Ze,

Have you seen this one?

http://www.caloriesperhour.com/index_burn.php

do you think more calories are burnt during snow travel, given the same elevation gain and distance?

FortMental wrote:It's also true that energy source changes as a function of altitude; a very large amount of muscle is lost at altitude, even from just sitting around. As for total work done, the statement is irrelevant: the work required in lifting a 1Kg mass at sea level isn't (largely) different at 8,000m. However, it's the efficiency of the machinery that changes. That's probably where future research will go. Not biomechanical (hardware) but hormonal (software).

Interesting, I think I agree although I'm not sure the biomechanical / physiology areas have been exhausted either. Even if we can't tell what hormonal changes occurred, measuring VO2 consumption at different elevations would indicate the effect of those changes. Gotta look up those studies!

MikeTX wrote:basal metabolic rate affects how many calories a person would burn for a given activity. i'm not sure, but i think bmr increases slightly when at high altitudes. would it not then play a factor in calories burned?

I think this is what others are mentioning too, about altitude increasing metabolic rate even without additional work. Let's see the studies!

adventurer wrote:Ze,

Have you seen this one?

http://www.caloriesperhour.com/index_burn.php

Yeah there are plenty of sites that do caloric estimation for a bunch of activities. The thing is that none are hiking specific...they may have some generic hills / speed categories, but I just like providing all the options.

Even if the calorie estimate isn't as accurate as one would like, I like comparing the relative workload between different hikes. Eventually I'll add a table of some common hikes and how they "compare".

Castlereagh wrote:do you think more calories are burnt during snow travel, given the same elevation gain and distance?

I'm sure depends on the type of snow travel...firm snow vs postholing? This is why I added a "terrain" variable, but it is so vague right now I just took it out temporarily. Only way to quantify the real effect of all sorts of terrain is with a bunch of experimental data.