Yes it sounds like you have poison ivy / oak. I also worked out in my yard a week ago Saturday and did not know that I had poison ivy in our back yard. But I sure found out today when I went to a dermatologist, that is what I have. You will need medication to cure this. Go to a dermatologist to get medicated to clear it up. If you cannot get in to see one right away ask if they can give you some ideas of over the counter medication cream to put on it till you are able to be seen. The longer you wait the worse the scarring and redness and itching will get.