Mara was an amateur through and through, though he did have chances to turn pro. He turned down a contract offer from the Detroit Red Wings and instead headed to Halifax to serve as a lieutenant in the Navy during World War II. He later had chances to join the New York Rangers and Toronto Maple Leafs but never did.
It turned out to be a blessing as Mara retained his amateur status, allowing him to compete in the Olympics.
The Olympics clearly had a big impact on Mara's life. Later in life he helped to create and chair the Olympic Trust of Canada (nowadays known as the fundraising arm of the Canadian Olympic Committee), which raised millions of dollars to help fund amateur Olympic athletes. Mara's efforts earned him the Order of Canada in 1976 and saw him inducted into the Canadian Sports Hall of Fame in 1993.
Mara had run his father's liquor distributing business until divesting in 1970. He also served as a director of Maple Leaf Gardens.