they cause you to breath more deeply as they are obviously slightly restrictive
This doesn't make sense. You might have to try harder to achieve the same tidal flow if your air intake has a restrictor, but your total mass flow is guided by your autonomic engine management system in response to the requested power output.
But if you are already breathing heavily because of exercise, could the restriction then have an effect?
Wouldn't a better reaction to bad air to go a bit earlier and avoid major roads, poodle on back roads, keeping your breathing normal and staying away from large vehicles?
This doesn't make sense. You might have to try harder to achieve the same tidal flow if your air intake has a restrictor, but your total mass flow is guided by your autonomic engine management system in response to the requested power output.