Haase trained with methods developed by
Arthur Lydiard, the New Zealand trainer who was, at the time, still relatively unknown in Europe and was the surprise winner of the 1965 GDR 10,000 metres. At the European Championships in 1966, his teammate
Jürgen May convinced him, with the help of a $500 bribe, not to wear his usual
Adidas shoes but rather to wear
Puma. This episode became something of a political scandal, in the course of which Haase was pardoned by the GDR Sports authorities. May, on the other hand, was permanently banned from the GDR national team. Haase won the British
AAA Championships title in the 6 miles event at the
1967 AAA Championships. Haase missed the
1972 Summer Olympics due to
blood poisoning that he received after being injured by the
spike of another runner at a competition in Paris. After retiring from competitions in 1973, Haase was active in customer service and marketing of medical technology. He then graduated from the
Deutsche Hochschule für Körperkultur und Sport (German College for Fitness Training and Sport) and became a coach at
SC Dynamo Berlin. His trainees included
Kathrin Weßel (bronze medalist in 10,000 m at the 1987 World Championships) and
Detlef Wagenknecht (World Cup medalist in 800 m in 1981 and 1983). After the
reunification of Germany, Haase worked at the Deutschen Leichtathletik-Verbandes (German Track Federation). ==International races==