Bob, a 54-year-old client, is interested in learning more about a "pressor effect." Bob has been disabled for 25 years and is in great shape, exercising regularly. He is wheelchair bound and has some use of his abdominal wall but no use of his legs. He frequently uses the Free Motion equipment to work out, so he has great upper body ability.
When using your upper extremity only for long periods of time (such as hand cycling), your intrathoracic pressure increases, which in turn increases your blood pressure and heart rate. Sometimes Bob finds his heart rate is around 180. Is this okay? How much pressure can he tolerate? What type of training should we include in his routine to improve or, better yet, lower his pressure/heart rate? He is not training for anything but does wish to remain active and ride.
The pressor effect is a rise in blood pressure seen from a rise in intrathoracic pressure and therefore causing an increase in heart rate. While this may sound detrimental, the body is very efficient in compensating for this increase in pressure and heart rate so that it does not allow damage to the cardiorespiratory system for a disease free, active individual. Intrathoracic pressure also increases as a result of expiration as the diaphragm moves higher and the intrathoracic cavity becomes smaller.
That said, what is more important pertaining to the question at hand is that heart rate is not always a true marker of gauging the intensity of exercise. In cases of stress, lack of sleep, dehydration, overtraining and possible environmental changes, heart rate can vary well over 5-10 beats per minute; therefore, heart rate should be used as a monitoring device only along with other measures such as speed, pace/power and rating of perceived exertion. All of these factors combined will produce a much more accurate interpretation of the intensity of the training session than just heart rate alone.
Along those lines, without knowing more information about the athlete, I would say that a heart rate of 180 beats per minute should not be alarming because it seems higher than what normal equations would predict training heart rate zones to be. A very accurate method of determining proper training heart rate zones, and thus knowing exactly what heart rates are too high based on fitness level and training goals, is by way of a lactate threshold test. This is where a small amount of blood is sampled throughout in order to measure the absolute amount of blood lactate that accumulates and cannot be effectively cleared by the body throughout the test.
I have personally seen heart rates in the low 200 range for training intensities and others in the high 160 range, so there is a great deal of athlete variability due to genetics and age.
While it is known that exercise can elicit a positive benefit on blood pressure over time, I would encourage regular, rhythmic breathing patterns during exercise so that the breath is not held too long or exhalation is slowed too much in order to minimize the intrathoracic pressure response. Combined with a lactate threshold test interpreted by an experienced exercise physiologist/coach, you will have drafted a safe and effective heart rate training strategy to improve health and performance.