Bicycling, Beta-Blockers and Target Heart Rates

by Richard Ellin

Question: So now that one of your advisers has been put on a beta blocker I’d like to know what the effects have been on their cycling. I’ve been taking beta blockers for 16 years and find that the lowering of my heart rate affects my riding, and I can’t get enough blood/oxygen to the legs unless I wait till most of the medication has warn off. Any suggestions? — Scott P.

Question: I am 57 years old and have been a mountain biker for the last 12 years. I took up road biking last year. I’ve ridden just over 1,300 miles this year so far. I’ve found my max heart rate usually is 181. My average heart rate is about 148. Are there any health problems with such heart rates at my age? I ride with guys who are 10 to 20 younger. Do you see any problems riding at this pace or should I look to back off a little? — David from Little Rock

Dr. Richard Ellin Responds:

Regarding the effects of beta-blockers on heart function, Scott, there is no question that they can reduce the magnitude of increase in heart rate with cycling (or any endurance exercise). For most cyclists, this would probably not be noticeable, but for competitive cyclists it could be noticeable at maximal efforts. Nevertheless, I would caution you, and any cyclists taking beta-blockers, not to stop or omit their beta-blockers without consulting with their doctors, since the effects of missing doses could be harmful.

Now, let’s talk about heart rates and, specifically, the benefits of certain HRs. For most recreational roadies, the approximate maximal target heart rate one should aim for during exercise can be estimated using the following formula:

Goal heart rate = (220 – age) x 0.85.

Thus, for a 50-year-old, it would be approximately 144. Most studies indicate that if one achieves this heart rate and maintains it through exercise, such as cycling, one gets the full cardiovascular benefits of training. There is little additional benefit in attaining higher heart rates.

Provided that one has a healthy heart, however, there is no danger in attaining heart rates in this range, or higher. The risk of attaining much higher heart rates, such as the 181 David asks about, is proportional to how healthy the heart is. Only if you have your heart thoroughly checked out by a physician, and it’s found to be in excellent health, would attaining a heart rate of 181 be safe.

For anyone questioning whether or not they have a healthy heart, only an exam (and perhaps some testing) by their doctor can determine that.

Richard Ellin, MD, FACP, is a board-certified specialist in Internal Medicine who practices in Alpharetta, Georgia. He received his medical degree and completed residency at Emory University, and has been in practice with Kaiser Permanente more than 25 years. He is also an avid cyclist.