Background
Hertog was born to a Dutch father and Russian mother.
Hertog was born to a Dutch father and Russian mother.
He came third in the Olympic team time trial in 1972, but the team was disqualified for a doping offense. An accident with a car in the Belgian Ardennes on 17 August 1967 came close to ending his career. Den Hertog was considered the best amateur of his time, and many professional teams wanted him, but he declined out of fear to lose his freedom.
In 1974, Den Hertog finally turned professional but he had passed his peak.
He first rode the Tour de France in 1974. He dropped out with knee pain in the 13th stage.
He also rode for Lejeune-Boite Postale and the Belgian team, IJsboerke-Warncke Eis, but never with the success he had as an amateur. He opened a bicycle business in Dilsen in Belgium but closed it for "personal circumstances".
In 2007, he was diagnosed with prostate cancer, from which he died in February 2011.