Yes, of course. Exersice is always a good thing as long as you don't go overboard to the point of exhaustion. You should exersice at a comfortable pace, making sure that you can always breathe through your nose. Exersice is one of the best things you can do for a hypothyroid, it helps to stimulate and heal it. My favorites are rebounding on a trampoline and walking. You should start exersicing slowly and build up from there. Remeber, it's not how long you exersice, it's the regularity of which you exercise.