Fair enough, I haven't jumped out of a plane, I was basing it on my climbing experience, which I realise now is not a valid comparison, I suspect that it's more

Fair enough, I haven't jumped out of a plane, I was basing it on my climbing experience, which I realise now is not a valid comparison, I suspect that it's more noticeable in that context because of the high rate of respiration you tend to get when slogging it up big hills.