When she was 6-years-old Truus Dam began doing gymnastics exercises in her home in Enschede. Dam soon participated in many competitions, becoming the Dutch youth champion and a two-time champion in the Dutch region of Twente. In 1952 she was named as a reserve on the national team for the Helsinki Olympics but did not compete at the Games. Four years later she won bronze at the Dutch championships in the women’s all-round competition. Following her active career Dam became an international gymnastics jury member and an honorary member of her local club.