Dr. Alexis Colvin continued exercising during her own three pregnancies .
Dr. Alexis Colvin is an orthopedic surgeon specializing in sports medicine at the Icahn School of Medicine at New York 's Mount Sinai Hospital .
Dr. Alexis Colvin , an orthopedic surgeon specializing in sports medicine at the Icahn School of Medicine at New York 's Mount Sinai Hospital , continued exercising during her own three pregnancies .