On 24 May 2007 Zabel and former Team Telekom team-mate Rolf Aldag admitted using EPO to prepare for the 1996 Tour de France . Zabel told at a press conference he experimented with it for a week and stopped due to side effects. He apologized for lying about using EPO in the past.  His confession was triggered by accusations by former Team Telekom masseur Jef d'Hont and the confessions of Bert Dietz , Udo Bölts and Christian Henn , all former members of Team Telekom. D'Hont's book, of which excerpts were printed in the German political magazine Der Spiegel in April 2007, accused members of Team Telekom of systematic doping with EPO in the mid-1990s.