TREADMILL VERSUS OVERGROUND RUNNING TECHNIQUE

June 27, 2005

TREADMILL VERSUS OVERGROUND RUNNING TECHNIQUE

In response to an ongoing debate on Pose Tech's Forums

Pieter, your hero, Benno Nigg, as you quoted, made a statement that "It is not yet understood how the human locomotor system adapts to a particular treadmill running situation". Nevertheless, you are questioning: "How can this be different in biomechanics?"

Biomechanics is the science of applying the laws of mechanics to locomotor systems or biological systems. It is different from simple mechanics, because here we are talking of living beings and we also have to consider how to apply these laws through their psycho-emotional and mental systems. The next question to consider will be how do these systems interact? Do they interfere or coincide with mechanics? From this perspective the application of laws of mechanics to human beings is not so simple.

The scientific data and experience known to us say that treadmill running is easier then overground running. "It has generally been found that overground running does incur greater metabolic costs compared to treadmill running, particularly at faster speeds of running. At the present time the extent that other differences in running mechanics between overground and treadmill running affect oxygen uptake is not known" (Biomechanics of Distance Running, 1990, Editor P.Cavanagh, Human Kinetics, p.276).

Obviously these facts are in favor of difference between these kinds of running. The more mechanical work is done, the more the energy costs: this is a simple equation. But still the "other differences in running mechanics… (are) not known".

If we do accept that mechanics is the science, where the force, work and energy are studied in their application to various objects, then in biomechanics, the main thing is how it all applies to a living object. So to consider the differences between treadmill and overground running, we need to answer the following questions. What is the difference in the use of forces involved in both kinds of running? How is gravity involved in both cases?

Running on the ground we have to release the force of gravity to start and continue the run. Running on the treadmill we have to wait for the belt movement, which also goes in the opposite direction from our body. This is already a big difference: what moves our body and what force is involved? Sure the ground reaction will be the same because the transmitter of gravity to the ground is the same, which is the body weight. But which force is working to change the support or to move the body weight from one leg to the other? In overground run it is gravity, on the treadmill it is the belt, moved by an electric engine.

The next thing to consider is the difference in muscle work in these two kinds of running.

On the treadmill, our main concern is to not release the upper body and keep the feet moving according to the moving belt. In the overground run we have to make sure that our feet catch the upper body moving (falling) forward, with no consideration to the ground, which is a quite different physiological and psychological task. So here the muscles are involved in two different logical sequences and hierarchical relationships in order to serve the main task: to catch the belt, in the first case, and to catch the body, in the second.

Consequently, all neuromuscular patterns are developed for these different goals: to serve the moving belt speed or the falling body velocity. It is the difference in operational systems. In the first case the main thing is the moving belt, and everything is lined up according to this main parameter. In the second case, the main parameter is the falling body, and everything is done to serve the purpose of its proper movement. An also, in the first case, we are controlling the feet movement according to the moving belt. In the second case, we are controlling the feet position according to the falling body.

So, though the forces are the same, their involvement is different. Coordination wise, serving the body falling is a much more sophisticated process in terms of time and space, than serving the belt moving with the specific speed and body position fixed in the same space. From the emotional perspective, running on the belt is a much more predictable and less scary activity, than a "free" falling body movement.

The above-mentioned creates a "slight" difference in the whole perception of running: one with a required attention to the body position in relation to the feet (overground), and the other with attention to the feet in relation to the belt (treadmill). So, we have two different biomechanical systems of movement, which are not yet supported by the science of running, because the research is not done yet.

At the present time our discussion is not fruitful at all, and we spend too much time and energy without benefiting anyone. We are still at a guessing stage and operate with a very limited knowledge about the subject of discussion. We build our theories on pure theoretical assumptions that it could be this way or that way, and no one has any real data. We can share our understanding of this problem with support from known data and experience, but I do not see any benefits when we are crossing the borderlines of sharing to arguing. Then we have to ask ourselves, what is the goal of our discussion?

