Dec 23, 2015 at 5:37 am #3371977Ito JakuchuBPL Member
I would love to give a small summary, but like the last seven years, somehow right before X-Mas I get a lot of new assignments.
A small excerpt:
“… as it turns out, there’s a range of slope angles that allow athletes to ascend a mountain most quickly … for either running or walking, slopes between 20 and 30 degrees require the same amount of energy to climb at the same vertical velocity. In other words, there’s an optimal range of slope angles where the degree of incline doesn’t matter, and where the same rate of ascent requires the same rate of energy expenditure. The researchers are calling it the “Goldilocks Plateau.”
See:Dec 23, 2015 at 8:46 am #3371993Daryl and DarylBPL Member
@lyrad1Locale: Pacific Northwest, USA, Earth
Thanks for the post. I also find it fascinating.
Perhaps trail builders should consider this info. Most new trails are below the 20-30 degrees considered optimum in this study. The older trails are steeper. Maybe the miners and trappers who blazed some of the original trails new best?Dec 23, 2015 at 9:59 am #3372009
Nowadays the new trails have to be ADA compliant. ;^) There’s also a good argument that there’s far less erosion on shallow-angle trails.
But that is interesting that 20-30° angle observed no increase in energy expenditure.
Since we don’t really have any control over trail steepness — at least not the ones already in existence — wouldn’t it be better for individuals (your average mortal, not the trail running gods) to base effort on percentage of maximum heart rate or perceived effort?
People engaging in long FKT events can’t be pegging the redline all the way, no?Dec 23, 2015 at 10:36 am #3372018Daryl and DarylBPL Member
@lyrad1Locale: Pacific Northwest, USA, Earth
This article talks a bit about women carrying loads on their heads with no greater energy expenditure than walking without a load. Seems related to this topic of efficient movement.Dec 23, 2015 at 11:07 am #3372028Jerry AdamsBPL Member
@retiredjerryLocale: Oregon and Washington
Interesting. It seems intuitive that the steeper the slope the faster, because you have less horizontal distance.
Yeah, they make trails less steep for erosion control. Straight uphill – trail turns into a stream. If you go half way between straight up, and traversing sideways, then water will tend to just flow across the trail. If you want to go straight up you get switchbacks.Dec 24, 2015 at 8:22 am #3372186Dave GreyBPL Member
For those who are interested,
http://iancorless.org/2015/12/22/running-or-walking-efficiency-when-climbing/ discusses this study, and another one which (still using top-end runners) also tests at differing speeds, and measures energy expenditure on negative gradients as well as positive.
For a point of reference the fixed climbing rate in the originally mentioned study was 0.35 m/s, the world record for the Vertical kilometre is just under 30 mins, about 0.56 m/s average.
DaveDec 24, 2015 at 4:33 pm #3372284Ito JakuchuBPL Member
I really like the articles on iancorless.org, especially the ones by Marc Laithwaite, but hadn’t seen that one yet.
Will read it more closely when I can, but looks very interesting.Apr 6, 2016 at 9:23 pm #3394437Todd TBPL Member
@texasbbLocale: Pacific Northwest
Gak! 20 to 30 degrees is steep. That’s between 36% and 58%, or 2000 to 3000 ft/mile. Not sure I buy it.Apr 7, 2016 at 5:15 am #3394488
For sure, the more you think about it the more something seems ‘off’.Apr 7, 2016 at 7:28 am #3394508Greg MihalikBPL Member
You think the science is flawed, or you can’t comprehend walking up something that “steep”?
There is a reason they are called extreme athletes.Apr 7, 2016 at 8:36 am #3394518Todd TBPL Member
@texasbbLocale: Pacific Northwest
“You think the science is flawed, or you can’t comprehend walking up something that “steep”?”
I can’t comprehend that being the most efficient slope for gaining vertical. But I ain’t no extreme athlete, either.Apr 7, 2016 at 8:36 am #3394519
Well, it is interesting that the men’s and women’s VK records were set on the Fully course in Switzerland with an average slope angle of 27.5°, which also happens to be the steepest official VK course.
It’d be enlightening to hear the thoughts of elite ultra runners on whether this applies to much longer times and distances.Apr 7, 2016 at 9:30 am #3394530Greg MihalikBPL Member
“I can’t comprehend that being the most efficient slope for gaining vertical. ”
I don’t think anyone is saying that those angle are the most efficient for getting to the top, only that –
“… for either running or walking, slopes between 20 and 30 degrees require the same amount of energy to climb at the same vertical velocity.”
Perhaps there are other “sweet spots” for the common man – e.g. the same amount of energy to climb slopes between 5% and 10%.Apr 7, 2016 at 11:23 am #3394544Nick GatelBPL Member
@ngatelLocale: Southern California
Theories are interesting and sometimes real world applications don’t pan out. Each of us is different, with different levels of fitness, etc. There was a recent “tortoise and hare” thread where the general consensus was a steady pace works best.
We can look at cross country racing strategies, where courses are generally 8K to 10K in length, or we can look at ultra marathons where runners run and/or walk. Andrew Skurka has some detailed ultra running plans, training strategies, and post race analysis on his website and has done well in several races. Probably a good read for someone who wants to take a look at the science and the applied and isn’t looking to win some sort of World Championship.
For a general rule in cross country for which I have a lot of experience, a runner wants to go up hills at a steady pace without getting exhausted in the effort. Remember, “What goes up must come down,” so really good cross country runners will pick up speed on the downhills and let gravity assist to the point of not losing control — this is a learned skill. This is how cross country races are often won — stay in contact with the lead pack, maintain a reasonable and steady pace on the uphills, pass competitors on the downhills, and keep enough energy in reserve to pass competitors on the flats or any possible sprints to the finish. It’s all about proper pacing throughout the entire race and the ability to adjust the pace over any given terrain or weather conditions.
For us mere mortals I can only share ancedotal experience. When I am in great shape I can do long stretches of constant elevation gain at a steady pace, such as 8,000 feet elevation gain in 11 miles, which is less than 1,000 feet per mile. Sections that are steeper than this require a slower, but constant pace. But it all comes down to physical condition. When I am in great shape, I move the fastest, at the steadiest speed, and have little or no recovery time needed. When I am not in great shape, I cannot hike long inclines without an occasional rest. Lots of elevation gain means fewer miles per day for me.
But I don’t pick trails based on trail construction methods, number of switch backs, elevation gain, etc. I usually just want to get from point A to point B in a specific amount of time, because I am hiking somewhere that is chosen for specific attributes, other than a particular trail or cross country route.
Today most elite runners get involved with technology and measurements such a heart rate, pulse, VO Max, etc. As a hiker I just want to walk, and all the science takes away or distracts from the fun. If I can learn from experience what pace works best for me on specific terrains, and if I can plan my daily mileage based on the conditions, and hit the distance milestones on time to get from A to B as planned, I am happy. Others want the science to guide them, which is okay if it works for them.
I have a friend who is has extraordinary intellect and is a competent engineer. I took him on some of his first backpacking trips. He would walk behind me on the uphills and analyze my foot placement (mostly toe first he pointed out), length of gait, pace, etc. Mentally he wanted to develop the most efficient method of walking. I finally persuaded him to stop thinking about it and just look at trees, plants, and the world around him. He is now a much happier hiker, enjoys his trips more, and simply walks without thinking about it.
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