Blood pressure and heart rate during rest-exercise and exercise-rest transitions.
The transients of mean arterial blood pressure (BPa) and heart rate (fc) 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 BPa 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 fc and BP during the first 6 s. In phase 2, BPa decreased while fc continued to increase. During phase 3, BPa and fc 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 fc.
Baum
K
K
Physiologisches Institut der Deutschen Sporthochschule Köln, Cologne, Federal Republic of Germany.
Essfeld
D
D
Leyk
D
D
Stegemann
J
J
D000328:Adult; D001794:Blood Pressure / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D012146:Rest / Q000502:physiology*