Is outdoor running > treadmill running?

Oisin11178

I know most people will say outdoors is better but there is a reason for this question.
If you can achive say 10k in under 40 mins on a treadmill at about 90% is it reasonable to assume you would go under 40 mins outdoors during a race?
Assumimg that the course is reasonably flat and the wind is negligable.

Oisin11178

Can one of the mods move this to the main section please.

tunney

Oisin11178 wrote: »

I know most people will say outdoors is better but there is a reason for this question.
If you can achive say 10k in under 40 mins on a treadmill at about 90% is it reasonable to assume you would go under 40 mins outdoors during a race?
Assumimg that the course is reasonably flat and the wind is negligable.

You can cheat running on a threadmill. Vertical height translates to horizontal movement.

RoyMcC

Oisin11178 wrote: »

If you can achive say 10k in under 40 mins on a treadmill at about 90% is it reasonable to assume you would go under 40 mins outdoors during a race?

Hmm possibly, if the tready is at 2-3% incline. But even outdoors you'll always be sure to improve on your training times in a race - probably by 10% if you're a lazy trainer (like me.)

Oisin11178

Since i started running my treadmill times for distances like 5k and 10k have always been very close to race times. Maybe as someone already said the lack of external forces such as weather ect.. are negated by race day adrenaline and taper.

sean_84

tunney wrote: »

You can cheat running on a threadmill. Vertical height translates to horizontal movement.

I'm not sure about that. If you don't make horizontal movement relative to the belt, you'll be going off the end of the treadmill

bart simpson

sean_84 wrote: »

I'm not sure about that. If you don't make horizontal movement relative to the belt, you'll be going off the end of the treadmill

yeah, could you explain more on what you mean tunney,
if you were measuring a 10 k outdoor course and you did it 100 % accurate but all of it was up hill, the competitors would run 10 k, but if the crow flew it it would not be 10k....so the threadmill is the same as outdoor when it comes to factoring inclination and distance, isnt it?

BeepBeep67

If you take long loopy strides on the treadmill, the belt is still moving at 16 kmph and you can run at the same speed with a lower cadence and use less energy. You can't do that outdoors as once you're airbourne you're slowing down.
Personally I find sessions on the treadmill harder than the track, but I think that is just mentally.

Andrew Hoey

doesnt the treadmill sort of carry ur foot back so its not like a full stride

ThisRegard

To me it seems you're just lifting your legs on a treadmill, or very little energy to get some sort of forward momentum.

Whereas on the road you'll use a lot more energy to propel your body forward.

robinph

If you've only done your training on a treadmill then go and race on the road I'd not be surprised if you got injured. Your feet won't be used to the harder surface of the road and also roads are not flat, so the uneven surface will most likely cause you a mischief as well.

littlebug

I'm at the slower end of the running scale anyway but I do a fair bit of running on the treadmill. I haven't even come close to being as fast on the road as I am on the treadmill.... there's maybe 2 minutes difference between my fastest treadmill 5k and road 5k.
My heartrate stays much lower on the treadmill too, despite sweating twice as much and feeling like its 10 times harder.

Aimman

I've always found less effort in running on a treadmill. I remember years ago (long time ago) I was working out in a gym on a program and delighted with my running on a treadmill. after a few weeks, I went to the local park for a run and it near killed me.

You have to push yourself forward on the road, on a treadmill, you just have to get your foot in front of you in time, to hit the belt which drives your foot back.

If you think of the physics of it, and the conservation of energy and laws of opposite and equal reactions etc, the road does nothing, you do all the work. On a treadmill, when the belt is providing energy moving for you, then it means you have to apply less energy to do the same work.

Newton would have loved a treadmill, he'd have been indoors more and probably wouldn't be out and about when that apple fell.

robinph

He'd have fallen off the back of the treadmill at some point though so would probably have discovered gravity that way. Just as long as there wasn't any other dangerous gym equipment nearby that might have injured him more badly of course.

plodder

You're not exercising your glutes at all on the treadie. Also, the incline is a bit of a con. You're not actually working against gravity, just forcing your feet to work at an odd angle.

sean_84

I think there's some misconceptions about running on treadmills. The mechanics and physics of running on a treadmill are the same as running on a road. When your foot is on the road, it is trying to push the road down and back, and the road is pushing you up and forward. It is the same on a treadmill except now the forward and back forces are relative to the belt.

