Do short hikers have to work harder to cover the same amount of distance?

[WalksInDark]

Okay, let me start out with the fact that this is not an earth shattering question. :D But it is a question I ask myself whenever I find myself the last person in the hiking string...even though I am moving my legs at a much faster pace than the tall folks who are ahead of me.

As a short(er) hiker (5'5") I know that my stride covers substantially less distance than, say, the 6'4" guy who leads a number of my outdoor enthusiast backpacking trips. So my question, for your engineers and rocket scientists out there is this: how would I calculate ---over the course of a mile--- how many more strides (ergo more effort) am I expending then the trip leader? Alternately, assuming that the short hiker (me) and the tall hiker (him) both take the same number of strides...how far behind him am I going to be after hiking one mile (a percentage will suffice)? :-?:-?

Thanks!

BTW, I probably should have asked this question under the "Slow Hikers" thread!

[Datto]

You'll be 30% behind with the same number of strides across a flat treadway.

However, the 6'4" person will likely experience more sway when carrying a backpack on uneven terrain (your center of gravity will be much lower so may not have as much sway on uneven terrain). That accounts for extra energy as a hiker is moving on an uneven treadway.

That may be why one of the reasons why short people (say 5'-2" in height) can complete an AT thru-hike just as much as a tall person.

I haven't seen any study of thru-hiker height or starting weight but that might be an interesting study.


Datto

[rickb]

Short skinny people win all the marathons.

Why shouldn't they hike faster and stronger too?

[Pendragon]

Well, I was short and skinny (but over 55) and I CRAWLED up those hills. THEN, I'd zip right past all of them on the downhills. Of course, that only lasted about 100 miles before the ankles and knees went on strike and cut my downhill slalom runs to about half that speed.........

[Slo-go'en]

There are 63,360 inches in a mile. Lets say a 6'4" guy has a 24" heal to heal stride. Chances are your stride isn't too much shorter, lets say you have a 23" stride, an inch less.

Therefore 63,360 / 24 = 2,640 steps and 63,360 / 23 = 2,754 steps. 2754 - 2640 = 114 extra steps, about a 4% difference. With all else equal, you'd have to walk just a tad faster then the tall guy to keep up. If you both had the same pace, the tall guy would out distance you about 200 feet for every mile.

[Bronk]

http://www.pedometersusa.com/cwmulti.html?productid=cwmulti&channelid=FROOG&utm_source=CSEs&utm_medium=GoogleShopping&utm_campaign=PedometersUSA&gclid=CK3658iBi7gCFSJqMgodcnYAbw




Try using a pedometer...it will measure how many steps you take...walk a mile and then reset it and have your tall friend do the same thing and then compare the results.

[Theosus]

Physically it should be the same amount of work. Moving X pounds across X distance requires X amount of work, regardless of stride length. The taller, longer-legged person will take a longer step, but has to hold the weight up on one foot for that longer step. The taller person may benefit from less knee impact because they take fewer steps, however their quads and calves will suffer instead of the knee joint. The human step is sort of a slightly up and down/side to side sway, like someone else mentioned. The taller person's pack weight sways a little more side to side, and moves up and down slightly more, whereas the shorter persons pack would move through a smaller range of up/down and side/side motion.
At least in my head.

[bear bag hanger]

As a 5' 6" hiker, I'm pretty sure tall people have a lot more than a one inch stride increase from me. I'm slow by nature and can not keep up with most people, but tall people in particular. I know plenty of short people who can hike a lot faster than I, but all of them have to move their feet a lot faster than tall people do.

[Mrs Baggins]

At 4' 10" I find this fascinating :) I am very slow on ups but I can go downhill at a fast trot, no problem. My height only becomes an issue when there are rocks or big tree roots that are "steps" going up or down. My husband is 6' 1" so a rock that is 18" high off the ground is about 1/4 of his height but a full 1/3 of mine. Add the weight of a pack to that step up or down and it gets very difficult with short legs. On flat ground I'm pretty fast and generally ahead of others I'm walking with.

[rickb]

I googled this up. Might the theory also apply to hiking. Full article here http://www.theglobeandmail.com/life/health-and-fitness/fitness/do-you-have-the-body-type-to-run-a-marathon/article586440/



There’s one thing that all great marathon runners have in common and no, it’s not a Kenyan passport. (That helps, of course.)


But watch the first people to cross the finish line and you’ll see that there’s one common denominator of long-distance dominance: size. Almost without exception, elite marathon runners stand 5-foot-7, give or take two inches, and weigh 140 pounds, plus or minus a few pounds.


