OSLO - The Court of Arbitration for Sport Tuesday extended Norwegian cross-country skier Therese Johaug's doping suspension to 18 months, preventing the seven-time world champion from participating in the 2018 Winter Olympics. In February, Norway's sports board issued a 13-month suspension against her, who tested positive for a steroid which she said was in a lip balm, but the FIS deemed that decision too lenient and lodged an appeal. A 2010 Olympic cross-country skiing champion, Johaug tested positive for traces of the anabolic steroid clostebol, during an out-of-competition drug test on September 16, 2016. She said the steroid was contained in a lip cream called Trofodermin, which she had used to treat burns she received during a training session at high altitude in Italy in late August.