While I do not run, unless a cop is chasing me. I got my dog 8 months or so ago. He is a 4 yr old Austrailan shepard and he is tireless in the mountains. Our longest hike so far is 12 miles, covering snow,ice and mud and he couldve done alot more. I am in love with this breed, although I do not believe its for everyone. Your tired from a long workday and you dont want to take a 2 to 3 mile walk? dont get one of these dogs, we average 20 miles week just around town. They are very loyal and I think he would defend me with no qualms whatsoever. They are referred to as " Velcro dogs" I cannot sit on my easy chair without him, when Im working in the yard he follows me everywhere, petbed, yeah right, try your bed.