“There is a reason that most elite marathon runners are of moderate height and very thin,” says Richard Hughson, a professor of kinesiology at the University of Waterloo and former world-class distance runner. “Running at high speed requires a lot of energy. Just imagine running with two two-kilogram weights in your hands or tied around your waist. If a marathon runner is four kilograms overweight, then he or she must carry that extra ‘useless’ weight for 42.2 kilometres. Therefore, all elite runners will have as little fat, bone and even muscle as possible.”


Athletic performance can boil down to physics, with body type determining how well you will do out on the track, or the court or the pitch. When it comes to running, smaller individuals with slight frames will almost always do better than their bigger, bulkier peers, no matter how good their biomechanics or training. With less load to carry, smaller runners are simply lighter on their feet.

[moytoy]

Everything else being equal (which they never are). A tall hiker should use the same energy as a short hiker to cover the same ground. How fast you can do it has many influences.
I suspect that the overall condition of your body has more to do with how fast you can hike than anything. Things like total body weight, joint condition, lung capacity and body fat just to name a few.

[poopsy]

I've been thinking and working on this for a while.

I agree that to cover the same distance on the flat it should essentially take the same amount of effort for the same weight. That said we should note that while marathon runners tend to be shorter, long distance speed walkers are not. Olympic walkers tend to be tall, but that is on the straight and level.

When it comes to the animal world, a good pack animal for rough country is a mule or a burro. You wouldn't want a thorough bred horse to ride up a mountain (or down one). On the other hand a moose has very long legs but a wild boar's legs are as stumpy as you can get.

I guess my conclusion is that shorter-legged (and lighter) people tend to have mechanical advantage when carrying weight over rough country as long as it they aren't going thru swamps. However, on smoother terrain with a light pack I'd want to have long legs. If I have to step over dead fall all day, I'd also want long legs. On developed trails, with an ordinary pack I don't think your height makes much difference. More important issues are how much you weigh, the size of your pack, your conditioning and your age.

[litefoot2000]

Yes, it's true that elite runners are compact with very low body fat. Ectomorphs, if you will. As a general rule, this seems to always hold true. However, in 2000, there was a thru hiker named Papa Smurf who had all of the characteristics of a fast runner or hiker. He was the slowest in the group. When it comes down to it, I think everyone is an experiment of one. If you don't have a V8 engine driving it, it makes little difference what the body type.

[Old Hiker]

I agree with a post above: as a Science teacher, I teach that mass moved is the same work regardless. That's why we use ramps, to lower the exertion, not the amount of work. My classes have done labs on this. It's how fast you take your steps to cover the distance that makes you faster.

That being said: there is also the incentive value. Coming down Springer after a multi-day trip, my wife was dragging behind me about 50 yards. I didn't really want to spend another night in the woods. I told her if we made it down before dark, I'd spring for a motel room with a jacuzzi bath. She's 5'2. I'm 6'2". She beat me down the mountain by 10+ minutes.

[Odd Man Out]

The human walking gait is usually described as an inverted pendulum. A pendulum needs very little energy to keep it swinging because the work needed to lift the pendulum against the force of gravity on the upswing is provided by the work provided by the drop of the pendulum on the downswing. Likewise, the bobbing of your mass up and down while walking on level surface is not necessarily the source for the consumption of most energy when walking. An implication of this principle is that carrying added weight need not cause a proportional increase of exertion when walking over level ground, but to negate the effect of added weight, you need to carry the load centered over your COM. As a result, African woman can carry 20% of their body weight on top of their head over level ground with no increase of exertion (oxygen consumption). A similar effect has been measured in Nepalese porters using a strap to transfer weight to their head. Also, it seems you need the right tools and skills. Europeans carrying the same loads in backpacks do not enjoy this benefit. Even when using the same methods, Europeans could not reproduce the efficiency of the native porters.

http://www.uclouvain.be/cps/ucl/doc/iepr/documents/loco_rec6EN.htm

You should also note that a pendulum will have a fixed frequency of swinging based on its length. This explains why each person has an optimal frequency for their walking gait. I also found this paper that expands the pendulum model for walking with the assumption that most of the energy exertion is needed to transition from one leg to the other. The angle at which this happens is determined by the length of the gait which correlates to the amplitude of the pendulum swing. Also, they model the fact that your step pendulum also swings from side to side as determined by your step width. The mathematical analysis of the model confirms the observation that each person has an optimal step length, frequency, and width.

http://www-personal.umich.edu/~artkuo/Papers/ESSR05.pdf

[WalksInDark]

Fascinating stuff! Thanks everyone.

