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Runners have always argued about which is better, running on the treadmill or running on solid ground.

Although both are using the range of motion they are very different in many ways. Running on the treadmill is of course (duh!) easier than running outside. First is that the belt on the treadmill "helps" when you are running, making it easier to run and without much push on the ground.Some of the "conditioning" that happens with outdoor running does not occur with treadmill running because the plate or base on the treadmill gives more than road surfaces. Add to the fact that you don't encounter air resistance, rain among other things when your running in the treadmill.