Is this altitude conversion tool bogus?

i have seen models that do show linear relationships up to about 8000 feet and then a slight non-linear relationship. Google scholar can probably get you the abstracts. Check to see what Peronent has written.

Thank you. For some reason I expected a non-contributory and caustic reply.

I have generally found their calculator to be useful (it's based on Daniels' tables, so it's got to be at least decent). I have noticed for very high altitudes that it doesn't seem to convert as accurately. Perhaps my acclimation has just never been exceptional at 10,000', but for someone like me with a mid-34 10k capability, I doubt I would only slow down by 2 minutes (as predicted) at 10,000'. I've done enough high altitude running to know that it would slow me down more than that...

Raptured wrote:

I have generally found their calculator to be useful (it's based on Daniels' tables, so it's got to be at least decent). I have noticed for very high altitudes that it doesn't seem to convert as accurately. Perhaps my acclimation has just never been exceptional at 10,000', but for someone like me with a mid-34 10k capability, I doubt I would only slow down by 2 minutes (as predicted) at 10,000'. I've done enough high altitude running to know that it would slow me down more than that...

The charts are obviously idealizations, but people aren't machines, and I'm guessing that the sheer distress of trying to milk top performance out of yourself at 10,000', with a huge mechanical breathing element involved (to the point where the work of breathing alone could contribute to overall fatigue) would slow even the toughest runners down more than low oxygen pressure alone would explain.

People run very slow at the Bolder Boulder, which is only at 5,300' or so, but the course is obviously a lot tougher than it looks, elevation considerations aside. No big hills but a bunch of grades.