[daddytwosticks]

Yes, all good information. But let's not forget short/skinny peoples' packs are much lighter (all things being equal) than a tall/stout person. Tiny hikers carry short sleeping bags, smaller pads, shorter shelters, and lighter clothes due to the size issue. Not to mention ducking under blowdowns takes less energy than a taller hiker. This being said by a six foot, 185 pound hiker. Midget hikers rule! :)

[max patch]

I don't know the answer.

But I do know that neither me nor anyone else can change their height.

So I'm not gonna worry about it.

[Datto]

I've been thinking overnight about the question you posed yesterday. A very interesting question to me to say the least.

From a long-distance hiker perspective, the weight of a backpack on a long-distance hiker has, in past years anyhow, tended to be about the same regardless of height. Reason -- there isn't much of difference in the items carried and the corresponding weight difference item-for-item that a short person carried versus a tall person wasn't much of a difference.

However, what I have witnessed that makes a big, big difference and evens the playing field between a short hiker and a tall hiker on a thru-hike of the Appalachian Trail are these things (cumulatively or individually, ranked in order of most impact first):

1) Drive
2) In-trail-shaped-ness
3) Number of hours hiked per day
4) Pain sensitivity
5) Over-enjoyment of town days

Example: Harriet Tubman was in premo physical shape when she started the Appalachian Trail at Springer Mountain. Additionally, she was driven. She's about seven inches shorter than I. Her pack weighed 50+ pounds while mine was around 37 pounds or so in Georgia/North Carolina. Me, i was in pretty good trail shape starting my AT thru-hike but I like to take naps every day and stop and take photographs, keep a journal and visit with others frequently. Harriet Tubman would consistently arrive at the shelter for the night before 3:00pm that she and Mac had agreed to in the morning while Mac and I would arrive sometime north of 7:00pm. So in that case, in-trail-shaped-ness and drive made a considerable difference for a hiker and height didn't make that much of a difference.

Also, Keebler for instance, who was a petite woman -- she had started her hike of the AT in the previous year and when I started my hike the following Spring, she would simply blow past me on the uphills (her pack weight, as you might have gathered from her trail name, was considerably lighter than mine and given that she'd already had about a thousand trail miles under her belt).

Another hiker I'd met up with (a southbounder) was 5'-2" and I'm thinking her weight was I'm guessing under 110 pounds. I was surprised to have found that her pack was 39 pounds when we'd met while mine was around 30 pounds at that time. She too could crank out miles if need be and finished her southbound AT thru-hike. I think, had she been a northbounder, we would have been cranking out about the same amount of mileage per day had we both been going in the same direction even though I'm almost a foot taller than her.

I also noticed that I enjoyed town days -- maybe disproportionally more than the average thru-hiker who'd been hiking for more than 1,000 miles. That, heh, you could say, slowed my northbound thru-hiker progress a little. As I traveled northward on my AT thru-hike, the Trail really became my home and the noise in town was deafening sometimes, still I enjoyed the diversity town offered from normal trail life (and I am one who immensely enjoyed time on the Trail on my AT thru-hike).

That's why I say, for a long-distance hiker there are things way more important than just height and stride length in the equation.

One other thing -- I hadn't realized this until Maine on my AT thru-hike -- looking for blazes at the front of a group of hikers takes more energy than you think it would. When I hiked behind a couple other hikers in Maine (so I wasn't at the front looking for blazes and instead, just hiking behind the hiker in front of me), I noticed I was expending noticeable less energy on hiking. That may be due to the fact that I absolutely abhor having to backtrack (more so than other hikers and that was true even when I'd reached Maine -- possibly that's due to me being a planner type and unexpected things like having to backtrack are seen disproportionally as wasted effort).

Then there is the element of diet. Somewhere about Connecticut and Massachusetts I begin to notice there were attitude problems from some of the people I'd had met up with along the trail. Bad enough attitude problems that they were thinking of leaving the Trail and going home. Why I remember this is that I'd tried to talk them out of it so I had to ask them what the problem was. I honest think those people may have had a problem with diet and over the course of an AT thru-hike, the long-term effects of a bad diet had swung their mood. I don't think it's equivalent to the impact of say in-trail-shaped-ness or hours hiked per day or pain sensitivity but still, enough that I'd thought it was important over the long haul of an AT thru-hike because it could affect a thru-hiker's drive and mood.

An interesting topic.


