Hello @joycehocm! Please do ask your cardiologist HOW Metoprolol would affect the symptoms you are experiencing. I was on Verapamil, a calcium blocker before a Septal Myectomy (age almost 76 in 2022). I was prescribed Metoprolol Succinate 50mg after surgery. I am not aware of any side effects, but that's difficult to gauge because there was no time period when I was not taking it, cannot compare a "before and after" scenario. I do start feeling a bit tired late afternoon, but that can just be the result of a busy day. I am a walker, too, usually 4 miles a day, gym three times a week for the same 3 reasons you noted. I have slowed down somewhat, is it age? I am so glad to read that you are continuing to be as active as you can. Please look at https://www.mayoclinic.org/diseases-conditions/high-blood-pressure/in-depth/beta-blockers/art-20044522 but remember that even if one person out of 100,000 reports a symptom taking the drug, it's listed as a side effect. We are all different and we are all walking chemical labs with different outcomes when something new is added to the mix. Do ask your doctor if your decreased tolerance for exertion is due to the progression of HOCM or the medication or both.