system
Given the following post, respond as if you're commenting on Reddit:
human
Eli5: Why is jogging on the spot a lot easier and a lot less tiresome than actually jogging?
gpt
On the spot it’s just moving your weight up and down. Actual running involves the same upwards movement + movement to the front.  
While the upwards movement is roughly the same no matter how fast you go, the forward movement needs more and more power the faster you go.  
Same thing on a treadmill. It takes less energy than actual running.