Magnus Konow took part in six Olympic Games between 1908 and 1948, winning two gold medals in 1912 and 1920 and one silver in 1936, and never placing worse than fourth. In 1936 he sailed together with his son Karsten and in 1948 with his two sons-in-law Ragnar Hargreaves and Lars Musæus. Konow also won the Gold Trophy five times and four times won the One-Tonner-Cup, winning the last of the latter in 1957 at age 70. As a student he joined the Royal Norwegian Yacht Club (KNS) in 1907 and was later a board member for two terms and vice chairman from 1937-40. He also fostered several technical improvements in sailing. As a young man Konow also practiced ski jumping and rowing.
After graduating Konow started learning paper production, then went to Buenos Aires to start an import business. He then returned to Norway, running an import-export business in Christiania (now Oslo). He became particularly successful as a co-founder and owner of A/S Rosshavet in Sandefjord with a license to hunt whales in the Antarctic Ross Sea. He even participated in whaling expeditions and shot several whales himself. During World War II, Konow, who married three times, emigrated to the United States and became an American citizen.