scholarly journals Oxygen cost of exercise hyperpnoea is greater in women compared with men

2015 ◽  
Vol 593 (8) ◽  
pp. 1965-1979 ◽  
Author(s):  
Paolo B. Dominelli ◽  
Jacqueline N. Render ◽  
Yannick Molgat-Seon ◽  
Glen E. Foster ◽  
Lee M. Romer ◽  
...  
Keyword(s):  
Oxygen Cost ◽  
Exercise Hyperpnoea

Predicting the oxygen cost of walking in hemiparetic stroke patients

2018 ◽  
Vol 61 (5) ◽  
pp. 309-314 ◽  
Author(s):  
M. Compagnat ◽  
S. Mandigout ◽  
D. Chaparro ◽  
J.Y. Salle ◽  
J.C. Daviet
Keyword(s):  
Oxygen Cost ◽  
Stroke Patients ◽  
Hemiparetic Stroke

scholarly journals Time dependence of the oxygen cost of force development during systole in the canine left ventricle.

1986 ◽  
Vol 59 (1) ◽  
pp. 27-38 ◽  
Author(s):  
R Teplick ◽  
G S Haas ◽  
E Trautman ◽  
J Titus ◽  
G Geffin ◽  
...  
Keyword(s):  
Left Ventricle ◽  
Time Dependence ◽  
Oxygen Cost ◽  
Force Development

Which method should be chosen to estimate the oxygen cost of walking in post-stroke individuals?

2021 ◽  
Author(s):  
Maxence Compagnat M ◽  
Stéphane Mandigout ◽  
Anaick Perrochon ◽  
Jean Yves Salle ◽  
Jean Christophe Daviet
Keyword(s):  
Oxygen Cost ◽  
Post Stroke

scholarly journals Impact of l-citrulline supplementation on oxygen uptake kinetics during walking

2018 ◽  
Vol 43 (6) ◽  
pp. 631-637 ◽  
Author(s):  
John Ashley ◽  
Youngdeok Kim ◽  
Joaquin U. Gonzales
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Oxygen Uptake ◽  
Oxygen Uptake Kinetics ◽  
Uptake Kinetics ◽  
Oxygen Deficit ◽  
Moderate Intensity ◽  
Oxygen Cost ◽  
Cohen’S D ◽  
Cohen's D

Supplementation with l-citrulline (Cit) has been shown to improve muscle oxygenation and oxygen uptake kinetics during moderate- to high-intensity cycling in young men. The aim of this study was to test the hypothesis that Cit would improve oxygen uptake kinetics during walking in older and young adults. In a randomized, double-blind study, 26 (15 women, 11 men) adults between the ages of 20–35 years (n = 15) and 64–86 years (n = 11) completed 7-day periods of taking placebo and Cit (6 g/day) in a crossover manner. Participants walked on a treadmill at 40% heart rate reserve while pulmonary oxygen uptake was measured using indirect calorimetry. Net oxygen cost, mean response time (MRT), and the oxygen deficit were calculated before and after each supplement period. There was no significant change (P > 0.05) in net oxygen cost, MRT, or the oxygen deficit after Cit in older adults, while young adults showed a decrease (P = 0.05) in the oxygen deficit after Cit that tended (P = 0.053) to be different than the change after placebo. Sex-stratified analysis revealed that Cit decreased MRT (P = 0.04, Cohen’s d = 0.41) and the oxygen deficit (P < 0.01, Cohen’s d = 0.56) in men with the change after Cit being greater than the change after placebo (MRT: −4.5 ± 2.1 vs. 3.4 ± 2.1 s, P = 0.01; deficit: −0.15 ± 0.05 vs. 0.01 ± 0.05 L, P = 0.02). All oxygen uptake parameters were unchanged (P > 0.05) following Cit and placebo in women. Cit does not alter the oxygen cost of moderate-intensity walking in young or older adults, but Cit improved the rate of rise in oxygen uptake at exercise onset in men.

Hypercapnic acidosis increases oxygen cost of contractility in the dog left ventricle

1994 ◽  
Vol 266 (2) ◽  
pp. H730-H740 ◽  
Author(s):  
K. Hata ◽  
Y. Goto ◽  
O. Kawaguchi ◽  
T. Takasago ◽  
A. Saeki ◽  
...  
Keyword(s):  
Mechanical Energy ◽  
Left Ventricular ◽  
Oxygen Cost ◽  
Membrane Oxygenator ◽  
Arterial Perfusion ◽  
Control Value ◽  
Arterial Blood ◽  
Total Mechanical Energy ◽  
Lv Volume ◽  
The Relationship

The effect of acidosis on left ventricular (LV) mechanoenergetics was assessed in seven excised, cross-circulated dog hearts with the use of the frameworks of the contractility index (Emax) and the relationship between myocardial oxygen consumption (VO2) and pressure-volume area (PVA; a measure of the LV total mechanical energy). Acidosis was stably maintained without hypoxia by appropriately mixing CO2 and air in a membrane oxygenator in the coronary arterial perfusion circuit. Acidosis [pH: 6.98 +/- 0.09 (SD), PCO2: 91 +/- 25 mmHg in the coronary arterial blood] decreased Emax by 45 +/- 12% (P < 0.01) and PVA by 47 +/- 12% (P < 0.01) at a fixed LV volume. When the preacidosis Emax level was restored by Ca2+ infusion during acidosis, unloaded VO2 (the VO2 intercept of the VO2-PVA relation) exceeded the control value by 19 +/- 17% (P < 0.05), indicating that acidosis required higher VO2 for nonmechanical activities at a matched Emax. Moreover, the oxygen cost of enhanced contractility (the incremental ratio of unloaded VO2 to Emax) was 1.53 +/- 0.40 times higher (P < 0.01) during acidosis than preacidosis. We conclude that acidosis results in LV contractile dysfunction accompanied by an increased oxygen cost of contractility. This increased energy cost of the excitation-contraction coupling can be accounted for by a decreased Ca2+ sensitivity of the contractile proteins during acidosis.

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