1% Grade on Treadmill = Outdoor Running
 

Some chatter on the board about this. Thought I would post some research. Having run quite a bit on the road and treadmill, this fits with what I have anecdotally found. See study below:

J Sports Sci. 1996 Aug;14(4):321-7.

A 1% treadmill grade most accurately reflects the energetic cost of outdoor
running.

Jones AM, Doust JH.

Chelsea School Research Centre, University of Brighton, Eastbourne, UK.

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've heard 3% before....but then again I hate jogging.

% grade
 

Not too much difference between 3% and 1% really. Just that 1% more closely matches running outdoors on a flat surface. 3% would not be that far off. Of course, when these studies are done, the % grade on the treadmill is always calibrated. You can't always count on the read out on the machine to be accurate.

Oh...I love running but I hate running on the treadmill, no matter what % grade!

Mike

Im with ya.

I tend to keep it within 1 mile, 1.5 at the most, at an increasing intensity. I dont think you can ever really match outdoor running with a treadmill, no mater the grade.

Treadmills pull your feet back for ya, and they run continuously underneither you. When im slowin down after a sprint, I do a couple bounds as it slows down and it just spins under me without me really doing anything other than jumping. Cant do that outside.

Not to mention, its rather linear in direction.

Outdoor running on a not overly improved trail is real running. Running on a treadmill is a boring waste of time. Running on the cement or tarmac bike trail around the park is almost as bad.

Run on the turf at least! Or pick a steep enough grade that you don't even NEED to run up because just walking up it will make you pant!! Hiking a mountain is real world fitness... and it's pretty... and it's relaxing...

Running on a treadmill is boring torture. Get outside and get some Vitamin D and a life! :D

It depends on the speed and the treadmill. The biggest difference is lack of air resistance on the treadmill. As speed increases, the wind resistance increases. In the study above, slow speeds (about 6-7 MPH) corresponded to a 0-1 degree incline while the faster speeds (about 9- 11 MPH) corresponded to a 1-2 degree incline.

This doesn't mean that you should run on a treadmill at 1 degree incline all the time. The goal isn't to obtain the same energetic cost. Some variety is good.

Walking up a steep incline isn't all that similar to running. Actually, in a lot of ways it's more similar to biking.

No its not. Not with cleats at least. In that case, you engage you hamstrings on the up stroke, not similar to any form of running, cept maybe backwards up a hill.

Ive noticed increases in foot speed from hill training, maybe its more similar to agility work.

When I do use the treadmill though, I use it to do things I cant on land. Like, run at 16 on an extended decline. Save your run training for functional run training. And save your knees and hips, run outside on trails.

Well, running has a strong eccentric component for both the quads and calves. Walking up a steep hill and biking don't.

In running a significant amount of energy (up to 50% of total energy in some estimates) is stored in the achilles tendon, arch of the foot, and some other structures. It's much less in uphill walking and less still in biking.

Running has a short explosive foot strike. Walking uphill and biking have a long continuous force production.

Running uses no knee extension. Walking uphill uses some and biking uses a lot.

So in a number of ways it's closer to biking but definitely quite different from both.

I agree that hill running can be great for running as long as it still resembles running. I also try to use the treadmill for things I can't easily do outside. You have a treadmill that allows a 16 degree decline? The ones at my gym go to 5 at most.

Theoretically, form for hill sprints is supposed to be exactly the same as sprinting on flat ground. Meaning they should be working the muscles the same except one is harder since you're going uphill. If you're leaning significantly forward in your hill sprints you're doing it wrong.

Right. Most efficient for hill running is shorter faster steps, as compared to trying to increase stride. This would be like gearing down on a bike, using quick leg speed to compensate for the incline.

You should be running with your eyes lookin up hill and in an upright position.

But yeah, even my mom's cheap one goes up to 12 on incline. There are two at one of the gyms I go to that goes up to +20 and -4 and has a max speed of 20. Ive only seen a couple people run at 20, and that was with a belt that lifts suspends your body a little over the treadmill so you have less weight pushing down. Its suppose to help with allowing the body to run at higher speeds easier.

And I dont think they are degree inclines, they are measured in % I believe.