I knew some guys that used it in my area, some had success with it, others did'NT. I noticed that in some of the hog hunts compared to previous hunts with the same dog, they looked weaker in my opinion. I believe part of it was that at the time a lot of people bought into the free conditioning method and lost focus on strength training and actual endurance work, in previous hunts these guys used a lot of hand walking a little weight pulling and basically tossed a ball back in fourth allowing the dog to open up in sprints and at the same working those fast twitching muscles. I am in no way saying it wasn't a good keep just my observation.