Before you go above recommended HR's for your age, you really should have a good workup and stress test to set your baseline. ou may find you can run it up to 22o, or you may find out that you have an underlying undiagnosed heart issue and can't run it above 100. BEtter to be safe than sorry. I'm coming back slowly from heart issues, I had a coronary event occur on April 9 with no previous warning. The day before, I had my standard RHR of 48-54 BPM, and the next day, I was leaving class in the AM, had a funny little blip of pain, threw up, and hit the floor. Woke up in the hospital in AFIB, with a HR that was irregular, and cycling between 165 and 220, missing beats, throwing PVC's and SVT's.

It can sneak up on you after 50.