Why are my treadmill times so slow relative to outdoors

Triathlon Forum
1

For whatever, reason, I find that when I run on the treadmill for the same effort as on “hard land”, I am moving around ~10% slower. It really does not matter which treadmill, I am just slower on the treadmill than at the track. I have not run much except on the treadmill all winter. I only started really shuffling/jogging/running after > 1 year break this winter. and almost all the running is on treadmill. I did a few outdoor runs, but with the recovery from a disk-nerve issue, the softer surface of the treadmill is easier on me.

In any case, the last two weekends, I headed to a local indoor track and was surprised by my times (not that they are that fast, but way faster than on the treadmill). For example, 120 seconds per 400m is 5 min per kilometer. That’s basically 7.5 mph. On the track this speed feels like jogging even with my limited strength/range of motion in my left leg.

On the treadmill 7.5 mph or 12 kph feels like a pretty decent clip. I would not be able to keep this up for a long time (like 20 minutes) on the treadmill. On the track, 96 second lap is 4 min per K pace or 9.3 mph/15 kph. This feels like a steady clip, nothing killer on the track but on the treadmill 9.3 mph/15 kph feeling quite hard. At this point, I have not gone that fast on the treadmill YET, but at at the track I was actually get a decent amount faster without trying “that hard” (my cardio is good for me from a lot of super hard swimming so I did not want to overdo it).

But this is not really new for me. 10 mph used to feel like a full out sprint on the treadmill. This is only 90 second per 400m which was not that hard in the past! 10 mph/16kph would literally feel like 80 second per 400m for me. I could barely stay on the treadmill for 80 seconds at that pace, but running on hard ground no problem basically going 80 second 400m pace which is 18 kph. Unless I am going pretty easy, the treadmill speeds vs “running on hard ground” really diverge.

I can only attribute this to a less “hard” push off on the treadmill since the belt is going at constant velocity under your body, but on hard ground you are doing a slight deceleration on landing and pre loading/compressing, allowing for a harder push off (unlike running like the road runner with the legs spinning like the road runner).

I remember Allan Faulds talking about doing some short treadmill intervals at 11-12 mph a few years ago and feeling totally off. 12 mph is 3 min per K pace.or 72 seconds per 400m. He said something along the lines of being able to run around that fast for 400m on the track, but unable to do that for the equivalent of a lap on the treadmill.

2

I have never had a single treadmill that has ever felt slow to outdoors. In fact the exact opposite is true. Every treadmill I have ever used feels effortless compared to outdoors. I don’t run these days at 0% so raising the incline levels it out, but at 0% the treadmill is supposed to be easier than outdoors.

3

I have never had a single treadmill that has ever felt slow to outdoors. In fact the exact opposite is true. Every treadmill I have ever used feels effortless compared to outdoors. I don’t run these days at 0% so raising the incline levels it out, but at 0% the treadmill is supposed to be easier than outdoors.

I wonder if it makes a diff if you are “pull” runner vs a “push” runner. If you get more of your speed from pulling with hamstring in the front vs pushing with glutes and quads.

4

Curiously - I kinda have it the same way. Though - I’m thinking it could be mental - cause my HR is roughly the same vs pace on treadmill as it is outdoors. Just that on the treadmill it feels harder.

5

its different for me on different treadmills. Outside on a LR i usually average around 7:15-7:25 a mile. The treadmill at the gym I frequent i can do the same distance on a .5% incline around 7:00-7:05 at the same effort. The treadmill i use at work i struggle to maintain a 7:40 pace.

6

its different for me on different treadmills. Outside on a LR i usually average around 7:15-7:25 a mile. The treadmill at the gym I frequent i can do the same distance on a .5% incline around 7:00-7:05 at the same effort. The treadmill i use at work i struggle to maintain a 7:40 pace.

Just to be clear, while I have minor variances between various treadmills, once the speed gets much beyond a shuffle into an actual run, my min/K is much better outdoors. And it’s not just a cooling thing due to airflow outdoors.

7

I have no real answer to this but I feel the same way. A tempo pace on the treadmill feels harder than outside but I just attribute that to being inside just like putting watts out on the trainer vs. outside. The treadmill I use most of the time is under a year old calibration is consistent so maybe it is just consistently wrong? Who knows but sorry I don’t have a scientific answer for you!

