Before attending Johns Hopkins, John Lang went to the Baltimore Polytechnic Institute, where he excelled in many sports, including basketball, football, soccer, lacrosse and swimming. Due to the lack of other sports at Johns Hopkins, he concentrated on lacrosse, although he did still occasionally play football and basketball. Lang was selected for the All-Time Hopkins Team, and was a member of the team that played in the demonstration competition at the 1928 Amsterdam Olympics. After leaving Johns Hopkins, he continued to play lacrosse at the Mount Washington Lacrosse Club in Baltimore until 1935. He worked as an engineer for a metal manufacturer, and acted as president of the Maryland Association of Engineers. As an avid sailor, he became commodore of the Sailing Club of the Chesapeake.