I'm amazed at how many people still think you can just jump up and down on a treadmill instead of running.

OP is correct. Don't bother debating with these idiots who think otherwise. It's obvious they've never taken a physics course after middle school.

* wrote:

Has anyone here ever actually run faster for any distance on a treadmill than on solid ground?

The treadmill is not as responsive as the tarmac or track so you will not run as fast. For instance my treadmill has springs in addition to the composite platform which flexes on impact. Two mechanisms to absorb impact. It is a very safe way to train.

I suspect those that feel a great difference from ground running vs. treadmill running are a degree fearful and/or uncoordinated resulting in a change in natural running mechanics. I recently tranisitioned from several months of ground running to the treadmill because of poor weather. I did not notice a bit of difference. The biggest issue with the transition is normally boredom, but that was not the case this year.

generalist wrote:

Clam Evans wrote:I disagree. If the treadmill is moving 1000mph and the plane is stationary (viewed from outside the treadmill), but the wind is blowing 200-600mph, the plane will still take off.

Except the treadmill speed is greater than the wind speed. You would need to reverse that. Also, in the real world friction would prevent flight. The jet would only fly in a vacuum.

If it did manage to take off, I'll bet it could fly to the moon if it was solar powered or some shit

I found this statement in a "For Beginners Only" column by a Susan Paul on RunnersWorld.com:

"To answer your questions, treadmill running and road running are not quite the same. Running on the treadmill is easier than running outdoors, for a variety of reasons. One reason is that the treadmill belt assists leg turnover, making it easier to run faster. So most runners find that their pace on the treadmill doesn’t correlate to their road pace. Also, some of the soft tissue conditioning or “hardening” that occurs with road running does not occur with treadmill running because the plate or base on the treadmill "gives" more than road surfaces. And, obviously there are no weather conditions to deal with when running indoors."

Wow! I think she is really saying the same thing as some of the posters on this thread! Shame on you, Runners World. (to give her credit, I guess the parts about a softer surface and weather conditions are correct)

I used to puzzle about this question a long time ago. I ound it helped to imagine a slightly fancier treadmill than your average gym club one. Imagine a treadmill that is moving along at a steady 8mph, that has a surface of ashphalt, or simulated grass, or whatever. Now imagine that it's a lot bigger than an ordinary treadmill - let's say a couple of miles in all directions. It even has trees and houses and stuff on it. The people who built went so far as to figure out a way to make the air above the treadmill move along in unison with the treadmill (except for minor, random disturbances that would just feel like breezes). Everything you could see would be mounted on the treadmill (except the clear blue sky). How would you know you were on a treadmill?

Well, you wouldn't. You wouldn't notice your foot getting dragged behind you slightly when you landed at the end of each step, you wouldn't be able to just kind of hop up and down and have the ground move under you - because those things don't happen on a treadmill.

link to RunnersWorld quote in above post:

http://www.runnersworld.com/beginners/how-effective-is-treadmill-running-compared-to-running-outside

Great post! That was the interesting thing about the show that the guy had taken many videos of runners and he said that ALL runners (sprinters to little old ladies) were .3 seconds between steps. I have not been able to find any other info confirming or denying this claim. That is why my original post.

Yes, here's a return from injury where I had to mix treadmill and road running. These were all from the same period.

Treadmill workouts:

5 mile tempo (26:34)

9 mile tempo (50:52)

6 mile tempo (32:33)

7 mile tempo (39:40)

Road:

4 mile tempo (21:15)

5 mile tempo (26:48)

7 mile tempo (40:30)

3k race (9:15)

Actually it's very questionable the way this is is presented. They say everyone spends the same amount of time in the air, then they say sprinters push their foot down harder so they are in the air longer. I think they're oversimplifying the "everyone spends the same amount of time in the air thing". .29 can be significantly different than .31

Shoes! wrote:

[quote]luv2run wrote:

But according a physicist friend of mine if you run on a treadmill then you do no work since you have not displaced yourself.

That is ridiculously stupid. The belt is going the opposite way, so to stay in the same place your displacement would equal the speed and length of the tread.

webfoot wrote:

your an idiot wrote:

No, it's not. On a treadmill you can spend more time in the air with a more vertical jump.

I'm truly amazed by the stupidity of letsrun posters.

No. You can spend more time in the air with a more vertical jump outdoors as well. Every runner has done this drill.

On the treadmill you can't simply jump vertically and expect to stay on the belt. This gets back to the original title of the thread. The moving treadmill belt will throw you off the back.

This is correct. It is very similar to running. The slight difference is the fact that on the treadmill the active landing of the foot is not as important for maintaining one's speed. On the other hand, a good recovery phase is very important, and in fact, this is the most important phase for a runner on treadmill or road.

i need to create a list of all the users who think there is a mechanical difference between running on a treadmill and outdoors, other than air resistance. That way we can be sure to avoid their opinions in the future and save time.

I did an hour on the treadmill today.

Set the pace at 8:27/mile (7.1 mph)

Started at .5% incline.

