BLOOD-PRESSURE AND HEART-RATE DURING REST-EXERCISE AND EXERCISE-REST TRANSITIONS

The transients of mean arterial blood pressure (BPaBAR) and heart rate (f(c)) during rest-exercise and exercise-rest transitions have been studied in six healthy sport students. After 5 min of rest in an upright position on a cycle ergometer they exercised for 15 min and remained seated for a further 5 min. The subjects exercised at four different constant intensities (40 W, 80 W, 120 W, 160 W) in random order separated by at least 24 h. The BP(a)BAR was determined by a noninvasive and continuous method. During the first minute of exercise, three phases of response could be distinguished, with the first two showing no clear relationship to intensity. Phase 1 consisted of simultaneous increases in both f(c) and BP during the first 6 s. In phase 2, BP(a)BAR decreased while f(c) continued to increase. During phase 3, BP(a)BAR and f(c) approximated constant values or a linear increase. Both parameters showed no comparable intensity-independent reactions during the off-transients. In conclusion, during the first 15 s of rest-exercise transitions there seems to be a fast and uniform cardiovascular drive which overrode other influences on f(c).