The best conditioning, by far, is giving the dog the opportunity to tend sheep. An hour on a big graze confining sheep a couple times a week, really works everything the dog should have. The dogs move at their own speed, no lead, up and down hills, shortening and lengthening their strides as necessary. Tightens ligaments, tightens backs, even tightens feet. And the best thing about it, it allows the dog to exercise his mind. He/she needs to think about where he or she needs to be at all time. I've seen it work miracles on older dogs. And the best part is watching the dog do "his thing" and seeing the standard come to life. Susan PS This is not the gather fetch type of work you see on the A course in AKC trials, but what the dogs did in Germany when Von Stephanitz first saw them. Susan w. Sullivan Firethorn Farm German Shepherd Dogs Where Form Follows Function