Every time a song ended on my ipod, I increased the incline another .5%.

From 35 minutes to 45 minutes I did not have to increase the incline because I was listening to the 10 minute live version of the Doors "Light my Fire"

The last few minutes I was running at 7.5% incline and it was kind of difficult. My elevation gain totaled 1,624 ft for the run.

It was 72° with approximately 75% humidity and I wrung my t-shirt out in the bathroom sink after I finished.

How would this compare to a moderately hilly run where I had to fight the ever present wind resistence at a breezy 60° and partly sunny?

Okay here is the list of people that don't get it. Please keep this list handy so you can save time replying to their posts in the future.

googlymoogly

your an idiot

NotAustin18

coach

Brian

worst poster

Treadmill runner

legsss

400metersoffseason

Duh.

I'll give luv2run the benefit of the doubt that he/she was joking.

Think about it hardloper. There is a motor on a treadmill using electricity and producing energy. The track pulls your leg back using electrical energy. The energy the body has is to get the foot back to its original position. On the road, your leg (not electricity) pushes the ground back propelling your body forward. Your leg still has to recover and get in position to push again.

Displacement is equal, but energy production is not quite equal. Since displacement is equal, energy should be equal, minus the electrical energy.

I got 68% in high school physics.

Easyloper wrote:

The track pulls your leg back using electrical energy.

That's not true. I run facing the back of the treadmill so the track is pulling my leg forward. I run so fast, the belt goes clear around keeping me on the treadmill instead of being tossed off the back.

Easyloper wrote:

Think about it hardloper. There is a motor on a treadmill using electricity and producing energy. The track pulls your leg back using electrical energy. The energy the body has is to get the foot back to its original position. On the road, your leg (not electricity) pushes the ground back propelling your body forward. Your leg still has to recover and get in position to push again.

Displacement is equal, but energy production is not quite equal. Since displacement is equal, energy should be equal, minus the electrical energy.

I got 68% in high school physics.

Great point, I get it now.

What grade did you get in Dutch? The opposite of hard isn't easy, it's langzaam, hoor.

I wondered about this a while back so me and my friends got some beers and did some calculations.

Air resistance causes approx 3% decrease in pace at 3min/km pace (no wind). That is 54 seconds on a 10k, not such a small difference. And the force induced by wind resistance increases quadratically, so if you have a wind 1x your pace in your face (V = 2x pace) you get 4x the resistance vs no wind, and arguably you get some wind at some point during every run.

Then there are some small differences in the forces at play when your foot strikes a treadmill vs the ground.

1. The treadmill has the capacity to do work on your foot. Think about a bounding heel striker here. When his foot strikes the treadmill it slightly decelerates the band and the motor reacts by upping the torque. We measured this current increase with a ammeter and it is not small, and for our biggest heal-striking dude the motor did a lot of extra work.

2. The key that we can take from (1) is that there is a deceleration occurring in the band. In the extreme case think of a treadmill with a very weak motor that stopped the instant your foot hit the band and continued at 3min/km pace while you were in the air. You can't really claim that you are running 3min/km pace. The reality is much more mild but small decelerations summed over a long run add up.

So of course we wanted to know, how much can you really cheat on a treadmill? Well, we got our beefcake heal striker to take advantage of the treadmill, and oh did he. We got him running 3min/km (max on this treadmill), the poor motor whining in pain every time his treetrunk of a leg slammed the belt. For me, at 140lbs, I felt like I could cheat a little bit (at the expense of my knees) but at 3min/km I still felt/looked like I was running hard.

So it would be neat to set up some sensors and actually measure this stuff, but why. I asked some elite marathoners about this and a few said running on a treadmill with a 1-2% incline roughly matches the effort of running outdoors, but they are still very different things.

Hardloper wrote:

Okay here is the list of people that don't get it. Please keep this list handy so you can save time replying to their posts in the future.

googlymoogly

your an idiot

NotAustin18

coach

Brian

worst poster

Treadmill runner

legsss

400metersoffseason

Duh.

I'll give luv2run the benefit of the doubt that he/she was joking.

Hardloper, I fully admitted to not being a physics expert. I even said maybe I'm wrong about this question. I took one basic high school physics class 20 years ago. After reading the responses, I'm fully ready to admit that your explanations, and those of others, make sense. I also admit to not really thinking this issue through before posting.

I also realize I'm wasting my time with this response, but some future advice might be to not be such an arrogant a$$ about your knowledge of a subject. If someone is off base on something and absolutely refuses to reason that is one thing, but when you belittle anyone that has a misunderstanding about a topic (on which it is clear many haven't fully thought it through) you just come off like an a$$. If I did that in every conversation I had with someone on a topic that I have more knowledge than they do, I'm not sure what the point would be.

That being said, kudos to you; I'll award you a physics gold star that you can put on your fridge to keep you feeling proud of yourself for your superiority. Good work to take the time to call out anyone that you were able to beat into submission with your physics knowledge.