Effect of priming exercise and body position on pulmonary oxygen uptake and muscle deoxygenation kinetics during cycle exercise

Goulding, Richie P and Marwood, Simon and Okushima, Dai and Poole, David and Barstow, Thomas and Lei, Tze-Huan and Kondon, Narihiko and Koga, Shunsaku (2020) Effect of priming exercise and body position on pulmonary oxygen uptake and muscle deoxygenation kinetics during cycle exercise. Journal of Applied Physiology, 129 (4). pp. 810-822. ISSN 8750-7587

	Text Revised CLEAN - Effect of priming exercise and body position on pulmonary oxygen uptake and muscle deoxygenation kinetics.docx - Accepted Version Download (180kB)
	Text Figure 1.docx - Accepted Version Download (230kB)
	Text Figure 2.docx - Accepted Version Download (151kB)
	Text Figure 3.docx - Accepted Version Download (154kB)
	Text Figure 4.docx - Accepted Version Download (115kB)
	Text Figure 5.docx - Accepted Version Download (114kB)
	Text Figure 6.docx - Accepted Version Download (48kB)
	Text Table 1 (1).docx - Accepted Version Download (15kB)
	Text Table 2 (1).docx - Accepted Version Download (14kB)
	Text Table 3 (1).docx - Accepted Version Download (14kB)
	Text Table 4 (1).docx - Accepted Version Download (15kB)
	Text Table 5.docx - Accepted Version Download (14kB)

Abstract

We hypothesized that the performance of prior heavy exercise would speed pulmonary oxygen uptake (V ̇O2) kinetics (i.e. described by a time constant, τ_V ̇ O2) and reduce the amplitude of muscle deoxygenation (deoxy[heme]) kinetics in the supine (S) but not upright (U) body positions. 17 healthy men completed heavy intensity constant work rate exercise tests in S and U consisting of two bouts of 6 min cycling separated by 6 min cycling at 20 W. Pulmonary V ̇O2 was measured breath-by-breath; total- and deoxy[heme] were determined via time-resolved-NIRS at three muscle sites. Priming exercise reduced τ_V ̇ O2 in S (bout 1: 36 ± 10 vs. bout 2: 28 ± 10 s, P < 0.05) but not U (bout 1: 27 ± 8 vs. bout 2: 25 ± 7 s, P > 0.05). The deoxy[heme] amplitude was increased following priming in S (bout 1: 25-28 vs. bout 2: 30-35 μM, P < 0.05) but not U (bout 1: 13-18 vs. bout 2: 17-25 μM, P > 0.05), whereas baseline total[heme] was enhanced in S (bout 1: 110-179 vs. bout 2: 128-185 μM, P < 0.05) and U (bout 1: 123-186 vs. bout 2: 137-197 μM, P < 0.05). Priming exercise increased total[heme] in both S and U, likely indicating enhanced diffusive O2 delivery. However, the observation that following priming the amplitude of the deoxy[heme] response was increased in S suggests that the reduction in τ_V ̇ O2 subsequent to priming was related to a combination of both enhanced intracellular O2 utilization and increased O2 delivery.

Item Type:	Article
Additional Information and Comments:	Copyright © 2020 the American Physiological Society. This is the author's version of an article that was accepted for publication in the Journal of Applied Physiology. The final, published version is available from: https://journals.physiology.org/doi/abs/10.1152/japplphysiol.00478.2020
Keywords:	near-infrared spectroscopy, oxygen delivery, oxygen utilization, priming exercise, oxygen uptake kinetics
Faculty / Department:	Faculty of Human and Digital Sciences > School of Health and Sport Sciences
Depositing User:	Simon Marwood
Date Deposited:	18 Nov 2020 09:43
Last Modified:	18 Nov 2020 09:49
URI:	https://hira.hope.ac.uk/id/eprint/3177

Actions (login required)

View Item