Quote Originally Posted by mr brightside View Post
Did some basic altitude simulation breathing exercises last night. Wasn't as bad as i'd expected, but the diaphragm spasms and throat cramp are a bit of a pain. 25s hold then one normal breath, 25s hold... So 30s for each cycle, did maybe 10 cycles, got my SpO2 down to 86%. Woke up with a headache this morning.
This may be of interest:

https://journals.physiology.org/doi/...rnalCode=jappl