Question Title: atenolol, stress test, and exercise

I joined a fitness program last November. Because of my age (48, female) I had to have an exercise stress test done on the treadmill. I take 25 mg atenolol daily for episodes of moderate hypertension. The technician continued the test until my heartrate was at 140. He was surprised that I could go that high without any symptoms. He gave me a target heart rate of 120-140. The evaluation gave me a cardiovascular rating of "very good to excellent". I find that when I exercise I have no problems at all until I get my heart rate up to 120. At that point it seems that I can only exercise for about 10 minutes, making me wonder if the treadmill test wasn't run long enough. After about 10 minutes I have to cool down or I become short of breath and nauseated. I told my doctor about this and he said that the dose of atenolol I was taking was very small. I should just not exercise as hard. My question is, shouldn't a person who has an overall cardiovascular rating of "very good to excellent" be able to exercise longer than 10 minutes at the lower end of her target heart rate? Could this be an effect of the atenolol? Can I expect to see an improvement if I keep working at it? Thank you.

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Dear Chris, thank you for your question. Atenolol, as you may know, is a beta blocker and it slows the heart rate down while also lowering the blood pressure. For serious athletes, beta blockers can limit the peak exercise performance, but for most people, there is no significant detrimental effect on exercise. Your symptoms could be caused by the atenolol, or you may be deconditioned and not able to tolerate exercise in that heart rate range. The initial treadmill test that you did may not have been long enough to determine your sustained exercise capacity. You should expect to see an improvement in your exercise performance with time, but the key thing to remember is, "Don't push it." If you feel too short of breath or nauseated, then slow down or stop the exercise all together. An alternative strategy would be to stay in a lower heart rate (100-120) for now and gradually work up into higher heart rates.

I hope you find this information useful. Information provided in the heart forum is for general purposes only. Only your physician can provide specific diagnoses and therapies. Please feel free to write back with additional questions. Good luck!

If you would like to make an appointment at the Cleveland Clinic Heart Center, please call 1-800-CCF-CARE or inquire online by using the Heart Center website at www.ccf.org/heartcenter. The Heart
Center website contains a directory of the cardiology staff that can be used to select the physician best suited to address your cardiac problem.

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