Maggie Lettvin
 Margaret B. Lettvin is an American writer and promoter of exercise and health. She was known in the Boston area in the 1970s for a television show called Maggie and The Beautiful Machine and a book based on the show. After a serious car accident she developed a set of exercises for back pain which became Maggie's Back Book (ISBN 0395251478).She is the widow of MIT professor Jerry Lettvin.