I am assuming you are combining your work out with you dog, and that sounds good, but.
It may only be my mini=schnauzers, the male likes to walk fast, and the female is slower likes to investigate. So I take them out individually, and boy do I end up with the best work out not by choice. I time my walks not the distance. It seems to me just walking at a steady pace, they do not enjoy the walk. They both Like to stop and smell, p, and just look at something that caught their interest. Then we carry on. I had a neighbor that would walk her lab around the circle, we live on like an island is surrounded by a dirt road goes around us. She would walk at a very fast pace and never let her dog stop once, and you can tell the dog wanted to take a leak, or just take a second to smell. I just feel part of taking dogs out for a walk jog, stopping at various intervals makes for a more exciting walk for dogs? Oh, when My dogs really get a work out, they are off leash so they can go full speed, and they do especially when some one is passing by our fenced yard. The only time I ever carry my dogs back, is when they go into deep snow, and then decide oh oh, I went too far!lolo