I would add, as regards to filters. Make sure you take out the cap on the filter, or restricting the airflow is exactly what you will do. As you won't get any in at all
But I have to wear these masks regularily and out of choice I would not train with one on. Having lenses inside them is bad enough when doing tricky jobs let alone doing a gym sesh!
As has been said, it makes my workouts seem tame. I am going to have to raise my game!