A cat that does not run at all in a room runner and a cat who runs hard

Although I tried running the cat with that room runner that I can walk and run at home feel freely, it seems that there are about two patterns in cases where it does not run at all and when it runs.

Playback is from the following.
First of all, if you do not try running hard ...... No matter what you do, waste.

Very Lazy Cat On Treadmill at Shoutfile.com

And if you run hard and run. Smile.

YouTube - Treadmill Kittens