8

I have always had the same experience. Same speed on Treadmill as outdoors is MUCH more difficult for me to maintain

9

I have the same problem. I run on the treadmill about 70% of the time. I run at 0.5 incline @ 7.5 mph (8 min/mile) and my hr is typically high 140s/low 150s. Outside at the same effort and sometimes even an easier effort, I can run 30s faster per mile.

10

I have no real answer to this but I feel the same way. A tempo pace on the treadmill feels harder than outside but I just attribute that to being inside just like putting watts out on the trainer vs. outside. The treadmill I use most of the time is under a year old calibration is consistent so maybe it is just consistently wrong? Who knows but sorry I don’t have a scientific answer for you!

I’m in this camp. I find treadmill PE harder than outside, but my aerobic decoupling (for what it’s worth) is spot on on the treadmill. I’m assuming it mental/lack of external stimulus.

11

This is an easy one.
Treadmills hold speed pretty well.
Us humans unless you have run a fair bit on a treadmill don’t.
We are often longer with one stride or stronger in one leg and treadmills show up these imbalances due to the fact that on a treadmill our bodies are more or less stationary and we loose the smoothing effect of our own weight’s momentum.
Very symmetrical people struggle less.
Injured people like you exaggerate the problem due to the nature of your injury.

It’s the reverse of swimming in a plume where you can seem to get amazing glide out of your stroke as it takes a fair while for the moving water to begin to accelerate your body backwards.

12

I have always assumed TM runs are a bit more difficult because they absorb so much that you basically have to jump a little with each step as opposed to running on hard ground. I never run at 0%. I usually run at about 2-2.5% grade on a treadmill just to keep myself honest, but I always feel the TM run in my calves after.

13

This is an easy one.
Treadmills hold speed pretty well.
Us humans unless you have run a fair bit on a treadmill don’t.
We are often longer with one stride or stronger in one leg and treadmills show up these imbalances due to the fact that on a treadmill our bodies are more or less stationary and we loose the smoothing effect of our own weight’s momentum.
Very symmetrical people struggle less.
Injured people like you exaggerate the problem due to the nature of your injury.

It’s the reverse of swimming in a plume where you can seem to get amazing glide out of your stroke as it takes a fair while for the moving water to begin to accelerate your body backwards.

For the items in bold, I would tend to agree for sure on the second line. But before I was hurt and I would say I was quite symmetrical, I still felt at my higher end speeds there was a lot of discrepency. But generally what you are saying about the smoothing effect of our momentum makes a lot of sense. Maybe it’s like a low inertia training vs a high inertia trainer scenario.

14

I have never had a single treadmill that has ever felt slow to outdoors. In fact the exact opposite is true. Every treadmill I have ever used feels effortless compared to outdoors. I don’t run these days at 0% so raising the incline levels it out, but at 0% the treadmill is supposed to be easier than outdoors.

Research shows you need a 1% grade to = same cost as outdoor running.

15

I have never had a single treadmill that has ever felt slow to outdoors. In fact the exact opposite is true. Every treadmill I have ever used feels effortless compared to outdoors. I don’t run these days at 0% so raising the incline levels it out, but at 0% the treadmill is supposed to be easier than outdoors.

Research shows you need a 1% grade to = same cost as outdoor running.

That 1% grade is technically to overcome the effect of wind resistance, but this is incorrect the faster you go, in theory you need more incline to make up for the increase in wind resistance (it is dramatically higher at 20 kph vs 10 kph). But if anything the lack of wind resistance should make treadmill running faster at the same perceived exertion which is the case for Thomas, but not for several people who answered on this thread (taking out all the treadmill calibration stuff).

16

I’ve noticed quite a bit of difference in treadmills when you get up around 9+ mph. Here are some speculations:

  1. Sometimes treadmills are a little off speedwise. It may also slow down a little when a runner is on it.
  2. If the belt is a hair loose, it will slow down a little every step, making it harder to run. If it’s really loose, you’ll know it.
  3. Treadmills all bounce to some extent. This might help or hurt, depending on the bounce.
  4. Occasionally you’ll find a treadmill on a floor with an incline.
17

When I could still run fast, I really struggled to use treadmills.
I’m 192cm and my stride length usually meant that I could feel my shoes start to go around the roller on the rear of the mat if I moved even a tiny bit rearward of furthermost forward I could run on the treadmill without my shoes hitting the non moving frame.
I could not run faster than 20kmh on any treadmill I found, even though my 10km times just slipped under 30mins as my stride simply went too long to fit.
This is what made me sensitive to the pace variation thing I am talking about.
It was perfect form or fall off the back.

