Amelia Boone, a world champion obstacle racer, shared the incident on Twitter She said she was running outside on April 25 when someone yelled at her for not wearing a mask when she ran past them 'I think it's time we normalize not wearing masks outside,' she wrote in the tweet Boone, who says she is fully vaccinated, wrote that she is 'absolutely 100% pro mask' and will likely 'continue wearing them on planes indefinitely, for example' Last week, the Centers for Disease Control and Prevention (CDC) announced that fully vaccinated Americans can now safely go without masks outside As long as they are outside, people who are fully vaccinated can exercise, go to small gatherings or restaurants with people who are vaccinated or unvaccinated