He enrolled at Harvard University in 1911 at age 18. While attending Harvard, Hardwick was a varsity athlete in three sports. He was captain of Harvard's baseball team, a shot putter, and the "strong man" of Harvard for two consecutive years. He gained his greatest fame, however, playing for Percy Haughton's Harvard football teams from 1912 to 1914. During Hardwick's three years as a starter for Harvard, the football team did not lose a single game compiling records of 9–0 in 1912, 9–0 in 1913, and 7–0–2 in 1914.