This having to keep perfect form made the treadmill feel harder than real running, but heartrates told a different story.
The faster I went on a treadmill the lower my heartrate compared to real running.
around 13/14kmh felt much the same as outdoor as my stride changed back to a jog and I had more room on the mat to vary my pace.

18

I’ve also never had a treadmill feel slower than the road. And I’ve used countless different treadmills, so it’s not just a calibration error.

This however seems to make sense to me (despite you having the opposite). Most TMs are shock-padded; I’ve seen some of the major manufacturers of midrange ones claim 15-25% impact reduction due to their cushioned decks, and that’s kind of what I feel on the TMs. As a result, I have to run with higher leg turnover (faster) to compensate for the lesser run impact compared to the road, and even so, the leg beatdown is not the equal to that of the road.

I actually use my TM a fair amount for recovery and injured-state running due to the softer deck, and it works great.

I’ve had friends who were fast as heck on the road but almost couldn’t even run at all on a TM - I think the mental bit is a big one, although coordination issues probably also come into play if you have a weird asymmetrical gait and can’t get into stride on a constant-speed treadmill.

19

I have never had a single treadmill that has ever felt slow to outdoors. In fact the exact opposite is true. Every treadmill I have ever used feels effortless compared to outdoors. I don’t run these days at 0% so raising the incline levels it out, but at 0% the treadmill is supposed to be easier than outdoors.

Research shows you need a 1% grade to = same cost as outdoor running.

That 1% grade is technically to overcome the effect of wind resistance, but this is incorrect the faster you go, in theory you need more incline to make up for the increase in wind resistance (it is dramatically higher at 20 kph vs 10 kph). But if anything the lack of wind resistance should make treadmill running faster at the same perceived exertion which is the case for Thomas, but not for several people who answered on this thread (taking out all the treadmill calibration stuff).

Well, I am not sure what you are saying but it is simple really. 1% grade = same energetic cost as running outdoors. See:

J Sports Sci. 1996 Aug;14(4):321-7.
A 1% treadmill grade most accurately reflects the energetic cost of outdoor running.
Jones AM1, Doust JH.
Author information
1Chelsea School Research Centre, University of Brighton, Eastbourne, UK.
Abstract
When running indoors on a treadmill, the lack of air resistance results in a lower energy cost compared with running outdoors at the same velocity. A slight incline of the treadmill gradient can be used to increase the energy cost in compensation. The aim of this study was to determine the treadmill gradient that most accurately reflects the energy cost of outdoor running. Nine trained male runners, thoroughly habituated to treadmill running, ran for 6 min at six different velocities (2.92, 3.33, 3.75, 4.17, 4.58 and 5.0 m s-1) with 6 min recovery between runs. This routine was repeated six times, five times on a treadmill set at different grades (0%, 0%, 1%, 2%, 3%) and once outdoors along a level road. Duplicate collections of expired air were taken during the final 2 min of each run to determine oxygen consumption. The repeatability of the methodology was confirmed by high correlations (r = 0.99) and non-significant differences between the duplicate expired air collections and between the repeated runs at 0% grade. The relationship between oxygen uptake (VO2) and velocity for each grade was highly linear (r > 0.99). At the two lowest velocities, VO2 during road running was not significantly different from treadmill running at 0% or 1% grade, but was significantly less than 2% and 3% grade. For 3.75 m s-1, the VO2 during road running was significantly different from treadmill running at 0%, 2% and 3% grades but not from 1% grade. For 4.17 and 4.58 m s-1, the VO2 during road running was not significantly different from that at 1% or 2% grade but was significantly greater than 0% grade and significantly less than 3% grade. At 5.0 m s-1, the VO2 for road running fell between the VO2 value for 1% and 2% grade treadmill running but was not significantly different from any of the treadmill grade conditions. This study demonstrates equality of the energetic cost of treadmill and outdoor running with the use of a 1% treadmill grade over a duration of approximately 5 min and at velocities between 2.92 and 5.0 m s-1.

