So I’m a qualified dog trainer as well and your reasoning is one of the most common mistakes many people make when training a dog not only for their dog’s physical fitness, but behavioral training commands like recall, stay, lay, no, etc…. The miscalculation is that you are equating your emotions with training as you say, “you know what it feels to haul a backpack and how hard it is on your body” well some people actually train with weight vest, and other resistance methods again to achieve many health related benefits, including strengthening to help prevent injury etc… So it’s really not that uncommon to see a human wearing a weight vest, etc. (I’ve trained myself many of years with weight vests) you might not like the idea of it but others may have different beliefs and goals than you. Unlike a sled dog you probably wouldn’t be able to haul about 3 times your on weight. So youå could look at that and think it’s wrong to do but it’s what they are bred to do and actually love it and it’s important to their health that they are given some opportunities to exercise their natural traits and instincts. Keep in mind with working breed dogs they’ve been bred to do tasks humans for the most part don’t have the capacity to do like a sled dog. With proper training and conditions, Huskies in particular can go more than 50 miles a day as their bodies are designed for this you see unlike humans, they can actually control their metabolism. Click on the DogMotoSports Logo below for more information about sled dogs that you were probably not aware of… 