|
|
||||||||
Journal of Applied Physiology, Vol 71, Issue 4 1469-1476, Copyright © 1991 by American Physiological Society
ARTICLES |
S. Y. Huang, K. W. Tawney, P. R. Bender, B. M. Groves, R. E. McCullough, R. G. McCullough, A. J. Micco, M. Manco-Johnson, A. Cymerman, E. R. Greene and al. et
Cardiovascular Pulmonary Laboratory, University of Colorado Health Sciences Center, Denver 80262.
Cerebral blood flow and O2 delivery during exercise are important for well-being at altitude but have not been studied. We expected flow to increase on arrival at altitude and then to fall as O2 saturation and hemoglobin increased, thereby maintaining cerebral O2 delivery. We used Doppler ultrasound to measure internal carotid artery flow velocity at sea level and on Pikes Peak, CO (4,300 m). In an initial study (1987, n = 7 men) done to determine the effect of brief (5-min) exercises of increasing intensity, we found at sea level that velocity [24.8 +/- 1.4 (SE) cm/s rest] increased by 15 +/- 7, 30 +/- 6, and 22 +/- 8% for cycle exercises at 33, 71, and 96% of maximal O2 uptake, respectively. During acute hypobaric hypoxia in a decompression chamber (inspired PO2 = 83 Torr), velocity (23.2 +/- 1.4 cm/s rest) increased by 33 +/- 6, 20 +/- 5, and 17 +/- 9% for exercises at 45, 72, and 98% of maximal O2 uptake, respectively. After 18 days on Pikes Peak (inspired PO2 = 87 Torr), velocity (26.6 +/- 1.5 cm/s rest) did not increase with exercise. A subsequent study (1988, n = 7 men) of the effect of prolonged exercise (45 min at approximately 100 W) found at sea level that velocity (24.8 +/- 1.7 cm/s rest) increased by 22 +/- 6, 13 +/- 5, 17 +/- 4, and 12 +/- 3% at 5, 15, 30, and 45 min.(ABSTRACT TRUNCATED AT 250 WORDS)
This article has been cited by other articles:
![]() |
N. H. Secher, T. Seifert, and J. J. Van Lieshout Cerebral blood flow and metabolism during exercise: implications for fatigue J Appl Physiol, January 1, 2008; 104(1): 306 - 314. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. H. E. Imray, S. D. Myers, K. T. S. Pattinson, A. R. Bradwell, C. W. Chan, S. Harris, P. Collins, A. D. Wright, and the Birmingham Medical Research Expeditionary Soci Effect of exercise on cerebral perfusion in humans at high altitude J Appl Physiol, August 1, 2005; 99(2): 699 - 706. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Gonzalez-Alonso, M. K. Dalsgaard, T. Osada, S. Volianitis, E. A. Dawson, C. C. Yoshiga, and N. H. Secher Brain and central haemodynamics and oxygenation during maximal exercise in humans J. Physiol., May 15, 2004; 557(1): 331 - 342. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |