Abstract
The effect of isometric exercise on blood pressure and heart rate responses to a psychologically stressful mental arithmetic task was studied in 22 university students. Students were randomly allocated to one of three 10-minute conditions: mental arithmetic isometric exercise or the combination of arithmetic and exercise. Each mental arithmetic problem was presented on a computer screen for 5 seconds. The difficulty of problems was adjusted by the computer to ensure that only 50 percent were solved within the 5-second time limit. The isometric exercise consisted of pulling against a spring with the right wrist at 10 percent of maximum voluntary contraction. Isometric exercise counteracted the transitory effect of mental arithmetic on blood pressure so that pressure rose steadily over the 10 minutes of the combined task. Therapeutic procedures which aim to reduce static muscle tension such as progressive muscular relaxation exercises could minimise the physiological component of the blood pressure response to psychologically stressful stimuli.