I am getting a rescue dog who just recovered from heart worm?

So I am getting a dog from the shelter and he had stage four heart worm, they didn’t think he would make it, but he did. Then he had baby heart worms and we got to see him and everything and they said he could only go on short walks while he had the baby worms. Well now that he is cured and everything, will he always have to only go on short walks or can he go on a long walk and possibly a short jog?
It has been like a week.