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The adverse effect of lack of exercise on the blood pressure is well known. A sedentary life frequently leads to chronic hypertension, and in turn, high blood pressure can lead to heart, brain, and kidney damage.
We will address the topic of chronic hypertension in a separate article. Today, we will discuss a phenomenon called “hypertensive response to exercise” which can occur in seemingly healthy subjects who have no history of hypertension but whose blood pressure during exercise seems to increase “too much.”
As a brief background, we should point out that the blood pressure varies all the time, even from one minute to the next. The reason being that the pressure inside the arteries reflects the intensity of movement of the blood throughout the body, and this movement changes all the time in response to the changing needs of the body and to multiple factors.
Many organ systems participate in the control of the blood pressure at various times, including the heart and blood vessels, the nervous system, the kidneys, and some hormonal glands. Regulation of the blood pressure is a very complicated matter.
To be sure, the blood pressure is expected to rise during exercise (in particular, it is the systolic blood pressure that goes up), and it returns to normal within a few minutes of rest.
In some people, however, the rise in blood pressure seems “excessive” or above the level of increase habitually seen. Cardiologists and exercise physiologists who encounter this effect during a treadmill or stationary bicycle stress test call this phenomenon a “hypertensive response to exercise” (we’ll abbreviate it HRE) or, alternatively, an “exaggerated blood pressure response to exercise.”
The phenomenon of HRE immediately raises several questions:
- Can we define HRE precisely? Is there a specific number over which one can say for sure that the blood pressure during exercise is “too high”?
- What is the significance of HRE in the short term? Is it dangerous?
- What is the the significance of HRE in the long term. Is it a marker of future risk of hypertension?
- Could it be that HRE occurs primarily during stress tests, but not when people are exercising for recreation?
1) Is there a cut-off number? Unfortunately, the answer to this question is “no.” There is no standard, satisfactory threshold number that allows us to confidently separate people who demonstrate HRE and people who do not. Since the blood pressure varies so widely depending on a number of factors, identifying specific cut-off numbers is elusive or misleading. Some researchers have used a systolic blood pressure cut-off value of 200, others 210, and still others 220 to define HRE. The inability to define a cut-off point makes the other questions difficult to answer also.
2) What are the short-term effects of HRE? For the most part, if everything else seems OK, the subject feels fine, and there are no abnormalities on testing, most experts agree that having HRE is not by itself a cause for concern during exercise, so athletes who demonstrate HRE (however defined) should not be alarmed on that basis.
For some people, however, the elevation in blood pressure with exercise is accompanied by other signs of problems. They may feel particularly short of breath, and the ECG may become abnormal. If images of the heart are taken during such cases, it is not uncommon to see that the heart is struggling and not squeezing as well as it should. This more worrisome response typically occurs in people who have more advanced underlying cardiovascular disease. Such cases may indicate that treatment for high blood pressure should be intensified.
3) What are the long-term effects of HRE? Unfortunately, because HRE is hard to define precisely, studies are not providing clear-cut answers to this question. Some scientists think that HRE could be an early sign of hypertension. In other words, the person is at a stage where the blood pressure is high during exercise only, but in a few years, it may be high at rest as well. This concern has not been confirmed in all studies looking at the long term effects of HRE.
Some studies have raised a concern about an increased risk of future cardiovascular complications, such as stroke, but this has not been supported by other investigations.
A recent study using a new and sophisticated ultrasound technique has suggested that the hearts of people with HRE may be under subtle strain during exercise. At this time, this finding must be considered preliminary and is not by itself a cause for concern.
4) Could it be that HRE occurs only because of the stress of the stress test? There is no good answer to that question because it is hard to measure exercise blood pressure accurately outside of a clinic environment, or at least, it has not been done on a large scale.
There is some reason to think that HRE could be equivalent to “white coat hypertension,” which describes the fact that some people have a high blood pressure only when they go to the doctor, but not when they are more relaxed at home. One study showed that some people who have HRE during a stress test may not have it again if the stress test is repeated a separate time. Having gone through it the first time, the subjects may be more relaxed the second time.