Dr. Romanov

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I think perception is misleading, if you could expand the size of the belt in all directions so you couldn' run off it in any direction and kept the belt velocity constant, without visual clues of a stationary objects off the belt you would not even be aware you were in motion and your running speed and effort would be the same in all directions in relationship to the belt.

Posted by: tlarson at October 16, 2006 09:24 PM

I would think it would be easy enough to compare running on a treadmil with on the ground - do a speed test. Go for a personal record on a treadmill for say 5 miles and do the same thing on pavement. See how your times compare. If running on a treadmill is much easier, I would think you'd have a much better time - no?

Posted by: troy at August 24, 2006 09:56 PM

Of course Pieter is right from a physics point of view. Running on a treadmill it is the same thing as running in a riding train. From a mechanical point of view there are two speed vectors in both cases. However this notion is as relevant for running as the colour of your grandfather's hair

From a biomechanical point of view, both cases cannot be compared since jumping on or off a riding train usually doesn't happen, treadmills come in limited sizes and you don''t have to push the ON button on Earth.

Posted by: ruben at January 17, 2006 04:51 PM

Has anyone addressed acceleration via * falling * in this treadmill / earth discussion?

Running on the * big enough treadmill * or moving sidewalk, at an airport in either directioin is not materially different than running on stationary ground — 'cuz you're moving forward as you run. Falling.

What about the * log rolling * lumberjacks do for entertainment? How, aside from pressing the start button, and the consequences of tripping is a treadmill different from that?

How might falling differ in treadmill running versus asphalt running?

Posted by: christopher drozd at December 10, 2005 09:53 PM

Hello everybody

I have an ongoing argument with my father on that subject. He claims that it's easier to run on the treadmill because of the belt's movement, but having learned physics in high school I obviously disagree (as was explained here before)...

Dr. R, you said:

-- Pieter, did you try run on a moving belt in a same with the belt and then in an opposite direction? If your running is the same, then I have nothing to say! --

So about that: have you ever stood on a conveyor belt (for example, in an airport) and then started walking on it? Was it any more difficult than walking overground? My answer to that is no, and that pretty much answers your question (the one that I quoted) and refutes the argument that the moving belt helps u run.

I do agree though with the 2 arguments that M gave, and would like to add the minor yet not neglectable air friction factor.

To explain M's second argumet: we all agree that the fact that the belt has to accelerate in the start of the run helps us to start running. Each time we land on the belt we slow it down a little (no argument about that), so in the same exact way as before the first step, the belt has to accelerate again, which helps us with the following stride.

Apart for these 3 factors (the treadmill's springiness, the belt's slowing down with each stride, and air friction) I really can't agree with any other argument that was given here.

Please say what u think, also considering what I say about the conveyor belt in the airport.

Regards,

Oded

Posted by: Oded at October 16, 2005 10:06 PM

Dr. R has stated and I quote:

"Is treadmill running the same as a ground running? It's not. And at first because you can't use the gravity as a propulsive force frorward, because there is no forward movement."

Mmm, Clearly we are talking physics here!? Apart from the fact that you can not use the force of gravity as a nett propulsive force in running (might be another interesting discussion? ;-)) this is not correct because you have off course movement relative to the running belt. In the system of the moving belt gravity is also there. What then is the difference?

Other quote: "You should pull the support foot even faster then in outdoor running, because of the belt "helping" "

Is this from a biomechanical or mechanical viewpoint? And if it's the first one what does this tell me? Do I as a runner have the feeling that the belt is helping me????

And: ""The difference treadmill/ground running mostly not so much related with air resistance, as with the help of belt pushing us off the ground"
???

I have proposed gedanken (=mind, don't know if the term is known in english) experiments that make it very easy to discuss these things by bringing mechanics and biomechanics together on several occasions on which dr. R never has given a reaction. I'll quote myself:

"To be clear we are talking about the same thing: Do you agree that the following situations are the same from the viewpoint of the runner and that there is in theory no way that the runner can find out in which situation he is:

1 You are inside a caravan (no windows) which is pulled by a car. In the bottom of the caravan there is a hole. The ground is made of the same rubber as a treadmill and feels exactly the same. The cart is moving in a straight line at a constant speed and you jump in the hole and start running. You are forced to run at the same speed the cart is moving.

