
Originally Posted by
CA Jack
Aside from a more natural, full run being achieved on the jenny, the fact is (running a mill) a dog is "moving a belt" ... but on the ground a dog (running a jenny) is propelling himself forward ... which is a major difference.
Anyone who's ever run a treadmill in a gym "moving a belt" will tell you it's a joke compared to actually running cross-country outside ...
Jack