Exercising with a toddler

My son is 2.5 years old. When I exercise at home, my son always is under my feet. He sometimes leaves me alone, but for the most part he's right there. He occasionally dances along with me, but mostly he's just kinda in my way. I try to do the bulk of my exercising when he's asleep, but lately sleep is winning so I have to do it during the day. Anyone have any suggestions on either keeping him busy or doing them with me?