Reasons why you might get better times on a treadmill are:

• no wind resistance (but this isn't a huge factor at ~12km/h)
• a perfectly even surface
• a controlled constant pace
• inaccurate speed measurement by the treadmill

robinph

Admittedly it wouldn't work at running speed on a treadmill without a bit of effort to keep you stationary, but just hop up and down and you'll still be covering distance on it. Hop up and down on the road and you'll just stay where you are. On a treadmill the time spent in the air is just as useful for covering distance as the actual forward forces as the ground will still be moving beneath you. If you do big bounding strides on the road you'll be going nowhere slowly.

ecoli

sean_84 wrote: »

I think there's some misconceptions about running on treadmills. The mechanics and physics of running on a treadmill are the same as running on a road. When your foot is on the road, it is trying to push the road down and back, and the road is pushing you up and forward. It is the same on a treadmill except now the forward and back forces are relative to the belt.

I agree that the mechanics are essentially the same your foot is brought in under your hips and is connecting with the ground allowing you to generate maximum power in order to propel yourself in an upward and forward motion.

I think that the difference with a treadmill is the fact you are not generating this power but in fact once your leg hits the ground it is automatically being brought under your hips by the conveyor motion of the belt so you are effectively not using the same amount of energy to hold your running form as you would on the roads. As such there is less of an energy expenditure when you are tired on a treadmill and ultimately as your run progresses you are not suffering as much as you would in the outdoors.

sean_84

robinph wrote: »

Admittedly it wouldn't work at running speed on a treadmill without a bit of effort to keep you stationary, but just hop up and down and you'll still be covering distance on it. Hop up and down on the road and you'll just stay where you are. On a treadmill the time spent in the air is just as useful for covering distance as the actual forward forces as the ground will still be moving beneath you. If you do big bounding strides on the road you'll be going nowhere slowly.

If you just hop up and down you will go off the end of the treadmill
Imagine if you were on a train and you are hopping up and down. Would you fall off the end of the train or keep landing on the same spot?

sean_84

ecoli wrote: »

I think that the difference with a treadmill is the fact you are not generating this power but in fact once your leg hits the ground it is automatically being brought under your hips by the conveyor motion of the belt so you are effectively not using the same amount of energy to hold your running form as you would on the roads. As such there is less of an energy expenditure when you are tired on a treadmill and ultimately as your run progresses you are not suffering as much as you would in the outdoors.

But the road also brings your leg under your hips in the same way, as your body will have forward momentum. On both road or treadmill, if you stop running, your leg will go too far behind your body and you will fall on your face. When you actually want to stop running without falling, you will put your foot in front of your body so that the road will be pushing you back, causing you to lose momentum.

robinph

You'd still need some kind of forward movement to keep you stationary, but the higher you jump the more distance the treadmill will have moved underneath you for you only having used very little forward forces.

Emer911

Hate treadmills.
'nuff said!

robinph

Long article and I got bored long before the end:

http://www.pponline.co.uk/encyc/treadmill.html

...but it quotes a few studies about the difference between treadmills and real running.

plodder

I see people in the gym walking (actually hanging on for dear life) with the incline cranked up to the maximum. They should try running or walking up a real slope of 10-15% and they'd see the difference.

ecoli

sean_84 wrote: »

But the road also brings your leg under your hips in the same way, as your body will have forward momentum. On both road or treadmill, if you stop running, your leg will go too far behind your body and you will fall on your face. When you actually want to stop running without falling, you will put your foot in front of your body so that the road will be pushing you back, causing you to lose momentum.

Your leg may hit the ground similarly, however you do not take into account a the power you generate with the pull you exert on the ground plus stride length etc. The treadmill dictates your rhythm.

Here is an example

Athlete A (Road) exerts 80% effort to achieve a stride length of 1.75m in order to achieve 6 min

Athlete B (Treadmill) exerts 60% effort in order to maintain 1.25m in order to achieve the same pace

Here we see that the treadmill is compensating for the reduced effort and the stride length becomes insignificant

Interestingly here is a article on the matter

http://www.posetech.com/training/archives/000165.html

sean_84

Emer911 wrote: »

Hate treadmills.

Me too

robinph wrote: »

Long article and I got bored long before the end:

http://www.pponline.co.uk/encyc/treadmill.html

...but it quotes a few studies about the difference between treadmills and real running.

