Since 1933, Otto Adam was one of the top German fencers, mainly with the foil. Although he reached the finals of 10 consecutive German Championships he never won an individual national title. His greatest success came in 1936, when he was a member of the German team that won the bronze medal at the 1936 Berlin Olympics. In 1954, at the age of 44 he was runner-up with the foil and third with sabre at the German Championships.
After World War II, Adam was one of the founders of the Saar Fencing Association, which was represented by a separate team at the Helsinki Olympics. From 1952-74 he acted as President of the Saar Fencing Association. In 1957, after the Saar was re-incorporated into the Federal Republic of Germany he won the election against his former teammate and predecessor Erwin Casmir to become President of the German Fencing Association, a post which Adam held until 1970. After his years in office, he was appointed Honorary President of both, the Saar and German Fencing Association. For his achievements, Adam was awarded the Order of Merit of the Federal Republic of Germany. His business was running a company that produced glass eyes.