How much work can a young dog do without being physically or mentally stressed?

Hi Cindy,

First I want thank you the hard work you, Ed and the rest of your team all the long hours you must put in to make this world a better place for dogs and their handlers. I was lost trying to do training with the new fad of trainers using halties and other training methods that were not working. I had a young mal and she was a handful. I stumbled on your site and was saved from daily frustration. Between you and Michael Ellis, I now have a wonderful SAR wilderness dog. My question is about how much work a young dog should do when training for searching in the wilderness and be physical stressed or mentally for that matter. I've seen few people try to finish their pups at just barely one year of age. The test is a 3-4 hour 100 to 120 acres over rugged terrain. I would appreciate your guidelines of this. My thoughts are it's a little to much training for young developing pups.