2 You are inside a caravan which is not moving. In the bottom of the caravan there is a hole. Inside the hole there is a moving treadmill. The moving treadmill moves at the same speed backwards as the caravan was moving forwards in situation 1 and looks and feels the same. You jump on the treadmill and start to run at the pace dictated by the treadmill.

3 Same as 2 but now with a moving caravan.
"

Very simple to give an answer to this or not? I am still very curious about the reaction and it would also put an end this discussion once and for all. Which might be a very good thing. ;-)

Pieter

Posted by: pieter at July 19, 2005 06:34 AM

Pieter, if I understand this issue correctly, you are stating your point continually from the physics point of view. This discussion, is from the biomechanics point of view. Not physics. So would you agree that we can close this subject? From the very begining as I'll quote Dr. Romanov stated above:

"I am trying to discuss the difference in BIOMECHANICS as opposed to physics, where we already agreed, we practically don't see any difference."

So after we've gone over this over a dozen times. What exactly is the direction of this discussion? Physics or Biomechanics? Let's clear that up before anything else.

Thanks,
Severin

Posted by: Severinka at July 18, 2005 04:37 PM

Dr R,

It's not possible because the belt is so small that's the only reason.

Let's do an experiment: you stand in a moving train (constant speed, straight track) with blinded windows. Can you find out in which direction the train is traveling? No! It doesn't matter if you run back to front or front to back or in the sideways direction for that matter (yes that's not possible because you will hit the wall but if the train was wide enough...) And now: what is the difference between running in a moving train or running on a moving belt: none!

Sorry, I am really not trying to be annoying here. This is just simple physics.

Posted by: pieter at July 18, 2005 01:31 PM

Pieter, did you try run on a moving belt in a same with the belt and then in an opposite direction? If your running is the same, then I have nothing to say!
Dr.Romanov

Posted by: Dr.Romanov at July 15, 2005 12:20 AM

Yes I like to argue (in a friendly way I hope :))

In my book the theory of relativity has to do with clocks running at different speeds, contraction of lenght and changing mass etc. in systems that move very fast relative to eachother. At slower speeds these effects become so small you will never notice them.

Dr. R.

You say: "Your imagination about the Earth as a big running belt is a bit exaggerated. The Earth is moving (rotating) in one direction, and you actually never feel it, but we can run overground with the same speed in any direction (East, West, North, South), because the relative speed of our running (even in sprinting) is not effected by the rotation of the Earth"

Yes, the effect of the rotation can be neglected. Then the two situations are very comparable!?: on a running belt it doesn't matter also in what direction you run, the only problem is the small size of the belt. If the belt would be large enough: it is the same

As I understand it you say: mechanical the two situations are completely equal but the Biomechanics (how the body works as a whole) is different because the runner percieves the situations to be to be different. If you make the situation the same biomechanically: for example: block out the sideview while running overground. On the treadmill: show a movie to the runner while he is on the treadmill of what he would see when running (outside) overground. In this situation the biomechanics would be the same also.

This is off course only for the sake of argument because in reality it would be very hard, if not impossible, to make the two situations biomechanically the same.

Kind regards,

Posted by: Pieter at July 5, 2005 05:32 AM

Pieter,
Your imagination about the Earth as a big running belt is a bit exaggerated. The Earth is moving (rotating) in one direction, and you actually never feel it, but we can run overground with the same speed in any direction (East, West, North, South), because the relative speed of our running (even in sprinting) is not effected by the rotation of the Earth.
I am trying to discuss the difference in BIOMECHANICS as opposed to physics, where we already agreed, we practically don't see any difference.
I would like to make a point that Biomechanics is a separate science, which has its own rules and principles. Let’s face it; what you say in physics is theoretically correct. But theory isn’t always fact. When used in the real world, obvious problems arise, and unless you train in a perfect theoretical world, then I would not recommend training on a treadmill whenever possible because your success on a treadmill doesn’t necessarily correlate to good race times. Does this make more sense? Please stick to biomechanics, not physics.
My best regards,
Dr.Romanov

Posted by: DrRomanov at June 30, 2005 02:43 PM

Pieter,

I'm sorry but I lost you there my friend... what exactly is the point of this discussion? What exactly are you trying to get out of talking about jumping out of the moving car? What does that have to do with running?

