I've always wondered why treadmills have inclines. It seems to me that, on a pure physics level, you shouldn't be expending any more energy, since you're not actually doing any lifting. Of course, human bodies are not simple physics experiments.

What fitness benefits does a higher incline bring when exercising on a treadmill?

  • The thread is actually moving you down and you're stepping up a bit increasing the amount of calories burned slightly. But as far as I know it's mainly to give the knees an easier 'step' so the 'fall' isnt as hard on you knees. Jul 28, 2011 at 8:01
  • @Coding - no, it actually uses more energy. JoJo explains below. A simple explaantion: if you did not walk, the machine would move you 100s of meters downwards each hour. (- assume it was an enormous machine!) So, you are truly lifting yourself up hill. If this still does not visualise it for you: imagine you are at the top of an escalator, facing the "wrong" way, and you let the escalator take you all the way down. Then, at the bottom, you run on the same escalator really fast to the top. Repeat that many times. You can see, you are really lifting your body.
    – Fattie
    Jul 29, 2011 at 11:51
  • Re: that it doesn't seem like it would be expending more energy...This is a question best answered by getting on a treadmill, set to no incline and 4-5 mph brisk walk for a few minutes. Easy, right? Then set it to the maximum incline (probably 15%), and try again...and oh my will you know. :D
    – Chelonian
    Nov 19, 2013 at 5:29

1 Answer 1


When walking on a flat plane, your knees don't bend as much. Your hamstrings will do most of the work.

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By walking on an incline, your knees bend more and as a result, your quads can be used to extend the knee back to the straight position. The greater stretch on your glutes allows them to generate more power to thrust the leg backward. The more acute angle of your foot will help exercise ranges of the calves which you aren't used to in daily walking.

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You will burn more calories on the incline than the flat plane, granted that both are set on the same speed. This is because you need to generate an additional [mass * gravity * sin(angle)] newtons to move upward. On a flat plane, the angle is 0; sin(0) = 0, so no force is used to move upward.

In conclusion, the incline will work a larger range of muscles. But I don't think the incline is necessarily better than the flat plane. The point of the threadmill is to do cardio, not build muscle. But if the angle is particularly steep, it can be used to increase muscular endurance of those particular listed muscles somewhat.

  • Seems like you'd typically want to do both low and high inclines so that you work everything. Jul 28, 2011 at 15:22

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