On a Tuesday in September, Mary Ruble walked up to the barre of the Westside School of Ballet in Santa Monica for a 7:45 a.m. ballet class, joining about 30 women of all different ages. They ...

Fans flocked to it not only for its promise of lean muscles and improved strength, but there was also an undeniably pleasing aesthetic to barre. It taps into the graceful world of ballet with its ...