There's nothing there that contradicts what I am saying. I gave some points in my post above that can account for different performances on the road or the treadmill. Another two are that the surface is slightly soft/bouncy, and that the stride may change because of a fear of falling off the back. But the ideas that a treadmill is easier because it pulls your leg back or because it keeps moving when you are in the air are false.

ecoli wrote: »

Your leg may hit the ground similarly, however you do not take into account a the power you generate with the pull you exert on the ground plus stride length etc. The treadmill dictates your rhythm.

Here is an example

Athlete A (Road) exerts 80% effort to achieve a stride length of 1.75m in order to achieve 6 min

Athlete B (Treadmill) exerts 60% effort in order to maintain 1.25m in order to achieve the same pace

Here we see that the treadmill is compensating for the reduced effort and the stride length becomes insignificant

Interestingly here is a article on the matter

http://www.posetech.com/training/archives/000165.html

If Athlete B is only covering 1.25m/stride at the same stride rate, then he is moving slower.

Imagine a treadmill set to 12km/hr that is on wheels and is being pulled forward by a car at 12km/hr. The top of the belt will be static relative to the the road below, so you can see that is the same as running on the road.

MrCreosote

What about if you've a plane on the treadmill- will the plane take off?

ThisRegard

sean_84 wrote: »

Imagine if you were on a train and you are hopping up and down. Would you fall off the end of the train or keep landing on the same spot?

The physics is different, the train itself is moving and you with it giving you forward momentum, the treadmill is stationary.

Gringo78

I do about 50% of my running on a treadmill at the moment. I pay no heed to pace and just try to hit HRs that I know I would hit on the road at that pace. I use 1% incline and find big variation in speeds between different treadmills, but never really correlates to the road, could be faster could be slower. I can see though how you could develop a running style suited to higher speeds on the treadmill....eg you often see people grabbing the handles which definitely enables you to run 'faster' on the treadmill

plodder

sean_84 wrote: »

But the ideas that a treadmill is easier because it pulls your leg back or because it keeps moving when you are in the air are false.

What if the belt weren't motorised? Would that be harder or easier, or the same?

sean_84

MrCreosote wrote: »

What about if you've a plane on the treadmill- will the plane take off?

Yep, because the force causing acceleration is provided from the jet engine or propeller, and not the wheels, so it will move forward relative to the air around it regardless of what the treadmill underneath it is doing.

ThisRegard wrote: »

The physics is different, the train itself is moving and you with it giving you forward momentum, the treadmill is stationary.

Yes, but I was trying to explain that you will land on the same spot relative to the the body you are hopping up and down on, and not the earth beneath.

plodder wrote: »

What if the belt weren't motorised? Would that be harder or easier, or the same?

Harder, because you have to overcome the friction between the belt and whatever pulleys it is running on. Acceleration will be harder again, as you will also have to accelerate the belt.

Anyway I'd say Gringo78's approach is good, and suggests that not much effort is put into calibrating treadmills.

MrCreosote

ThisRegard wrote: »

The physics is different, the train itself is moving and you with it giving you forward momentum, the treadmill is stationary.

The train is stationary, and you're jumping up and down on a stationary carriage. It's everything outside the train that's moving.

ThisRegard

sean_84 wrote: »

Harder, because you have to overcome the friction between the belt and whatever pulleys it is running on. Acceleration will be harder again, as you will also have to accelerate the belt.

Therefore it's harder on the road due to friction required to get forward momentum, none if required on a treadmill. This is a job for Mythbusters.

bart simpson

robinph wrote: »

You'd still need some kind of forward movement to keep you stationary, but the higher you jump the more distance the treadmill will have moved underneath you for you only having used very little forward forces.

the same can be said for ground running, the higher you jump(longer stride) the more ground you will cover, when running over ground and you are in mid-air you are still moving forward (so is a threadmill).

but i would disagree with sean on the foot contact, longer foot contact is made with the threadmill than ground

robinph

I believe that Vinny Jones holds the world record* for the longest golf putt. Probably something along the lines of several miles as he did it whilst aboard Concorde and the distance was calculated as the ground covered. I suspect there was very minimal effort needed to actually push the ball that far forward as the plane was providing most of the effort for him.

Terry Wogan has the record for the longest putt actually on a golf course.

* Might be unoffical.

ecoli

sean_84 wrote: »

If Athlete B is only covering 1.25m/stride at the same stride rate, then he is moving slower.

Imagine a treadmill set to 12km/hr that is on wheels and is being pulled forward by a car at 12km/hr. The top of the belt will be static relative to the the road below, so you can see that is the same as running on the road.

