Hi there! My b-boy Jack is just about 3 years old & we run (jog) 4 to 4.5 miles and walk another 1 to 2 just about every day. We built up to that by alternating short segments of jogging with longer segments of walking, and gradually adding to the distance we jog. It’s taken about a year to build up to doing this distance as often as we do. We go out before dawn, but even then I’ll dial it back if it’s too warm. He keeps up just fine with my galgo, and hasn’t shown any signs that we’re over doing it.
I love my morning runs with my boys - I hope you have a great time training with your pup!