, Swift chose to stream her album 1989 exclusively on Apple Music. And now she happens to be their spokesperson, along with (probably) a stunt double:

Sources: Twitter: Taylor Swift | YouTube: Beats 1 Radio