In the 1904 Summer Olympics in St. Louis, Post won the gold medal in the singlestick and team foil competition, silver in individual foil and bronze in individual épée and individual sabre. Although from the United States, Van Zo Post was listed as representing Cuba in the Olympics. The majority (81%) of Olympic athletes at the 1904 games were from the United States, but were listed as representing various countries. Eight years later in Stockholm he reached to the quarterfinals in individual foil, individual épée and individual sabre and did not advance from first round in the team épée competition.