| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Human Performance Laboratory, Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, Texas 78712
Received 16 July 1996; accepted in final form 26 November 1996.
González-Alonso, José, Ricardo
Mora-Rodríguez, Paul R. Below, and Edward F. Coyle.
Dehydration markedly impairs cardiovascular function in
hyperthermic endurance athletes during exercise. J. Appl. Physiol. 82(4): 1229-1236, 1997.
We
identified the cardiovascular stress encountered by superimposing
dehydration on hyperthermia during exercise in the heat and the
mechanisms contributing to the dehydration-mediated stroke volume (SV)
reduction. Fifteen endurance-trained cyclists [maximal
O2 consumption
(
O2 max) = 4.5 l/min] exercised in the heat for 100-120 min and either became dehydrated by 4% body weight or remained euhydrated by drinking
fluids. Measurements were made after they continued exercise at 71%
O2 max for 30 min
while 1) euhydrated with an
esophageal temperature (Tes) of
38.1-38.3°C (control); 2)
euhydrated and hyperthermic (39.3°C);
3) dehydrated and hyperthermic with
skin temperature (Tsk) of
34°C; 4) dehydrated with
Tes of 38.1°C and Tsk of 21°C; and
5) condition
4 followed by restored blood volume. Compared with
control, hyperthermia (1°C Tes
increase) and dehydration (4% body weight loss) each separately
lowered SV 7-8% (11 ± 3 ml/beat;
P < 0.05) and increased heart rate
sufficiently to prevent significant declines in cardiac output.
However, when dehydration was superimposed on hyperthermia, the
reductions in SV were significantly (P < 0.05) greater (26 ± 3 ml/beat), and cardiac output declined 13% (2.8 ± 0.3 l/min). Furthermore, mean arterial
pressure declined 5 ± 2%, and systemic vascular resistance
increased 10 ± 3% (both P < 0.05). When hyperthermia was
prevented, all of the decline in SV with dehydration was due to reduced
blood volume (~200 ml). These results demonstrate that the
superimposition of dehydration on hyperthermia during exercise in the
heat causes an inability to maintain cardiac output and blood pressure
that makes the dehydrated athlete less able to cope with hyperthermia.
cardiovascular strain; stroke volume; cardiac output; blood pressure
This article has been cited by other articles:
|
|
 |
|
  A. Lucia, C. Foster, P.-M. Lepretre, E. Henriksen, M. Sundstedt, P. Hedberg, C. A. Vella, R. A. Robergs, E. F. Coyle, J. D. Trinity, et al. Stroke volume does/does not decline during exercise at maximal effort in healthy individuals J Appl Physiol, January 1, 2008; 104(1): 281 - 283. [Full Text] [PDF]
|
|
|
|
 |
|
 J. Gonzalez-Alonso, C. G. Crandall, and J. M. Johnson The cardiovascular challenge of exercising in the heat J. Physiol., January 1, 2008; 586(1): 45 - 53. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Fernandez-Fernandez, A. Mendez-Villanueva, B. Fernandez-Garcia, and N. Terrados Match activity and physiological responses during a junior female singles tennis tournament Br. J. Sports Med., November 1, 2007; 41(11): 711 - 716. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B Murray Manufactured arguments: turning consensus into controversy does not advance science Br. J. Sports Med., February 1, 2007; 41(2): 106 - 107. [Full Text] [PDF]
|
|
|
|
|
|
M F Bergeron, J L Waller, and E L Marinik Voluntary fluid intake and core temperature responses in adolescent tennis players: sports beverage versus water. Br. J. Sports Med., May 1, 2006; 40(5): 406 - 410. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. A. Kavouras, L. E. Armstrong, C. M. Maresh, D. J. Casa, J. A. Herrera-Soto, T. P. Scheett, J. Stoppani, G. W. Mack, and W. J. Kraemer Rehydration with glycerol: endocrine, cardiovascular, and thermoregulatory responses during exercise in the heat J Appl Physiol, February 1, 2006; 100(2): 442 - 450. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G Slater, A J Rice, R Tanner, K Sharpe, C J Gore, D G Jenkins, and A G Hahn Acute weight loss followed by an aggressive nutritional recovery strategy has little impact on on-water rowing performance Br. J. Sports Med., January 1, 2006; 40(1): 55 - 59. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. N. Cheuvront, R. Carter III, J. W. Castellani, and M. N. Sawka Hypohydration impairs endurance exercise performance in temperate but not cold air J Appl Physiol, November 1, 2005; 99(5): 1972 - 1976. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Low, A. Purvis, T. Reilly, and N. T. Cable The prolactin responses to active and passive heating in man Exp Physiol, November 1, 2005; 90(6): 909 - 917. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y.-I. Kamijo, T. Okumoto, Y. Takeno, K. Okazaki, M. Inaki, S. Masuki, and H. Nose Transient cutaneous vasodilatation and hypotension after drinking in dehydrated and exercising men J. Physiol., October 15, 2005; 568(2): 689 - 698. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. P Mortensen, E. A Dawson, C. C Yoshiga, M. K Dalsgaard, R. Damsgaard, N. H Secher, and J. Gonzalez-Alonso Limitations to systemic and locomotor limb muscle oxygen delivery and uptake during maximal exercise in humans J. Physiol., July 1, 2005; 566(1): 273 - 285. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A I Da Silva and R Fernandez Dehydration of football referees during a match Br. J. Sports Med., December 1, 2003; 37(6): 502 - 506. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Nybo, T. Jensen, B. Nielsen, and J. Gonzalez-Alonso Effects of marked hyperthermia with and without dehydration on {V}O2 kinetics during intense exercise J Appl Physiol, March 1, 2001; 90(3): 1057 - 1064. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. D. Roy, H. J. Green, and M. Burnett Prolonged exercise after diuretic-induced hypohydration: effects on substrate turnover and oxidation Am J Physiol Endocrinol Metab, December 1, 2000; 279(6): E1383 - E1390. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. F Coyle Physical activity as a metabolic stressor Am. J. Clinical Nutrition, August 1, 2000; 72(2): 512S - 520. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. G. Fritzsche, T. W. Switzer, B. J. Hodgkinson, S.-H. Lee, J. C. Martin, and E. F. Coyle Water and carbohydrate ingestion during prolonged exercise increase maximal neuromuscular power J Appl Physiol, February 1, 2000; 88(2): 730 - 737. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Gonzalez-Alonso, R. Mora-Rodriguez, and E. F. Coyle Stroke volume during exercise: interaction of environment and hydration Am J Physiol Heart Circ Physiol, February 1, 2000; 278(2): H321 - H330. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Gonzalez-Alonso, R. Mora-Rodriguez, and E. F. Coyle Supine exercise restores arterial blood pressure and skin blood flow despite dehydration and hyperthermia Am J Physiol Heart Circ Physiol, August 1, 1999; 277(2): H576 - H583. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Gonzalez-Alonso, C. Teller, S. L. Andersen, F. B. Jensen, T. Hyldig, and B. Nielsen Influence of body temperature on the development of fatigue during prolonged exercise in the heat J Appl Physiol, March 1, 1999; 86(3): 1032 - 1039. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. J. Geor and L. J. McCutcheon Hydration effects on physiological strain of horses during exercise-heat stress J Appl Physiol, June 1, 1998; 84(6): 2042 - 2051. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
