In 1990 he signed professional terms and took part in the World Championships in Utsunomiya, Japan. He finished the World Championship course :08 behind the winner within a peloton of the best riders in the world including Gianni Bugno, Greg Lemond, Pedro Delgado, Sean Kelly and Miguel Indurain. He was later diagnosed with cardiac arrhythmia, which meant that he had to quit professional cycling. It was suspected that the cause of his health problems was the use of EPO. Professor Romuald Lewicki from Zakład Medycyny Sportowej WAM in Lodz (Institute of Sports Medicine) claims that Halupczok's