I am a volunteer firefighter and once every year we have to pass a fitness test to prove we are physically capable of working as a firefighter. One part of this test is to do a sport program with a self-contained breathing apparatus (SCBA).
Now what I've noticed is that I need a lot more air than my colleagues, while I am quite fit: I exercise around 4-5h a week, divided into equal parts of cardio and weight-lifting.
Yet I need more air than slightly overweight smokers who only sparely exercise. Is there any technique or training method maybe divers use to minimize their air-consumption? (I am not quite sure which tags to use, so feel free to add or remove)