And yes Relativity Theory has everything to do with this discussion. At least now I understand what and why you don't understand.

Catherine link-arseneau,

There is NO PUSH OFF with toes in Pose Method at any time, EVER.

There is no landing flat footed either or landing on the heel.

Please visit the Pose Method section to find out what Pose Method is.

Posted by: Lana at June 30, 2005 09:28 AM

is it better to hit the ground with a flat foot and then push with the toes when running or hit the ground with the heal and then push with the toes?

Posted by: catherine link-arseneau at June 30, 2005 08:31 AM

I know that a running belt is far from perfect. I actually only ran on one once: hated it btw. This slowing down of the belt can be used to perfect your technique. I also had this idea to build a shoe that actually measures the speed of the ground relative to the shoe just before impact. If you couple something audiable to it you essentially have the same feedback.

Lana,

I think it's not pointless to cut a discussion in pieces. If one can not agree on the foundation of the discussion, the basic premisses then the rest is maybe quite pointless...I agree (like m also says) that starting to run on a treadmill is different from strting to run on the ground, but once the belt moves at a constant speed or if you start to run and you are already standing on the moving belt( example the earth again)...If you first press the button and let the belt reach it's speed and then jump on it it would be the exact same thing as jumping from a moving car or something and start to run. When you are on/in the moving car the ground moves relatively to you == when you stand next to a moving running belt the belt moves relative to you: same thing. When you jump from the car and keep running at the same speed the car does you keep up with the car and your movement relative to the car is zero: same with the running belt: you also don't move relative to the ground when you are on the moving belt.

The theory of relativity hasn't got anything to do with this discussion. ...

Posted by: Pieter at June 30, 2005 03:49 AM

I like what you said - 2) is easier to detect on a treadmill due to the sound of the machinery. This could offer positive feedback for improving style and reducing impact based braking, thus improving efficiency aswell.

Some people at my gym are just elephants :) and then they get off the treadmill limping...

Posted by: Lana at June 30, 2005 12:46 AM

What part of physics doesn't add up?

What exactly do you want to be admitted? That SOME components of physics of running on the ground and on the treadmill are the same, like gravity, time on support, body weight, ground reaction?

Nobody argued that.

But why are you talking about only a selected number of things when there is so much more involved?

When you talk about the difference between treadmill and overground running don't cut it in pieces because it doesn't work that way. Human beings are not emotionless pieces of clay and we don't live in a vacuum. You CANNOT DENY that. And that renders your argument pointless.

I keep rereading all your posts here and the forum and the first question I want to always ask you is : do you ever push the "ON" button on the treadmill?

Two questions for you and let's drop the theory for right now:
1. Does the belt move under you on it's own?
2. Does the ground move under you on it's own?

And don't tell me that the mother Earth rotates, because it doesn't, not in a sense that would affect your running.

Stand still and look down at the ground - does it move? If it does then your head is spinning.

Now stand on the treadmill, does the belt move? No. Now push the "ON" button, does it move now? Yes it does, and you're forced to start moving your feet.

Besides everything else, that moving belt creates the difference in the running technique when running on the treadmill compare to running on the ground.

Do you know anything about Relativity Theory? You should find out what it's about because it applies here.

Posted by: Lana at June 30, 2005 12:40 AM

I agree totally that the physics of running on a treadmill (apart from the start), and hence the actions of gravity, support, forward motion etc. are the same as running on the road. To talk about differences in mechanics when the belt moves relative to the still runner compared to a runner moving relative to the still ground is nonsense.

