I actually asked my vet about this when we went the other day, and she said that there aren't any physical problems that Yorkies will get from running (like who German Shepards have joint and hip issues that can be made worse by running often). But that he should be fine especially since he is 7lbs and not a tiny yorkie, as long as it builds up gradually. I won't take him on my runs that are any longer than 2 miles or so though.
I hate when I go for a run and decide not to take him with me, because I think he will be too tired (like if I had him run with me the day before, or if I am going farther than 2 miles), because he gets angry/sad when I don't take him on a run. He knows my routine of putting my running clothes and shoes on, and my garmin watch and stuff on, and he starts getting excited and goes to the door to have his leash put on lol. So on those days when I make him stay back I feel bad
But then I take him for a walk later
