A seven time Danish dressage champion, Hartel contracted polio at age 23 while pregnant with her second child. Despite being paralyzed from the knees down, Hartel ignored the advice of her doctors and spent three years regaining the use of her limbs and re-learning the sport. In 1952, she became one of the first women to compete against men in Olympic equestrian events, winning a silver medal. Still suffering the effects of polio, Hartel was unable to mount and dismount on her own - gold medal winner Henri Saint Cyr carried her to the podium for the medal ceremony. After retiring, Hartel trained young Danish riders and founded Europe's first therapeutic riding center. In 1994, she became the first Scandinavian inducted into the International Women's Sports Hall of Fame.