I want to improve my cardiovascular strength. As I understand it, to do this I need to exercise strenuously enough that my heart rate goes up into the “cardio zone”, which is about 150bpm. However, I take atenolol, a beta blocker, for anxiety issues. Atenolol slows your heart rate (among other things) and, in practise, it’s almost impossible for me to get my heart rate up to 150bpm. Normally, I can get it up to about 120, and that’s only when I exercise hard.
Given that I can’t actually reach the “cardio zone” (and given that stopping the beta blockers just isn’t an option for me) will doing cardio actually do anything to improve my cardiovascular strength? I’ve asked my GP and he didn’t know.
Note: I am not a cardiologist, I am a family medicine physician, but a large chunk of my practice includes cardiology.
You are still getting an adequate workout from a cardiac standpoint, for the most part. Beta blockers do decrease some people’s ability to exercise, but there is a training effect, and most people can maintain a vigorous exercise routine on those meds.
And keep in mind that heart rate is just one way to indirectly measure the effectiveness of an exercise regimen, it’s not the thing that actually improves cardiac fitness itself. If you can maintain a brisk walk or jog that leaves you breathing a bit heavier yet able to carry on a conversation with a person alongside you for at least 20 minutes, you are getting a level of exercise that improves cardiac fitness, regardless of heart rate achieved. Increase the speed and/or time, and you’re getting more benefit.
That’s the simple version anyway. The more complex version has me telling you about METs and oxygen consumed, etc.
The American Heart Association says you still reap the benefits of cardio on beta blockers. What you cannot do is use your old target heart rate as your clue that you’re doing it right.
They suggest:
Note that if you’re on a beta blocker, it’s likely because your heart isn’t working quite right. It’s especially important that you “check with your doctor before starting an exercise program”. MOST people on beta blockers can and should exercise. A very few should not.