20

I have never had a single treadmill that has ever felt slow to outdoors. In fact the exact opposite is true. Every treadmill I have ever used feels effortless compared to outdoors. I don’t run these days at 0% so raising the incline levels it out, but at 0% the treadmill is supposed to be easier than outdoors.

Research shows you need a 1% grade to = same cost as outdoor running.

That 1% grade is technically to overcome the effect of wind resistance, but this is incorrect the faster you go, in theory you need more incline to make up for the increase in wind resistance (it is dramatically higher at 20 kph vs 10 kph). But if anything the lack of wind resistance should make treadmill running faster at the same perceived exertion which is the case for Thomas, but not for several people who answered on this thread (taking out all the treadmill calibration stuff).

Well, I am not sure what you are saying but it is simple really. 1% grade = same energetic cost as running outdoors. See:

J Sports Sci. 1996 Aug;14(4):321-7.
A 1% treadmill grade most accurately reflects the energetic cost of outdoor running.
Jones AM1, Doust JH.
Author information
1Chelsea School Research Centre, University of Brighton, Eastbourne, UK.
Abstract
When running indoors on a treadmill, the lack of air resistance results in a lower energy cost compared with running outdoors at the same velocity. A slight incline of the treadmill gradient can be used to increase the energy cost in compensation. The aim of this study was to determine the treadmill gradient that most accurately reflects the energy cost of outdoor running. Nine trained male runners, thoroughly habituated to treadmill running, ran for 6 min at six different velocities (2.92, 3.33, 3.75, 4.17, 4.58 and 5.0 m s-1) with 6 min recovery between runs. This routine was repeated six times, five times on a treadmill set at different grades (0%, 0%, 1%, 2%, 3%) and once outdoors along a level road. Duplicate collections of expired air were taken during the final 2 min of each run to determine oxygen consumption. The repeatability of the methodology was confirmed by high correlations (r = 0.99) and non-significant differences between the duplicate expired air collections and between the repeated runs at 0% grade. The relationship between oxygen uptake (VO2) and velocity for each grade was highly linear (r > 0.99). At the two lowest velocities, VO2 during road running was not significantly different from treadmill running at 0% or 1% grade, but was significantly less than 2% and 3% grade. For 3.75 m s-1, the VO2 during road running was significantly different from treadmill running at 0%, 2% and 3% grades but not from 1% grade. For 4.17 and 4.58 m s-1, the VO2 during road running was not significantly different from that at 1% or 2% grade but was significantly greater than 0% grade and significantly less than 3% grade. At 5.0 m s-1, the VO2 for road running fell between the VO2 value for 1% and 2% grade treadmill running but was not significantly different from any of the treadmill grade conditions. This study demonstrates equality of the energetic cost of treadmill and outdoor running with the use of a 1% treadmill grade over a duration of approximately 5 min and at velocities between 2.92 and 5.0 m s-1.

I am going to disagree with this study because it defies physics/math. It makes no sense that the wind resistance at 3.75 m/s is the same as 5 m/s. It’s simply that their study was not precise enough. 5 meters per second is 18 kph. 3.75 m/s is 13.5 kph.

Wind resistance (the wind retarding Force you are exposed to at any moment) is proportional to the square of the velocity of the moving object, so your power is proportional to the cube of the velocity. Power = Force x Velocity (and above I just explained that in this case, force has velocity built in, thus power is proportional to the cube)

Whereas, as you speed up at 1% grade the additional workload (rate of climb) is proportional to the the sine of the angle of climb (close to 1 degree at one percent, not exactly though). The power should be velocity multiplied by the weight of the runner mutiplied by gravity multiplied by the sine of 1 degree. As you can see this number is only linearly proportional to velocity as all the other numbers (mass, gravity, sin theta) are all constants. So basically math says these guys who designed this study were not measuring with sufficient precision. I am actually surprised it passed a peer review. There are many other aspects that could have come into play on oxygen uptake, it still does not mean that a constant incline covers the additional wind resistance at all speeds.

At the really low speeds, zero percent is probably closer, intermediate speeds maybe 1 percent, high speeds, could be a bit higher. They probably needed a treadmill that could be set at 1/10th of a percent too like on a Woodway to get properly precise.