In 1921 Dutch won an AAU title as a player with the Kansas City Athletic Club Blue Diamonds. In 1925 he coached Washburn College to an AAU title, the last time a college team won that championship. Later he coached at Northwestern, getting 237 wins during his time there, and leading them to the Big Ten Conference Championship in 1931 and in 1933 and a Helms Foundation title in 1931. He had an overall 323-217 college coaching record at all three schools.
After he retired from coaching, he became chairman of the NCAA Tournament Committee from 1947–60, succeeding Harold Olsen. He was the U.S. Olympic team manager for the 1960 Olympics. He also served as Kansas Jayhawks Athletic director from 1950-63.
Lonborg was the head college football coach for the McPhersonBulldogs located in McPherson, Kansas. He held that position for the 1921 and 1922 seasons. His coaching record at McPherson was 10 wins and 9 losses. As of the conclusion of the 2010 season, this ranks him #10 at McPherson in total wins and #9 at the school in winning percentage (.526).