No, masks are just protection, not 100% isolation. Outdoor exercise needs a lot of oxygen, and the body function is in a state of exercise, and the cardiopulmonary function is much more active than sitting still, that is, one breath at ordinary times may be 1.5 times or higher during exercise.

If you still want to exercise in foggy days, it is best to exercise in a fitness place with a filter purifier indoors.

I think you should become a formal outdoor athlete. These days are not bad. It's not cost-effective to go out and take more drugs when you are in a bad mood.