He is a two-time winner of the World's Strongest Man competition in 1977 and 1978 and the author of numerous strength-related articles and books.

He continued his athletic development at Stanford University, competing in shot, discus and wrestling.

He finished 4th in the 1966 AAU National Freestyle Wrestling and Greco Roman Championships (unlimited weight class).

After one year at Stanford, Wilhelm transferred to Oklahoma State University where, in addition to throwing the shot, he was a member of the varsity wrestling team.

[3] Wilhelm is still is #251 on the all-time world shot put records, with a mark of 20.12m (66'-1/4") set on July 8, 1972, during the Olympic trials.