Fitness Rarely does Rachel Pustilnik get through an exercise class without someone crying. But that’s OK. This is Stroller Strides. A little crying is to be expected. The tots come along on this exercise hour. They watch from the comfort of their strollers as the moms work up a sweat. “Of course you get criers,“ said Pustilnik, owner of the local Stroller Strides franchise. “That’s part of motherhood.“