However, there are some small differences between real treadmills and the ideal treadmill – other than the obvious one of perception – which may affect the running style and efficiency.

In my (limited) experience of running on a treadmill I have noticed the following:

1) Treadmills have a springy surface. This could aid with the rebound from the ground and help increase the proportion of energy derived from elastic stored energy rather than from muscular work. This could also explain why runners land with a flatter foot on a treadmill as the surface is more compliant than roads.

2) When I run, I have a tendency to land on the heel (I’m new to Pose), this accentuates the difference between the earth and a treadmill. When I hit the treadmill, the belt hesitates and although my body is forced backward slightly, the compliance of the belt reduces this. When I hit the ground it does not change velocity relative to my body, and I therefore decelerate more than I would on the treadmill. I’m not sure whether this change in belt velocity is noticed by the speed/distance counter on the treadmill, it is certainly noticed by me slowing slightly when running outside and my muscles probably have to work harder to absorb this shock. I would not be surprised if this same effect occurs in all running styles although obviously to a much smaller extent if you don’t overreach.

I would also guess that the effect described in 2) is easier to detect on a treadmill due to the sound of the machinery. This could offer positive feedback for improving style and reducing impact based braking, thus improving efficiency aswell.

Posted by: m at June 29, 2005 11:00 AM

Dr. R

I am very sorry but the physics you describe (still) don't add up. That's also my only point against. I agree totally that the experience of running on a treadmill is completely different from the psychological point of view. And that's immediatly the only difference. If you close your eyes you could not even notice the difference (in the case of a perfect running belt and a nice breeze made with a windmachine that doesn't make a sound etc...).

This is not correct. The earth is also a very large treadmill so the same argument can be used against. Imagine a very large running belt on the earth on which you are stationary and start to run: same thing as running on earth itself.

There is off course a big psychological difference: You are afraid to fall off! If running belts would be bigger this factor would be less of a problem. If you take a blind person and let them run on a belt or overground they would not know the difference.

Running on a belt is like running overground with a small electric fence around you which moves at a constant speed. You do everything to not touch it; like you do everything to not fall from the belt. The mechanics between these two cases are the same: If the fence was wide enough and the belt big enough you could close your eyes and again would not know the difference.

Like the two other comments also say: Running on a belt is very constant. It's like running with a pacemaker (rabbit in english?) and you can run better times. The second factor is no friction with the air.

I think it's just the opposite. It is more predictable in the sense that you know the pace you have to run but you are at the same time afraid to fall off. I think I read somewhere that you lengthen the time on support (because of the fear off falling). You look for ways to feel more secure.

I don't know if this discussion is fruitfull or not. In the end I just hope you admit that apart from psychological factors and the absence of friction with the air the two cases are in essence the same.

Posted by: Pieter at June 29, 2005 09:31 AM

By my experience running with treadmill can be helpful for teaching efficiency. It could be similar to dr. Romanov "Do nothing" princip.
On treadmill you choose one speed (say 15km/h) and you must just stay on the treadmill. You must just lift your legs quickly enough to match the speed of the treadmill. LoMGuy is right: On treadmill we have always good cadence and maybe efficiency from that. One of my cues when running overground is : I think that I'm running on treadmill and then just lift my legs enough to match the speed. Such thinking has helped me to break 34min for 10K. Don't know if it will work for others but for me was very helpful.
Sorry for bad english.
Miran

Posted by: triman at June 29, 2005 01:15 AM

If we keep coming back to the same issues is not a fruitful discussion. Lets try something new.
Why is running on a treadmill easier?
It appears speed is more constant on a treadmill.
It appears running at a more constant speed is more efficient.
Is stride frequency (cadence) higher on a treadmill? That would explain the difference in efficiency and the use of gravity.
It seems that running efficiently is easier on a treadmill. Could we use this aspect of running on a treadmill to our benefit or does it only apply to running on a treadmill?

Posted by: LoMGuy at June 28, 2005 03:40 PM