On the other hand, even if HRE is “stress” related and equivalent to white coat hypertension, that does not mean that it is completely benign. People whose blood pressure increase excessively because of stress seem to be at slightly higher risk of long term cardiovascular complications compared to those whose blood pressure is always in a normal range.
What is the take home message from all this?
Generally-speaking, we are not too concerned by HRE, but here is our approach:
First of all, we make sure that our instruments are well calibrated and we measure the blood pressure during exercise manually. There is wide consensus that the automated devices are not reliable during exercise, and even with careful manual measurement, only the systolic blood pressure can be noted with reasonable accuracy.
When we encounter high blood pressure during exercise but all other signs are healthy, we do not raise any alarms. Routine monitoring of the blood pressure during an annual physical examination is normally sufficient.
If there are other subtle signs of concern during the comprehensive examination, we may suggest closer monitoring or additional testing. Ambulatory blood pressure monitoring is a relatively new technique that measures the blood pressure automatically during a 24-48h period of time. The test provides a lot more information than the standard blood pressure measurement at the doctor’s office, and in some countries (the United Kingdom, for example), it has become a routinely ordered procedure to screen for hypertension. Some other tests that measure arterial elasticity may also be of value.
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Dr. Accad
Thanks for the article.
I have controlled hypertension though an ace inhibitor.
My workouts are intense ( circuit style training w/ weights and aerobic,,). I decided to test my blood pressure in between sets and noticed that my diastolic gets as high as 115. Upon cessation of exercise it quickly goes down to normal range of 78-83.
Many articles I read say you should cease exercise if your diastolic hits 100, others say powerlifters are constantly at high fluctuations during lifting.
Is this dangerous and should I even expect accurate BP results while standing and breathing heavy from the exercise.
Thanks,
Charles
Those are good questions, Charles, but they are hard to answer definitively in this case because your workouts combine different exercises, and also I cannot say how reliable the blood pressure measurement between sets is, under the conditions you describe.
Yes, power lifting will raise both the systolic and diastolic pressure, and sometimes to extremely high levels. I am not familiar with the recommendation to cease exercise when the DBP hits a certain number, and I wonder if it is made based on sound clinical evidence.
After exercise, it is typical for the blood pressure to drop because all blood vessels remain dilated for a while. That blood pressure is not necessarily representative of the “resting” blood pressure that one would obtain on other occasions, and therefore should not be the gauge by which you determine that your blood pressure is well controlled. (In other words, your average restig diastolic BP may conceivably be higher than that).
Best wishes,
Dr. Accad
During a stress test last week the test was stopped before I said I could do no more. I was told it was stopped because of my high blood pressure. I do not know the exact number but I was told it was about 120% of max anticipated. I have been a runner for over 50 years. At 81 I think my max is 139 and 120% would be 167. A year ago I bought a fitbit. I looked back at previous runs and my bp is usually in the 160+ range during my runs that have become run walks in the period since I was diagnosed with Afib last year. The max today 171. Over the last 4 years my resting pulse rate has been going up from 40s to 88 during my last doctor visit. During this time my resting blood pressure continues to be normal 115/70 but if anything tending down. Last doctor visit 99/67. Starting next week my doctor wants me to wear a 24 hour monitor for 4 days. Any comments about these data points and how the results fit with current ideas about the cause and affect. My results are most likely not white coat induced since extend results with the fitbit seem to confirm the stress test results.
Regards,
George Nereo
Hi George,
I cannot comment specifically but there may be some confusion about the exercise blood pressure and the exercise pulse rate. I suspect the stress test was stopped because you have been at 120% of estimated maximal pulse rate, not blood pressure. There is no such thing as a percentage of maximal blood pressure used in clinical medicine.
Hello Dr Accad. Thank you for you research. I had a stress test last week which was stopped early as my systolic BP went over 230. I have had biannual stress tests since 2008 when I requested one as a precaution before my first marathon. I have always been symptom free. In previous tests I reached stage 6 on the Bruce protocol (18 min). I am 63 yrs old. I do regular heavy cardio exercise. For the past 10 years I have annually run 2-3 marathons and one Ironman triathlon as well as several shorter races. My max heart rate is about 183. I regularly train in the 170s. My average HR for a marathon is 150-155 BPM. My normal resting BP is 130/80. Do you think my “exercise hypertension” is a serious concern for training/racing? Thank you.
