NandaDevi;

There is no good formula for the lowering of AeT pace as you go up in altitude. We can only say in a qualitative way that it will drop and we have much anecdotal evidence from climbers recorded HRs at high elevation. I discuss this in some detail here

David Goettler and Ueli Steck Put Low-Intensity Training to the Test in the Khumbu

Note that David’s HR was about 20 beats below his low elevation AeT for this climb at 6100m despite the perceived effort being higher than AeT at sea level. Assume some thing similar for yourself.

I hope this helps.

Scott

I just returned from the Khumbu, and found that I didn’t exceed a HR of 120 even during some higher-output efforts (ie watch for yaks!) and at Everest Base Camp, didn’t get above 110. Sometimes my exercising HR was at or below my resting HR, which was curious- but often happened after a night of poor sleep or when battling respiratory irritation due to cold dry air. I also followed the 16 week mountain training plan and found that I acclimated well (with proper ascent timing), felt strong and had the energy to go all day for multiple days on end. I was really thankful for the amount of time I spent training at the lower end of my aerobic zone- as I think it was a major factor in feeling good up there.