Max Heart Rate on Beta blockers

[m1ekia]

I (29F) ope someone can help me or may have been through similar.

I have recently been prescribed Propranolol (beta blockers) 40mg X2 daily and an additional one when needed. My heart rate has been lowered because of it which has helped my anxiety symptoms but it does mean it is extremely rare I get above 'light' in activity.

Example- I went for a 2 hour hike today and got into moderate for a whole 8 minutes. My partner who is at a similar/slightly worse (no shade) fitness level was in moderate for 54 minutes.

It currently says my max heart rate should be 191.

[JohnnyRow]

Beta blockers definitely affect exercise heart rate by lowering your heart rate max, which is used to calculate your different exercise zones.  The default formula that Fitbit uses for everyone for max heart rate is 220 minus age, but you can manually change that to anything less than 220. There seems to be no exact formula for how much the max heart is actually lowered but one I just came across is estimated HRmax=183-0.76×age.  It probably varies with dosage and for different people but you could try starting with that and see if it gives reasonable results.  If you already know what it says your max HR is, you must already know where to change it.