[G]irls, in all your gettings get health, it is the foundation of success in every undertaking.
The invention of modern girls in the early 1900s was built on fit, healthy bodies. While competitive sports were often reserved for boys, girls were encouraged to wear looser clothes and engage in exercise that prioritized fitting in.
Jump rope songs often reinforced what girls could be, depending on the lyrics.
See Girlhood in 3D! Explore a model of the gym suit.