I take 70 mg. of Propranolol along with 200 mg. of Topamax daily for my migraines which are chronic. I found that the combination of the two drugs has not eliminated my migraines but has lessened the severity of my attacks. I still get 2-4 migraines a week but am able to manage them with abortive medications. It is rare for me now to end up in with those horrible 24-48 hours where I am curled up in bed and in constant pain just waiting for the agony to go away. While I would love to take less medicine, I consider my life to be in general more manageable. The combination of the two drugs probably does make my more tired, but I have been taking it for so long I don't know any different. I try and exercise when I can...yoga, walking, slow jogging....but have gone as long as a year with no exercise when my migraines were particularly bad. The only thing I did notice is that I did try and withdraw one time from the Propranolol when I was feeling particularly healthy. I tapered very slowly but suffered chest pains and severe migraines which were quite alarming considering I was on such a low dose. I had already tapered down from 300 mg. to 200 mg. of the Topamax and was hoping to eliminate the Propranolol as well. I have very low blood pressure normally (100/60) but I can't say as I saw that it made any difference in my ability to exercise. Your heart rate may not register as high but you are obviously still getting all the benefits of a workout. Good luck with whatever you decide!