The United States National Library of Medicine defines '''exercise science''' as "the scientific study of human movement performed to maintain or improve physical fitness."<ref>http://www.nlm.nih.gov/tsd/acquisitions/cdm/subjects34.html</ref> | The United States National Library of Medicine defines '''exercise science''' as "the scientific study of human movement performed to maintain or improve physical fitness."<ref>http://www.nlm.nih.gov/tsd/acquisitions/cdm/subjects34.html</ref> |