High altitude.

Today is be frank... Was absolutely brutal!!!! We ascended 1200m in about 6km, that's the high of Ben Nevis but we started from camp at twice the height of it at 2700m

Click click thud thud puff puff...
Click click thud thud puff puff...
Click click thud thud puff puff...

That was my constant companion for the day, at 3000m it became
Click click, thud thud, puff puff puff puff as the altitude kicked in and more oxygen was needed. The only way I can describe the effects of the altitude is to compare yourself to being totally unfit, you've just eaten a whole bargain bucket of KFC at the end of a really long week and now you are trying to run up a hill with a pounding head ache! Apart from my ML training expedition this is physically the most demanding day of my life!