HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Free Full Text (PDF) Free All Versions of this Article: 99/4/1462    most recent 00173.2005v1 Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (7) Citing Articles via Google Scholar Google Scholar Articles by Paterson, N. D. Articles by Paterson, D. H. Search for Related Content PubMed PubMed Citation Articles by Paterson, N. D. Articles by Paterson, D. H.

Effects of prior heavy-intensity exercise during single-leg knee extension on O₂ kinetics and limb blood flow

¹Canadian Centre for Activity and Aging, ²School of Kinesiology, and ³Department of Physiology and Pharmacology, The University of Western Ontario, London, Canada

Submitted 10 February 2005 ; accepted in final form 9 May 2005

The effects of prior heavy-intensity exercise on O₂ uptake (O₂) kinetics of a second heavy exercise may be due to vasodilation (associated with metabolic acidosis) and improved muscle blood flow. This study examined the effect of prior heavy-intensity exercise on femoral artery blood flow (Qleg) and its relationship with O₂ kinetics. Five young subjects completed five to eight repeats of two 6-min bouts of heavy-intensity one-legged, knee-extension exercise separated by 6 min of loadless exercise. O₂ was measured breath by breath. Pulsed-wave Doppler ultrasound was used to measure Qleg. O₂ and blood flow velocity data were fit using a monoexponential model to identify phase II and phase III time periods and estimate the response amplitudes and time constants (). Phase II O₂ kinetics was speeded on the second heavy-intensity exercise [mean (SD), 29 (10) s to 24 (10) s, P < 0.05] with no change in the phase II (or phase III) amplitude. Qleg was elevated before the second exercise [1.55 (0.34) l/min to 1.90 (0.25) l/min, P < 0.05], but the amplitude and time course [, 25 (13) s to 35 (13) s] were not changed, such that throughout the transient the Qleg (and Qleg/O₂) did not differ from the prior heavy exercise. Thus O₂ kinetics were accelerated on the second exercise, but the faster kinetics were not associated with changes in Qleg. Thus limb blood flow appears not to limit O₂ kinetics during single-leg heavy-intensity exercise nor to be the mechanism of the altered O₂ response after heavy-intensity prior exercise.

femoral artery blood flow; priming exercise; oxygen uptake; primary component O₂ kinetics

This article has been cited by other articles:

				S. Koga, D. C. Poole, L. F. Ferreira, B. J. Whipp, N. Kondo, T. Saitoh, E. Ohmae, and T. J. Barstow Spatial heterogeneity of quadriceps muscle deoxygenation kinetics during cycle exercise J Appl Physiol, December 1, 2007; 103(6): 2049 - 2056. [Abstract] [Full Text] [PDF]

				D. S. DeLorey, J. M. Kowalchuk, A. P. Heenan, G. R. duManoir, and D. H. Paterson Prior exercise speeds pulmonary O2 uptake kinetics by increases in both local muscle O2 availability and O2 utilization J Appl Physiol, September 1, 2007; 103(3): 771 - 778. [Abstract] [Full Text] [PDF]

				G. H. Raymer, S. C. Forbes, J. M. Kowalchuk, R. T. Thompson, and G. D. Marsh Prior exercise delays the onset of acidosis during incremental exercise J Appl Physiol, May 1, 2007; 102(5): 1799 - 1805. [Abstract] [Full Text] [PDF]

				B. J. Gurd, S. J. Peters, G. J. F. Heigenhauser, P. J. LeBlanc, T. J. Doherty, D. H. Paterson, and J. M. Kowalchuk Prior heavy exercise elevates pyruvate dehydrogenase activity and speeds O2 uptake kinetics during subsequent moderate-intensity exercise in healthy young adults J. Physiol., December 15, 2006; 577(3): 985 - 996. [Abstract] [Full Text] [PDF]

				A. M. Jones, N. J. A. Berger, D. P. Wilkerson, and C. L. Roberts Effects of "priming" exercise on pulmonary O2 uptake and muscle deoxygenation kinetics during heavy-intensity cycle exercise in the supine and upright positions J Appl Physiol, November 1, 2006; 101(5): 1432 - 1441. [Abstract] [Full Text] [PDF]