Stretch. A lot. Amy stresses the importance of having a limber body and says that becoming more flexible has helped Selena "let go." Sometimes, Selena will even do a combined stretching and vocal warmup session.

She and Amy go on long hikes with some of Selena's crew, where they'll break to do circuit training and "arm dancing" and "side chassés up a hill." Amy said, "I've always believed the best way to keep your muscles active is to mix it up. We switch things up almost every day."

She and Amy go on long hikes with some of Selena's crew, where they'll break to do circuit training and "arm dancing" and "side chassés up a hill." Amy said, "I've always believed the best way to keep your muscles active is to mix it up. We switch things up almost every day."

She and Amy go on long hikes with some of Selena's crew, where they'll break to do circuit training and "arm dancing" and "side chassés up a hill." Amy said, "I've always believed the best way to keep your muscles active is to mix it up. We switch things up almost every day."

Selena has been a Pilates superfan for forever. Selena has been working with trainer Amy Rosoff Davis for years now; they train three to five days a week regularly and up to seven days a week if she's going on or currently on tour.