Incorrect.
When you are exercising, you breath in and out so much air, that the buffer space in the mask is negligible.
The hocky player is over whelming the mask.
But when you go to the grocery store, the makes contains almost exactly the amount you inhale and exhale.
So that mean you are not getting any fresh air at all, but just breathing in and out the same air over and over again, while it slowly reduces O2 content, while increasing CO2 content.
You can tell because your body recognized the CO2 build up and releases panic hormones.
You feel like you are drowning.