Hello Murray,
My first reaction is to wonder if the high blood pressure reading was correct and not an artifact. It can be difficult to accurately record the blood pressure during exercise, and some automatic devices may have a hard time with all the arm motions going on. Was the high BP verify manually? I personally check the BP myself during stress tests.
If the BP was indeed high, I would also want to know if it became high at a low effort level (that you might sustain during a marathon) or only at the very peak of intensity. If the latter, then your usual pace of exercise may not be an issue.
Hope that helps.
Dr. Accad
Hello Dr. Accad,
I find your site and the questions very interesting. I do have high Blood pressure and take medication for it which keeps it within normal ranges. (I’m 71). My weekly exercise consists of walking with a brisk walking group, cycling 18 miles on undulating surfaces but not hills and golfing with occasional visits to the gym. I do have cardiovascular disease with the stenosis between 50% and 70%. The disease is hereditary and my cholesterol levels are normal although I do take a preventative statin. For Several years I have gotten very out of breath on inclines. My chest gets tight and my thighs get fatigued so I was sent for a stress test. My heart appears fine, but my blood pressure went up to 238/96. During my previous stress test 6 years ago when I was not on BP meds, my blood pressure went up to 300 when lying down after the test ended. As I started to cough afterwards the internist is recommending a lung test although I don’t usually cough during exercise. Do you have any comments or suggestions? Thank you.
Hello Eileen,
It seems possible that the your high blood pressure response to exercise would play a role in your symptoms. I cannot make any more specific comments about that or about your lung issue. Hopefully, you and your physicians can get some clarity on this soon.
Best regards,
Dr. Accad
Thanks for the interesting article. I’ve had hypertension since I was 20. I’m on 4 medications. I’ve been a runner for years and love running. Though I’m not running the 1/2 marathons I used to 10 years ago, I exercise a lot. I am struggling with a super high heart rates during running and dizziness and numbness in my arms during strength training. Running a 12 minute mile (5mph) my heart rate is staying at 180-185. Today I was up at 191. Last year I did Orange Theory Fitness (HIIT/Cardio) 5 days/week for a year and my heart rate/fitness levels never improved. I did have a stress test about 10 years ago and everything was fine. They had me wear a heart monitor for a 2 weeks and they said the results are fine. Went to the doc recently to address the complaint and they did a resting EKG and everything is fine. So basically my heart is fine, but this is not getting better and I don’t know where to turn. I can’t stop exercising because I need to lose some weight. I suspect my blood pressure is spiking when I’m exercising but I’m not sure why, what I could do about it, or where I could even go to investigate it. Any advice on next steps for me?
Hi Laura,
Thank you very much for your comments, Laura. We cannot give any specific medical advice without knowing the particulars of your case. To do that would require a thoughtful doctor to go over everything carefully. We’d be happy to see you in our clinic but, short of that, we recommend that you bring your concerns to your doctor.
I know I should wait to hear results from my muscular stress test I had 2 days ago, but, I can’t. I went the whole route walking near the end at 5 mph and an incline at 14. They said I did well but my blood pressure went to 220/102. I’ve never seen those numbers. Before I started, it was 185/100. Never came close to that. I’m typically 145/80. I feel fine. But could I still be in trouble? Was it just the white coat theory?
Thank you for your comments, George. We really cannot make any determination without knowing the particulars of your case and medical history. Hopefully your physician will be able to help you out with your concern.
Hello Professor.
Hope you are well.
I would like to know if you are aware of any good wireless blood pressure monitors, that give reliable data during exercise (not rest)?
Also, what previous assessment would be need to safely prescribe exercise with some periodos at 90% Max HR and the majority within 70-90% Max HR?
Finally, do all severe hypertension patients are prescribed with drugs? Or not all?
Thank you,
Jorge
It is clear that most people are concerned about high blood pressure during exercise. During a recent stress test, my doctor was surprised that my blood pressure only reached 130. The nurse and the doctor both checked it) My pressure is normally low (110/70) but during an earlier test it reached 158, being expected.
Is a relatively low blood pressure during heavy exercise a concern?