I think you are missing the point here. The stride length becomes arbitrary on the treadmill because it is set to a certain speed so therefore dictated by the treadmill not the runner they no longer have to generate as much power from their push off as possible but rather put as little effort into staying on the treadmill as possible. The upper body comes into effect here as a person must use the upper body to help generate power through the swinging motion of the arms. On the treadmill this becomes less important as you are no longer trying to propel yourself as far forward in order to cover as much ground as possible

RayCun

Airplane on a treadmill

sean_84 wrote: »

Yep, because the force causing acceleration is provided from the jet engine or propeller, and not the wheels, so it will move forward relative to the air around it regardless of what the treadmill underneath it is doing.

No, it won't. If you're doing 25 mph on a bike on the road, you will feel a lot of wind. If you're doing 25 mph on an exercise bike in a gym, you won't.

In practice it would be impossible to balance the forward thrust and the treadmill speed, but if you could, the plane would be stationary relative to the air, so there'd be no lift.

bart simpson

robinph wrote: »

I believe that Vinny Jones holds the world record* for the longest golf putt. Probably something along the lines of several miles as he did it whilst aboard Concorde and the distance was calculated as the ground covered. I suspect there was very minimal effort needed to actually push the ball that far forward as the plane was providing most of the effort for him.

Terry Wogan has the record for the longest putt actually on a golf course.

* Might be unoffical.

and if vinnie played the putt back down the aile toward the tail of the concord...the ball would go in the opposite direction to the direction in which he played it! lol

ecoli

bart simpson wrote: »

the same can be said for ground running, the higher you jump(longer stride) the more ground you will cover, when running over ground and you are in mid-air you are still moving forward (so is a threadmill).

You also have to take into account power generated to ensure optimum forward momentum as well as height of the stride. I know a runner who has one of the most fluid strides i have ever seen however his times dont add up to the effort he puts into training simply because he gets great height with very little forward momentum in his running as such he is more bobbing along than running. However translate this to a treadmill and it would compensate for the lack forward momentum he would be unstoppable

bart simpson

ecoli wrote: »

You also have to take into account power generated to ensure optimum forward momentum as well as height of the stride. I know a runner who has one of the most fluid strides i have ever seen however his times dont add up to the effort he puts into training simply because he gets great height with very little forward momentum in his running as such he is more bobbing along than running. However translate this to a treadmill and it would compensate for the lack forward momentum he would be unstoppable

yeah i get what you are saying alright.
but if i was to hop up and down on a threadmill in a purely vertical motion, i would be brought to the back of the threadmill and would fall off and get busted wouldnt i?, now if i hopped using a slightly forward motion i would still be moving toward the back of the threadmill only slower. so if your friend wanted to maintain a static position on the threadmill he must maintain forward propulsion, well that just how i understand it but i could be wrong, might try it out in the gym, but better wait till after the marathon...dont need thread burn all over my face on monday

ecoli

bart simpson wrote: »

yeah i get what you are saying alright.
but if i was to hop up and down on a threadmill in a purely vertical motion, i would be brought to the back of the threadmill and would fall off and get busted wouldnt i?, now if i hopped using a slightly forward motion i would still be moving toward the back of the threadmill only slower. so if your friend wanted to maintain a static position on the threadmill he must maintain forward propulsion, well that just how i understand it but i could be wrong, might try it out in the gym, but better wait till after the marathon...dont need thread burn all over my face on monday

Your right and i agree but the effort needed in forward propulsion would be alot less to achieve the kinds of paces they lack in the outdoor if you get me?

sean_84

ThisRegard wrote: »

Therefore it's harder on the road due to friction required to get forward momentum, none if required on a treadmill. This is a job for Mythbusters.

This is friction between your foot and the road. On a treadmill there will be equivalent friction between your foot and the belt.

ecoli wrote: »

I think you are missing the point here. The stride length becomes arbitrary on the treadmill because it is set to a certain speed so therefore dictated by the treadmill not the runner they no longer have to generate as much power from their push off as possible but rather put as little effort into staying on the treadmill as possible. The upper body comes into effect here as a person must use the upper body to help generate power through the swinging motion of the arms. On the treadmill this becomes less important as you are no longer trying to propel yourself as far forward in order to cover as much ground as possible

I'm sorry, but this is wrong. The speed is dictated by the treadmill, but it is up to the runner to decide a combination of stride-length and stride-rate that will make up this speed. Try to think about the situation I described above about the treadmill being pulled along the road so that the top of the belt is stationary relative to the road.

