Skyline vs Marathon - Time comparison

[tinaballina]

Being asthmatic makes it hard for me to do marathon runs but going up skyline is no problem. I can't run up the trail but i move pretty good when i want to. my best time (not running) is 4>21.
I would like to break 4 hours this coming fall and i am not planning to run it.
When you guys are talking about best time up vivian, are you just speaking of vivian to the peak?

[AlanK]

When you guys are talking about best time up vivian, are you just speaking of vivian to the peak?

Yeah -- parking lot to summit. At least that's what I meant.

[zippetydude]

I define Skyline as passing through the wall at the back of the museum parking lot to passing through those two boulders at Grubbs Notch.

I clock Vivian from the trailhead sign in the parking lot to the peak.

My best times on each have a similar ratio to what others have posted. Skyline takes me about 1.33 times as long as Vivian, or to put it conversely, Vivian takes me about .75 the amount of time that Skyline does. Given a 4:21 Skyline, your predicted time for Vivian by those ratios would be about 3:15. Is that close to your actual time on Vivian?

z

[tinaballina]

I define Skyline as passing through the wall at the back of the museum parking lot to passing through those two boulders at Grubbs Notch.

z

Those two boulders are my mark as well.

[Zé]

Here's an estimate of energy expenditure for a 70 kg person: Calories burned = [95 Cal * distance in miles] + [0.15 * elevation gain in feet]

Skyline: 11 miles and 8000' gained ==> 2250 Cal

Marathon: 26.2 miles on the flat ==> 2490 Cal

Where did you get your equation from. Or what derivation did you use?

I have some 5th order polynomial equation lying around for both "walking" on grade and running on grade from a research paper. maybe in a few days i'll run an analysis with those.

actually if i had a heartrate monitor that could record a lot of data, I would experimentally test this stuff. but i don't want to buy a garmin forerunner just for that.

Great questions. Difficult to answer. I think Skyline is equal to or longer than a flat marathon time, depending on a person's running economy and training specificity.

yeah i would like to compare the case assuming the person is 'equally' adapted for both modes. when i used to run a lot of flat ground, i could do a flat half-marathon in 1:25. the baldy race i did in 1:30, but I was certainly a bit more adapted for flat running (overdeveloped hamstrings).


i'm glad there are a few cases out there (Perry, zip) who have done both marathon and skyline.

[AlanK]

Here's an estimate of energy expenditure for a 70 kg person: Calories burned = [95 Cal * distance in miles] + [0.15 * elevation gain in feet]

Skyline: 11 miles and 8000' gained ==> 2250 Cal

Marathon: 26.2 miles on the flat ==> 2490 Cal

Where did you get your equation from. Or what derivation did you use?

A few years ago there was a discussion of energy expenditure on the Whitney board. At one point I found a couple of articles in the Journal of Applied Physiology and some version of that equation came from fitting the data in one of them. I have subsequently seen data that do not agree all that well with the fit (or the original data I used). I would not advertise any particular equation as more than a decent estimate. I am not a physiologist and do not claim to understand all of the differences between various measurements, but treadmill experiments and "real life" are obviously different.

I did come up with a derivation at one point. One sees something like 80 - 95 Cal/mile on the flat in a lot of places. You can calculate a number in that range if you assume 25-30% efficiency for the human engine and worry about lifting ones legs (and center of mass) against gravity. It's easier to get the energy expenditure with elevation gain because it's basically just lifting one's entire mass against gravity (again, with an engine that's 25-30% efficient).

This is from memory -- I need to dig out my ole notes sometime.

By the way, I make no claims to originality in any of this. Many people have thought about this subject. I have not read many of them, but they were still there earlier.

[Perry]

Equations might work on average, but certain individuals will have different results.

4>21

Tina, 4 is less than 21.

[tinaballina]

Equations might work on average, but certain individuals will have different results.

4>21

Tina, 4 is less than 21.

Yeah yeah, i hit the wrong key that should be 4:21.
As you mentioned in an earlier post in order to do good time, everything has to be taken into consideration, especially the weather. that can make or break your time indeed.

[James]

I'm confused. My best Skyline (although I haven't done too many) is 5:15 yet my best Vivian is 3:30. These are one way times, trailhead to Grubb's Notch for Skyline and trailhead to summit for Vivian. These are both hiking, not running. And Skyline is mostly in the dark when it's cooler.

Not that I need a really fast Skyline time, I'm just wondering how I can go that much better on Vivian. Must have had a better breakfast that day.

[AlanK]

I'm confused. My best Skyline (although I haven't done too many) is 5:15 yet my best Vivian is 3:30. These are one way times, trailhead to Grubb's Notch for Skyline and trailhead to summit for Vivian. These are both hiking, not running.

I would expect a lot of individual variation. For one thing, Skyline is a desert hike for several miles, while vivian is not. On the other hand, if you slowed down by 1/3 from Vivian, your 3:30 would convert to 4:40. I'll go out on a limb and predict that you will do that on Skyline now.

P.S. I corrected the typo that FIGHT ON and Hikin Jim commented on below.