Alveolar Oxygen Uptake and Blood Flow Dynamics in Knee Extension Ergometry

R. L. Hughson; M. J. MacDonald; J. K. Shoemaker; C. Borkhoff

doi:10.1055/s-0038-1636847

Methods of Information in Medicine, Table of Contents

Methods Inf Med 1997; 36(04/05): 364-367
DOI: 10.1055/s-0038-1636847

Original Article

Schattauer GmbH

Alveolar Oxygen Uptake and Blood Flow Dynamics in Knee Extension Ergometry

R. L. Hughson

¹Department of Kinesiology, University of Waterloo, Waterloo, Canada

,

M. J. MacDonald

¹Department of Kinesiology, University of Waterloo, Waterloo, Canada

,

J. K. Shoemaker

¹Department of Kinesiology, University of Waterloo, Waterloo, Canada

,

C. Borkhoff

¹Department of Kinesiology, University of Waterloo, Waterloo, Canada

› Author Affiliations

Abstract

Abstract:

The relationship was studied between the increase in oxygen uptake (VO₂) measured breath-by-breath at the mouth, and the increase in femoral artery blood flow measured continuously with pulsed and echo Doppler methods. Five men exercised at 50 W on a knee extension ergometer in both the supine and the upright posture. The kinetics of the responses were determined by curve fitting to obtain the mean response time (MRT = 63% of the time required to achieve steady state). In the upright position, the increase in blood flow (MRT = 12.4 ± 9.4 s, mean ± SD) was faster than the increase in VO₂ (29.6 ± 9.3 s). Likewise in the supine position, blood flow increased more rapidly (25.1 + 9.7 s vs. 36.7 ± 9.6 s). It should be noted that the increase in blood flow appeared to be faster than VO₂, yet when blood flow adapted more slowly in the supine posture, it had an impact on the adaptation of VO₂. This suggests that blood flow might have important effects on metabolism at the onset of submaximal exercise.

Keywords:

Oxygen Uptake - Exercise - Breath-by-Breath Gas Exchange - Pulsed Doppler - Echo Doppler

Full Text

References

REFERENCES
1 Hughson RL. Exploring cardiorespiratory control mechanisms through gas exchange dynamics. Med Sei Sports Exerc 1990; 22: 72-9.
2 Yoshida T, Whipp BJ. Dynamic asymmetries of cardiac output transients in response to muscular exercise in man. J Physiol (Lond) 1994; 480: 355-9.
3 Barstow TJ, Buchthal S, Zanconato S, Cooper DM. Muscle energetics and pulmonary oxygen uptake kinetics during moderate exercise. J Appl Physiol 1994; 77: 1742-9.
4 Hughson RL, Cochrane JE, Butler GC. Faster O₂ uptake kinetics at onset of supine exercise with than without lower body negative pressure. J Appl Physiol 1993; 75: 1962-7.
5 Shoemaker JK, Naylor HL, Pozeg ZI, Hughson RL. Failure of prostaglandins to modulate the time course of blood flow during dynamic forearm exercise in humans. J Appl Physiol 1996; 81: 1516-21.
6 Tschakovsky ME, Shoemaker JK, Hughson RL. Vasodilation and muscle pump contribution to immediate exercise hyperemia. Am J Physiol Heart Circ Physiol 1996; 271: H1697-H1701.
7 Shoemaker JK, Pozeg ZI, Hughson RL. Forearm blood flow by Doppler ultrasound during rest and exercise: tests of day-to-dayrepeatability. Med Sei Sports Exerc 1996; 28: 1144-9.
8 Hughson RL, Shoemaker JK, Tschakovsky M, Kowalchuk JM. Dependence of muscle VO₂ on blood flow dynamics at the onset of forearm exercise. J Appl Physiol 1996; 81: 1619-26.
9 Shoemaker JK, Hodge L, Hughson RL. Cardiorespiratory kinetics and femoral artery blood velocity during dynamic knee extension exercise. J Appl Physiol 1994; 77: 2625-32.
10 Shoemaker JK, Phillips SM, Green HJ, Hughson RL. Faster femoral artery blood velocity kinetics at the onset of exercise following short-term training. Cardiovasc Res 1996; 31: 278-86.
11 Kagaya A, Ogita F. Blood flow during muscle contraction and relaxation in rhythmic exercise at different intensities. Ann Physiol Anthrop 1992; 11: 251-6.
12 Sorensen KE, Celermajer DS, Spiegelhalter DJ, Georgakopoulos D, Robertson J, Thomas O. et al. Non-invasive measurement of human endothelium dependent arterial responses: accuracy and reproducibility. Br Heart J 1995; 74: 247-53.
13 Sheriff DD, Rowell LB, Scher AM. Is rapid rise in vascular conductance at onset of dynamic exercise due to muscle pump. Am J Physiol Heart Circ Physiol 1993; 265: H1227-34.
14 Corcondilas A, Koroxenidis GT, Shepherd JT. Effect of a brief contraction of forearm muscles on forearm blood flow. J Appl Physiol 1964; 19: 142-6.
15 Tschakovsky ME, Shoemaker JK, Hughson RL. Beat-by-beat forearm blood flow with Doppler ultrasound and strain-gauge plethysmography. J Appl Physiol 1995; 79: 713-9.
16 Segal SS. Cell-to-cell communication coordinates blood flow control. Hypertension 1994; 23: 1113-20.
17 Gayeski TEJ, Connett RJ, Honig CR. Minimum intracellular PO₂ for maximum cytochrome turnover in red muscle in situ. Am J Physiol 1987; 252: H906-15.
18 Connett RJ, Honig CR, Gayeski TEJ, Brooks GA. Defining hypoxia: A systems view of VO₂, glycolysis, energetics, and intracellular PO₂ . J Appl Physiol 1990; 68: 833-42.
19 Wilson DF. Factors affecting the rate and energetics of mitochondrial oxidative phosphorylation. Med Sei Sports Exerc 1994; 26: 37-43.
20 Arthur PG, Hogan MC, Bebout DE, Wagner PD, Hochachka PW. Modeling the effects of hypoxia on ATP turnover in exercising muscle. J Appl Physiol 1992; 73: 737-42.
21 Hogan MC, Nioka S, Brechue WF, Chance B. A ³¹P-NMR study of tissue respiration in working dog muscle during reduced O₂ delivery conditions. J Appl Physiol 1992; 73: 1662-70.
22 Grassi B, Poole DC, Richardson RS, Knight DR, Erickson BK, Wagner PD. Muscle O₂ uptake kinetics in humans: implications for metabolic control. J Appl Physiol 1996; 80: 988-98.