american olympic 100 metres hurdles champion brianna mcneal will miss the tokyo games and even the 2024 paris olympics after the court of arbitration for sport cas dismissed her appeal against a fiveyear ban for an antidoping rule violationmcneal who had been charged and provisionally suspended for tampering within the results management process in january was sanctioned by the athletics integrity unit aiu as it was her second violation of world athletics antidoping rulesthe ban is effective from aug 15 2020 and will run until midaugust 2025 mcneal had appealed against the decision to cas which heard the case ahead of the tokyo olympicsthe cas panel dismissed the appeal filed by brianna mcneal and partially upheld the appeal filed by world athletics it said in a statement on fridaycas added that all mcneals competitive results from february 13 to august 14 last year will also be disqualifiedmcneal who won gold at the 2016 rio olympics and was world champion in 2013 had denied testing positive for any banned substancethe 29yearold led a us clean sweep of the 100m hurdles podium at the 2016 olympics but was banned for a year when she missed three outofcompetition drug tests which constitutes a rule violation that ban which was applied for the 2017 season resulted in her missing the world championships that year