Beta blockers and fitness tracking

[StoneLaughter]

Hello! Haven't been here in a while.

I had a heart attack on Sep 13th, and have taken it extremely seriously. I've been exercising, eating well and generally taking a great deal more care than I used to.

One area where I still don't really have a proper "grip" on things (my autism makes this important to me) is that I have a lack of clarity on how to use my Fitbit Versa 3 fitness tracker to properly track my heart rate and properly indicate when I'm doing "fat burn", "cardio" and "Peak" levels of exercise.

Before September, my RHR was between 80-90; at 54 years old, my theoretical max HR is 166 (220-age). Since starting the beta blockers, my RHR is 55, give or take; which means it's come down by 30. I have therefore set my MAXIMUM HR in FitBit to 140 (26 below my theoretical max). I know I can probably go above that but I'm trying to err on the side of caution.

Is there any definitive guidance on how to calculate Max HR, HR Reserve and exercise HR zones when taking beta blockers? Is there any definitive guidance on safe HR ranges when taking beta blockers? Is my maximum still 166?

Without clarity on these things I'm feeling really uncomfortable - and no amount of telling me to relax about it all is going to help...

Thanks!

[Mikedabike]

What a good post, and good to see you are taking your rehab so seriously. Have you tried contacting the cardiac rehab team. I found their advice invaluable when I returned to exercise. Although I was fit before my AVR, I found that post op I was very nervous about returning to exercise and overdoing it. They provided me with what they considered safe training zones while I was on beta blockers. Luckily I wasn’t on them for long, and once off the beta blockers they readjusted my heart rate zones. I know it’s purely psychological, but this gave me the reassurance as to how hard I could push things. If I could add one thing I have learnt since my own surgery. Although you have the training zones as a guide, also get used to listening to your body more than you ever used to. If you feel tired or out of sorts, don’t be afraid to have a day or two off from your exercise regime.

[Nathan53]

Well done with your new exercise regime and sticking with it. The attached aryicle may be of interest to you: verywellhealth.com/how-do-b... was advised in rehab to reduce my max heart rate on exercise by 20 beats as this was the average reduction my beta blocker was having on my resting heart rate.

Mike makes a good point also listen to your body use max heart rate information as a guide in conjunction with how you feel. I have days when I am not at max heart rate but feel I am approaching my limit so back off, other times I feel I can give more even when at max heart rate.

[Smarticus]

As much as I love monitoring my heart rate during exercise, a better test is the "talk test" It works all the way from fit to unfit and is very specific to you. I found a random website with an explanation...verywellfit.com/talk-test-f... use this as a secondary way to monitor yourself, but the most important thing is - listen to your body! HTH (from an ex PT instructor :-))

[StoneLaughter]

Thank you all - what great responses. I talked to the CR team yesterday and they stuck with the talk test line as the primary, but to assuage my concerns they're booking me in to re-do my stress test; when I did the initial one, it was on the bike and I think I was too quick to quit because bike seats give me discomfort and numbness out front.

This time they're going with the stepper; but in the interim they've used my description of how I feel to help set realistic heart zones to go with until the new test. They're saying not to go above 130 (roughly) as they think that's my 85% mark; and that bears out my manual observations on my own heart rate when my fitbit says 140/150+!!!!

In other news, I know my strength and fitness are improving; so I know I'm not overdoing it but it's good to know I'm not putting myself at actual risk from the numbers, too.

Thanks for the resources you've linked; they're going to be very useful.

[StoneLaughter]

All - I did my repeat fitness test and scored 10.8 Mets! (The average healthy white British 54YO male scores 9.6). So - regardless of any other considerations I'm delighted with my cardiac fitness. Thanks for all your words of encouragement.