After years at the East Bank Club teaching packed fitness classes geared to moms, Adina Rosenberg opened this Lake View gym in April. Classes include pre- and postnatal Zumba, Postpartum Core, Mommy and Me Baby Bootcamp, and Baby Bjorn Aerobics, plus CPR, infant massage, and myriad parent-focused workshops. More proof that the business is nailing its mission? The gym offers onsite babysitting for children as young as six weeks old.