Editor’s Note: Dr. Mirkin’s article today began as a response to one of our Premium Members. Greg C. wrote us: “I ride about 4,500-5,500 miles a year. This is the first year I’ve been monitoring my blood pressure after riding and noticed the systolic drops significantly after my rides. I typically run 110-120 over 70-80, but after rides it’s sometimes barely above 95 over 60-70. Is this normal, or something to be concerned about?” After the reassuring response to Greg, Dr. Mirkin continued to write his typically thorough, educational piece that we have come to expect and enjoy.
Greg, you are normal. It is normal to have your blood pressure drop after you exercise, as long as you don’t feel dizzy at that time. For both people with and without high blood pressure, a single exercise session lowers blood pressure up to an hour and thenblood pressure returns to its previous level (Hypertension 1991;18:211-215). If you feel dizzy after exercising, you may still be normal, but an electrocardiogram taken when you feel dizzy can rule out an irregular heartbeat.
High blood pressure puts you at increased risk for suffering a heart attack or stroke and damaging every organ in your body. Lowering high blood pressure helps to protect you from all these complications (JAMA 1970;213:1143-52). Your blood pressure is too high if it is: *above 120/80 when you are lying in bed before you go to sleep at night or before you get up in the morning, or *above 140 at other times. Blood pressure is at its lowest at bedtime.
Exercise Lowers High Blood pressure and Helps Protect the Heart
Research more than 60 years ago showed that regular exercise helps protect the heart from disease and protect you from premature death (Lancet 1953;2:1111-20), and the more regularly you exercise, the greater the protection (N Engl J Med 1984;311:874-7).
Regular exercisers have significantly lower blood pressures than non-exercisers (Am J Hypertens 1989;2:60), and those who do not exercise regularly are at much higher risk for developing high blood pressure in the future (JAMA 1984;252:487-90).
Blood Pressure During Exercise
Your blood pressure usually rises as soon as you start to exercise and drops a little bit while you exercise at the same intensity (J. Appl. Physiol. 1997;82(4):1237 – 1243). However, as you continue to increase the intensity of exercise, your blood pressure usually rises higher and higher. When you run at a comfortable pace, your blood pressure can normally be 200/70. When you do a maximum-effort leg press, your blood pressure can rise as high as 480/350 mm Hg.
Extensive research shows that the people who have the highest rises in blood pressure during aerobic exercise are the ones most likely to develop future high blood pressure at rest (J Cardiac Rehabil 1983;3:263-8). People who have normal resting blood pressures, but have their blood pressures rise above 225 during running, have double the risk for developing resting high blood pressure in the next 32 months (Prev Med 1981;10:62-8). Indeed, people whose blood pressures rise above 210 during moderate running are at increased risk for developing a markedly enlarged left ventricular pumping heart chamber that may strain the heart (Ann Intern Med. 1990;112:161-6)
Blood Pressure Drops After you Stop Exercising
For people both with and without high blood pressure, a single exercise session lowers blood pressure up to an hour and then blood pressure returns to its previous level (Hypertension 1991;18:211-215). Having a systolic blood pressure that doesn’t drop after you stop exercising puts you at increased risk for heart disease (Am Fam Physician. Oct 1, 1998;58(5):1126-1130). In fact, doctors use a ratio of (systolic blood pressure three minutes into the recovery phase of a treadmill exercise test) divided by (systolic blood pressure at peak exercise). A ratio above 0.9 puts you at increased risk for heart disease.
What You Should Learn from This
1) High blood pressure puts you at increased risk for heart disease.
2) Exercise helps to lower high blood pressure and prevent heart disease.
3) Blood pressure rises after you start to exercise and drops when you stop exercising.
4) A systolic blood pressure greater than 225 during casual running puts you at increased risk for heart disease.
5) After stopping running, blood pressure drops below its pre-exercise level.
6) Having a blood pressure that does not drop after you stop running puts you at increased risk for heart disease and high blood pressure.
Gabe Mirkin, M.D., is a sports medicine doctor and fitness guru. A practicing physician for more than 50 years and a radio talk show host for 25 years, Dr. Mirkin has run more than 40 marathons and is now a serious tandem bike rider with his wife, Diana. His website is http://drmirkin.com/. Click to read Gabe’s full bio.