Treadmills and elevation gain

This guide will help you measure the incline of your treadmill, and applies to any treadmill, not just NoblePro treadmills.

Before we get started, there are a few things to cover around how incline in measured. After covering this, we’ll explain how to measure your treadmill incline. If you want to skip ahead, click here.

These are the topics we’ll cover:

1. Treadmill incline can be measured in a few different ways.
2. Incline should be measured relative to the floor, and not the treadmill frame.
3. How to measure your treadmill incline.

Different incline measurements

There are 3 different ways in which treadmill incline is measured:

1. “Levels” or “steps” (which is usually just a number)
2. Percentage (%)
3. Degrees (°)

Levels

“Levels” or “steps” (we’ll use “levels” from here on out) are an arbitrary number of stops between the minimum incline and the maximum incline of a treadmill. Usualy, when the treadmill is set to “level 0”, the running surface is as flat as it can be, and when it is set to the maximum level, the treadmill is the steepest it can go.

Levels, however, don’t really provide you with useful information because running at “level 14” on some Treadmill A, might not be the same as running on “level 14” on some other Treadmill B. It becomes difficult to deeply understand your training, and glean detailed information about the effort you use when you run. So, ideally, you want a standard measure of incline for your treadmill.

That’s where percentages and degrees come into play.

Percentage

This is most easily explained like this:

For every 100 metres forward, you climb ? metres up.

So, a 2% incline means that you’ll climb 2 metres for every 100 metres you run. Notably, this is the easiest way to think about incline, and also about elevation gain, which is not covered in this post but will be covered in another post in the near future.

Degrees

Warning, here comes some maths, specifically trigonometry. ?

A treadmill is a triangle. The running surface is our hypotenuse, the floor is our “adjacent” side, and the arm that raises the front of the treadmill is our “opposite” side. We need to solve for ?°.

Now, we can measure the length of the running surface, as well as the height of the arm’s extension, meaning that we know the lengths of the hypotenuse, and of the opposite. That means we can use “SOH” (from the famous “SOH CAH TOA”), which makes our formula the following:

$\sin (x°) = \left(\left(\frac{\text{opposite}}{\text{hypotenuse}}\right)\right)$

Solving for ?° then makes our formula “the inverse-sine of the opposite over the hypotenuse”, or:

$x° = {\sin }^{–1}\left(\left(\frac{\text{opposite}}{\text{hypotenuse}}\right)\right)$

Taking this one step further, we’ll be able to quickly work out the percentage incline from the angle. To do that, we use trigonometry again, and specifically this formula:

$\text{incline \%} = \tan (x°) \times 100$

What this shows is that 45° = 100% incline.
Logically that makes sense because at a 100% incline or 45°, you’ll go “up” one step for every step “forward”.

Most treadmills don’t go steeper than 15%, which is around 8.5°.

Alright, so!

Now that we know the methods we could use to measure incline, let’s talk about the frame of reference.

Frame of reference

In the previous section we outlined 3 different ways to measure the incline of your treadmill. In this section we’ll explore how we need to think about measuring the incline relative to the floor it’s on, and not relative to the treadmill itself.

Consider the following:

A treadmill is on “level 0”, and it rests on a perfectly level floor.
What is the treadmill’s incline percentage?

Most people would assume that this means that the incline should be 0%, but in fact most treadmills do not have a 0% incline at “level 0”!

We need to think about the treadmill as a slope relative to the force of gravity, which goes “straight down” into the floor – towards the centre of the Earth. Therefore, even though the treadmill itself could be at “level 0” (or 0%, or 0°), relative to the Earth it will have an incline! And furthermore, you as the runner will feel that incline relative to the force of gravity.

So, we need to measure the incline from the frame of reference of the Earth, or put simply:

We need to measure the treadmill incline using gravity.

On a quick aside: We have specifically designed NoblePro treadmills to have a “level 0” incline of 2% to more accurately reflect the effort it takes to run outdoors. Our treadmills go up to “level 20” which is 12%, giving you 0.5% increments.

Now that we’ve established that we need to use the Earth as our frame of reference, let’s talk about how to measure the incline of your treadmill.

How to measure your treadmill incline

To measure the incline of a treadmill, you’ll need an inclinometer – sometimes called a “digital level”. Luckily, most smartphones come with functionality that allow for this feature in apps. We don’t have any specific recommendations for apps, so please search the App Store and Play Store for your favourite one. If you want to buy something more precise, we would recommend any digital inclinometer.

The main thing to look out for would be that it has at least 0.1° accuracy. It would be a bonus if it can read out the percentage too.

If your inclinometer only gives you a reading in degrees, you can use a calculator, and plug in the degrees into the following formula to find the percentage:

$\text{incline \%} = \tan (x°) \times 100$

Step 1 – Measure level 0

Turn your treadmill on, and make sure it is on “level 0”.

Step off your treadmill, and measure the incline of the treadmill by placing your inclinometer on the top side of the machine, making sure that you don’t put it on the running surface itself.

Make a note of the percentage as minimum percentage.

Step 2 – Measure the maximum level

Step off your treadmill, and try to increase the incline. Most treadmills will not allow you to change incline while it is not running, but it’s worth it to try to see if your can.

• If it can, set it to maximum incline and measure the incline.
• If it cannot, make sure to start your treadmill, and keep it at it’s lowest speed, then increase the incline to the maximum setting, and measure the incline.

Make a note of the percentage as maximum percentage.

Also, make a note of the number of inclination levels, or steps, your treadmill has as maximum incline level.

That’s it!

Almost every treadmill assumes that your floor is completely level, and then doesn’t allow you to change the incline values dynamically. Our NoblePro Go app (Android, iOS) allows you to override the defaults we set.

Other useful formulas

Now that you have the number of steps, the minimum, and the maximum incline angles/percentages, all you need to do to calculate the incline is plug the numbers into these formulas:

Incline range (incline delta)

$\text{incline delta} ∆ = \text{maximum percentage} – \text{minimum percentage}$

e.g.: For a NoblePro treadmill,

$\text{incline delta}∆ = 12\% – 2\%$ $\text{incline delta}∆ = 10\%$

This is the range of incline percentage your treadmill has.

Current incline percentage

$\text{incline} \% = \left(\left(\frac{\text{current incline level}}{\text{maximum incline level}}\right)\right) \times \text{maximum percentage}$

e.g.: At “level 14” on a NoblePro treadmill,

$\text{(level 14)} \% = \left(\left(\frac{14}{20}\right)\right) \times 12\%$ $\text{(level 14)} \% = 0.7 \times 12\%$ $\text{(level 14)} \%\hspace{0.17em}= 8.4\%$

This is the current incline percentage of your treadmill while you’re running.

 

We hope this has been enlightening, and has given you some insight into how incline is not as simple as most people think on first impression.