It is my view that anything that makes your dog "get tired" works him, and anything that does not, does not.

I disagree with the idea that "all exercises are equal," and I further disagree with the idea that any "one" exercise method is all that's needed.

Of the available conditioning options, if I had to select "one" it would be a toss-up be the flirt-pole and the jenny, it sure wouldn't be an emill. To those who believe an emill (or even a slat mill) is "the same" as running, I totally disagree. For one thing, in an emill, the dog isn't using ANY strength at at all, he is just "moving his legs" so he can keep from falling. In a slat mill, the dog is at least moving the belt with his legs, thereby accomplishing some strength conditioning in the process.

By contrast, with free running or jenny work, the dog actually has to propel his whole body weight off the ground ... as the ground is neither "moving for him" (like the belt of an emill), nor can the dog "move the ground" (like he can move a mere belt in a slat mill). Because a dog actually has to carry and propel his own weight, in true running on the ground, I believe this kind of running to have more overall value to a dog ... but less overall "convenience" for the owner. I believe this is why many natural conditioners believe indoor mills to be "the lazy man's way," because in a way it is true. As with feeding kibbled dogfood, instead of feeding raw, it is simply easier for the human to do, but in the same fashion is not as good for the dog to have it done.

Sure, dogs "can survive" on kibble ... and, sure again, dogs "can get in shape" on mills ... but neither practice is OPTIMAL for the dog.

In the end, feeding raw is the OPTIMAL way to feed a dog ... and free/natural conditioning out on the open earth in the outdoors is likewise the OPTIMAL way to condition him ... the rest are just "more convenient" (for people) alternatives ... but they, likewise, are not as good. And anyone who has ever actually run a cross-country marathon, and compared that level of difficulty to just "running on a mill" in a gym, will be in unanimous agreement with this position

Jack