[Trombone-l] Altitude vs Lung Capacity?

[Galen Zinn]

I¹ve often heard that athletes, especially distance runners like to do their
training at high altitude because it seems to give them more endurance
(better use of air) when they compete at a lower altitudes.

Recently I had an opportunity to practice my Shires bass trombone at an
altitude above 6,225 feet, with a Yamaha Doug Yeo signature mouthpiece. I
really had a hard time filling up the horn and sustaining long tones,
especially in the low register. Does one loose breath capacity at altitude,
or was I just having a bad day?

Is there anything one can do about increasing their breath/lung capacity for
sustaining long pedal tones or are you pretty much stuck with the capacity
you were born with? I often find myself having to take extra breaths in
places that are less than the best for communicating musical phrases.
GRiZ