KANSAS CITY, Mo. — “We’re very self-conscious about our bodies, and we’re fighting that every day.” So said Misa Kuranaga, a principal dancer with the San Francisco Ballet, one day in December by phone.

She was in the midst of rehearsing the role of the Sugar Plum Fairy for the annual “Nutcracker” production and ruminating on the importance of leotards. As she spoke, Ms. Kuranaga was wearing a leotard with a mesh top and mock turtleneck, and a patterned body that began just at the breastbone.

“What you wear doesn’t make you a better dancer, but it can make you a more confident dancer,” said Sarah Chun, a first soloist with Northern Ballet in Leeds, England, via Skype a few days later. “If you’re not having the best morning, but you’re wearing something that you like, and you look at yourself in the mirror you think, ‘Oh yeah, I’ve got this.’”

When it comes to workout wear, leggings and tank tops tend to get all the attention, but leotards, once a favorite of the aerobics crew and the essential everyday wardrobe of the professional dancer, could be making a comeback thanks to the popularity of ballet classes as exercise regimens.