Datto

[Datto]

Also, finances. The impact of finances, once a thru-hiker had reached say $5,000 set aside for their AT thru-hike, didn't seem to be that important in the scheme of things for an AT thru-hike. I imagine the chart of effectiveness of finances on completing an AT thru-hike plateaus at $5,000 and hockey sticks up to that point before plateauing. For a short hiker, having more money set aside wouldn't seem to make up much of a difference to level out the playing field when compared to the natural advantages a tall hiker would have. Drive, in-trail-shaped-ness and hours hiked per day would seem to make a much more significant impact to level the playing field between a short hiker and a tall hiker on a long-distance hike.


Datto

[atmilkman]

There are 63,360 inches in a mile. Lets say a 6'4" guy has a 24" heal to heal stride. Chances are your stride isn't too much shorter, lets say you have a 23" stride, an inch less.

Therefore 63,360 / 24 = 2,640 steps and 63,360 / 23 = 2,754 steps. 2754 - 2640 = 114 extra steps, about a 4% difference. With all else equal, you'd have to walk just a tad faster then the tall guy to keep up. If you both had the same pace, the tall guy would out distance you about 200 feet for every mile.

Pace effects my stride. I'm 6'6" tall. I take between 530 and 560 strides per ¼ mile. At 3¼ mph I take 560 strides per ¼ mile. At 3½ mph I take 530 strides. This is ideal conditions on a manicured wood chip trail. No gear, just walking. On the trail throughout the course of a whole day I average much less. Usually between 1½ - 2 mph. All stops and dilly-dallying included.

[Pedaling Fool]

The human walking gait is usually described as an inverted pendulum. A pendulum needs very little energy to keep it swinging because the work needed to lift the pendulum against the force of gravity on the upswing is provided by the work provided by the drop of the pendulum on the downswing. Likewise, the bobbing of your mass up and down while walking on level surface is not necessarily the source for the consumption of most energy when walking. An implication of this principle is that carrying added weight need not cause a proportional increase of exertion when walking over level ground, but to negate the effect of added weight, you need to carry the load centered over your COM. As a result, African woman can carry 20% of their body weight on top of their head over level ground with no increase of exertion (oxygen consumption). A similar effect has been measured in Nepalese porters using a strap to transfer weight to their head. Also, it seems you need the right tools and skills. Europeans carrying the same loads in backpacks do not enjoy this benefit. Even when using the same methods, Europeans could not reproduce the efficiency of the native porters.

http://www.uclouvain.be/cps/ucl/doc/iepr/documents/loco_rec6EN.htm

You should also note that a pendulum will have a fixed frequency of swinging based on its length. This explains why each person has an optimal frequency for their walking gait. I also found this paper that expands the pendulum model for walking with the assumption that most of the energy exertion is needed to transition from one leg to the other. The angle at which this happens is determined by the length of the gait which correlates to the amplitude of the pendulum swing. Also, they model the fact that your step pendulum also swings from side to side as determined by your step width. The mathematical analysis of the model confirms the observation that each person has an optimal step length, frequency, and width.

http://www-personal.umich.edu/~artkuo/Papers/ESSR05.pdfI like this post and, in part, it's also very applicable to the "Help me define "2lbs."" thread:)

[Mrs Baggins]

Yes, all good information. But let's not forget short/skinny peoples' packs are much lighter (all things being equal) than a tall/stout person. Tiny hikers carry short sleeping bags, smaller pads, shorter shelters, and lighter clothes due to the size issue. Not to mention ducking under blowdowns takes less energy than a taller hiker. This being said by a six foot, 185 pound hiker. Midget hikers rule! :)


Both my husband and I end up carrying about exactly the same weight - right about 26 lbs - in our packs. We have identical bags, pads, tents, stuff sacks, cook gear, eat the same foods, carry the same water bladders.......

[Odd Man Out]

I like this post and, in part, it's also very applicable to the "Help me define "2lbs."" thread:)

I had a fun morning looking stuff up.

BTW, the first author of the second paper I cited has a more recent publication where he analyzed people who walk without an up and down motion. If you want to see an extreme example of this, visit the Tomb of the Unknown Soldier at Arlington NC. The guards walk back and forth with no head bob at all. If you watch only their top half, it looks like they are riding a conveyer belt. Anyway, the study found that this type of walking is much more energy demanding so the up and down motion is helpful, as predicted by the pendulum model.

But the original question goes unanswered. A short person will take shorter steps, and thus take more steps per mile. But that does not mean they necessarily walk slower as they may also have a lower step frequency, just as a shorter pendulum swings faster. After all, when my Corgi was young, her could run and walk a lot faster than me and his legs are this long:

|--------------------------------------------------------------|
Corgi Leg

Also, more steps per mile doesn't necessarily mean more energy consumption per hour or per mile. I will have to look into it more.

I'm tempted to start carrying stuff on my head too.