Canadian doctors do ballet dance moves in N95 masks to show it's easy to breathe, and breathe *heavily*, in them: https://boingboing.net/2023/09/19/canadian-doctor-dancers-demonstrate-how-easy-it-is-to-breathe-in-an-n95-mask-respirator.html

I co-sign! Back in the first nasty pre-vaccine summer of 2020, I cycled 100 miles in a day from NYC to Philadelphia, wearing a mask the entire way

It's actually a wonderful way to protect from gnarly traffic fumes!

And yeah, even with my heart rate up high most of the way, no trouble breathing