To the uninitiated, watching a bodybuilder strain under a heavy weight can be almost frightening. Eyes appear ready to pop out; veins bulge; and the lifter’s face often turns crimson. Any minute you expect his head to explode. You have to wonder what’s happening to that bodybuilder’s blood pressure.
Studies have shown a significant increase in blood pressure during the lifting of heavy loads. One study found blood pressure readings of 320/250 in a bodybuilder doing heavy leg presses. In contrast, the upper limit of normal blood pressure is about 140/90. Findings such as that alarmed many doctors, who advised people with hypertension, or high blood pressure, to avoid all forms of resistance exercise, especially weight training.
Other studies showed that blood levels of norepinephrine, a catecholamine that constricts blood vessels, thus promoting high blood pressure, remain elevated for up to a day after a weight-training session. But follow-up studies revealed conflicting results, with some showing a slight rise in blood pressure following weight training and others showing a decrease. A notable weakness of such studies is that they didn’t observe blood pressure changes for more than an average of two hours after a workout, and the workouts used didn’t resemble real-world training.
In the latest study published on the relationship between weight training and high blood pressure, the researchers avoided those methodological flaws.1 They studied the effects on blood pressure in three groups over a 24-hour period:
1) Sedentary, consisting of five men and six women.
2) Resistance-trained, consisting of six men and six women.
3) Endurance-trained, featuring four men and six women.
All subjects were between 18 and 26, with normal baseline blood pressure. The authors took two blood pressure readings, the first after a weight-training routine and the other after the subjects had done no exercise for 48 hours. The actual weight routine involved two sets each on 12 different machines and trained the entire body.
While prior studies showed that bodybuilders actually had lower average blood pressure readings, likely due to a decreased sympathetic nervous system response, this study showed no changes in any of the subjects’ blood pressure. One interesting aspect was that the untrained group had the same blood pressure response as the experienced weight trainers. The blood pressure readings on the nonexercise day were similar to those taken after the workout in all groups.
Based on this study, it appears that weight training has no adverse effects on blood pressure in people who have normal blood pressure. The question arises, however, concerning the effects of intense, heavy training on people with hypertension. Most are already taking medication to treat their high blood pressure, which should allow them to respond to training sessions similarly to the way people with normal blood pressure respond. People with extremely high blood pressure that isn’t being treated should probably train more conservatively, using moderate weights and repetitions, with added aerobic training. IM
1 Roltsch, M.H., et al. (2001). Acute resistive exercise does not affect ambulatory blood pressure in young men and women. Med Sci Sports Exercise. 33:881-886.