Exercise More Effective Off Beta Blockers?

[davecom]

Hi everyone,

I emailed Dr. Fu (Yes controversial Levine protocol co-author) about this tonight as well. Basically, I am wondering whether the blunted heart rate during peak exercise on a beta blocker makes the exercise somehow less effective than exercise done off it. In other words would following the Levine protocol while on a beta blocker be less effective than following it off one? In the original study he only accepted volunteers who were not on a beta blocker, but the big cross country study does accept patients on beta blockers. Anyone have some insights? Perhaps there are non-POTS resources about the effectiveness of exercise on beta blockers versus off (I tried Googling)?

[looneymom]

What is a blunted heart rate? I've heard this term before. Could you explain it to me?

[Guest Alex]

Dave,

I don't have a straightforward answer for you but I have some articles that might come in handy - I'll attach them below. Instead I can tell you that in my case, being on a beta blocker didn't seem to "blunt" my HR during exercise at all. I reached 120 soon after I hopped on the bike, or shortly after I started walking on the treadmill and I believe I peaked around 170 (I was later told that my max training HR off meds should be around 160). At that time I was on propranolol, florinef, mestinon and klonopin, I was drinking 3-4 L of water a day and ingesting at least 5 g salt a day!

I'd be curious to hear what Dr Fu has to say about this though.

Looneymom,

a blunted heart rate or a blunted response to exercise, means that the person is unable to reach his/her maximum predicted HR during exercise. It's usually due to meds (like betas) or excellent conditioning (highly trained athletes tend to have this kind of response). I also believe there are certain medical conditions that can manifest with a blunted HR, particularly in those with altered baroreceptor function.

Here are the articles:

http://hyper.ahajournals.org/content/58/2/136

Exercise Training in Postural Orthostatic Tachycardia Syndrome Blocking the Urge to Block β-Receptors?

http://hyper.ahajournals.org/content/58/2/167.full

Exercise Training Versus Propranolol in the Treatment of the Postural Orthostatic Tachycardia Syndrome

http://www.ncbi.nlm.nih.gov/pubmed/23616163

Low-dose propranolol and exercise capacity in postural tachycardia syndrome: a randomized study

http://physicaltherapyjournal.com/content/75/5/387.full.pdf

Effects of cardiovascular medications on exercise responses

http://www.csep.ca/english/view.asp?x=724&id=89

Exercise and Medication: How Do They Interact?

http://cpr.sagepub.com/content/10/4/296.short

Influence of beta-blocker use on percentage of target heart rate exercise prescription

http://www.fims.org/content/assets/documents/PositionStatements/Antihypertensive-medications-exercise.pdf

Antihypertensive medication and exercise

http://core.kmi.open.ac.uk/download/pdf/1441313

The Effect of Beta Blockers on HeartRate Response during the ChesterStep Test

Best,

Alex

[looneymom]

Thanks for the definition and posting these articles.

[davecom]

Thanks for the articles, Alex. My experience so far has been that my max heart rate during my 35 minute recumbent biking has increased about 20 bpm off of beta blockers (140 bpm to 160 bpm). Seems pretty inline with the articles.

Dr. Fu's response didn't really answer the question - probably because the literature doesn't really have an explanation. He just said that beta blockers lower maximum heart rate and possibly exercise capacity.