You may opt to run on a treadmill because it is convenient but you may be choosing the treadmill because it is easier as well. Have you ever run three miles on a treadmill and thought, "That was a piece of cake," but then when you run three miles outside you think, "I thought I was in shape; that was so hard!"
The reason is that running on a treadmill is a lot different than running outdoors and here are several reasons why:
- The rearward rolling treadmill belt offers help to your legs by pulling your feet back underneath your body, which means you could be exerting less energy to move your feet and legs than if you were running outdoors on a surface that doesn't give your legs momentum.
- When you run on a treadmill, you do not have to overcome any kind of wind resistance, which means you'll use less energy than if you were running with wind resistance.