RayCun wrote: »

No, it won't. If you're doing 25 mph on a bike on the road, you will feel a lot of wind. If you're doing 25 mph on an exercise bike in a gym, you won't.

In practice it would be impossible to balance the forward thrust and the treadmill speed, but if you could, the plane would be stationary relative to the air, so there'd be no lift.

The point is that the treadmill speed will have no impact on the plane's speed, as the plane's acceleration doesn't come from it's wheels. Planes can take off from water as well, and they don't do it by paddling really fast

RayCun

sean_84 wrote: »

The point is that the treadmill speed will have no impact on the plane's speed, as the plane's acceleration doesn't come from it's wheels.

But if there is an equal and opposite acceleration, then the net speed relative to the air is zero.
The direction of the acceleration provided by engines is straight ahead. The force lifting a plane comes from air moving at speed around the wings. If the air isn't moving at speed around the wings, there's no upwards force.

sean_84 wrote: »

Planes can take off from water as well, and they don't do it by paddling really fast

No, but they move fast relative to the surrounding air...

bart simpson

RayCun wrote: »

But if there is an equal and opposite acceleration, then the net speed relative to the air is zero.
The direction of the acceleration provided by engines is straight ahead. The force lifting a plane comes from air moving at speed around the wings. If the air isn't moving at speed around the wings, there's no upwards force.



No, but they move fast relative to the surrounding air...

if a plane was on a thread mill and reached full thrust it would not take off, but it would reach a speed on the threadmill speedometer to the speed of what it would in the air( excluding the wheel friction and more dense air at sea level)

what does take off got to do with it? the plane would still achieve speed against threadmill ,just would not be moving through air so could not take off.....if i didnt maintain forward porpulsion the threadmill would move it backwards....is this a taper madness thread

RayCun

bart simpson wrote: »

is this a taper madness thread

oooh yes

The important thing is not
"how fast are the plane's wheels moving on the surface of the treadmill"
which is very fast, but

"how fast is the air moving over the plane's wings"

If the engine is pushing it forward at 200mph, and the treadmill moving it back at 200mph, the wings aren't going anywhere. No movement in the air means no lift.


If you changed the experiment around, so that you had an airplane on a treadmill in a wind tunnel :rolleyes: and there was a giant fan blowing air at 200mph while the treadmill was moving forward, to keep the plane in the same place (but the engines were switched off... then you would have lift.
The plane would be lifted into the air, move backwards while in the air, and fall off the back of the treadmill.

Brianderunner

Lads there was a huge discussion about the plane taking off on a treadmill on letsrun a while back. They had pilots and physicists discussing it. They even made a mythbusters episode about it.

http://www.letsrun.com/forum/flat_read.php?thread=1161075&page=0

RayCun

There's even a web site
http://www.airplaneonatreadmill.com/

A) If the plane remains stationary relative to the ground, it will not take off.
If the plane moves relative to the ground, it will take off.

robinph

A stationary wing does not take off. If a plane is on a treadmill then it's wings are stationary to the air, therefore it does not take off. What the engine is doing is irrelevant as far as the lift is concerned.

sean_84

robinph wrote: »

A stationary wing does not take off. If a plane is on a treadmill then it's wings are stationary to the air, therefore it does not take off. What the engine is doing is irrelevant as far as the lift is concerned.

Why are its wings stationary relative to the air? The treadmill can be going backwards or forwards at any speed, and the plane can still take off (there might be some burning rubber though...).

Anyway the plane on a treadmill analogy isn't particularly relevant here. What is more relevant is a plane in a wind tunnel, which can fly but remain stationary compared to objects outside the wind tunnel!

By the way, in the mythbusters episode, the plane took off

sean_84

RayCun wrote: »

If the engine is pushing it forward at 200mph, and the treadmill moving it back at 200mph, the wings aren't going anywhere. No movement in the air means no lift.

If the engines are pushing it forward at 200mph, then the plane is moving at 200mph. The plane's wheels don't need any power going to them, they can be just free-wheeling, so the speed of the treadmill isn't relevant.

Another though-experiment:
Imagine you have a toy car with free-wheeling wheels and you are holding it on a moving treadmill. You will be able to move it forward (or backwards!) regardless of what speed the treadmill is moving at. It's the same for a propeller moving an airplane on a treadmill.

YFlyer

sean_84 wrote: »

By the way, in the mythbusters episode, the plane took off

No spoiler?