hyperthroidism and exercise

Good afternoon my question is I was just diagnosed with hyperthyroidism and i'm currently training for a half ironman. My doctor put me on Inderal 10mg twice a day and I feel horrible while exercising. I have heavy breathing and get winded easily and can't exercise like I used too.  A half ironman consists of 1.2 mile swim, 56 mile bike and 13 mile run.  I haven't seen the endocrinologist yet but need some advice,  Look forward to hearing from you

[CCFCardio MD2]

I'm sorry to hear you're not feeling well.  Inderal (generic: propranolol) is a beta blocker that is often used in hyperthyroidism for symptoms relief.  I'm not sure what your symptoms were before you got your diagnosis, but if you feel worse on the propranolol then you should talk to your doctor about stopping it.  Propranolol does not cure hyperthyroidism, it is just for symptom relief so stopping it should be fine, but discuss with your doctor first.  I would also suggest seeing an endocrinologist.  Good luck with the 1/2 ironman.

Best of luck.