First, wearing a mask is a good thing. think asymptomatic – they never show symptoms – or pre-symptomatic – sick but not yet feeling it.
Second, think timing and location. Pick a time and place where you won't likely be in close contact with people. You don't want to be directly behind one person for an extended period of time. They could be exhaling or coughing or spitting out infectious droplets. Keep double social distance (12ft) so you can focus on your run, ride or walk.
Third, keep your hands to yourself. Don't touch "high-touch" areas by avoiding them. Part of location too.
When you finish your activity, wash your mask out thoroughly with soap and water. And wash your hands, too. Because ... it can't hurt!
BE SAFE, BE AWARE, BE VIGILANT, WEAR A MASK! ©