atenolol, stress test, and exercise

Posted By chris on March 14, 1999 at 14:27:00:







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.