Hyperoxia speeds pulmonary oxygen uptake kinetics and increases critical power during supine cycling

Goulding, Richie P.; Roche, Denise M.; Marwood, Simon

doi:10.1113/ep087599

Cited by 18 publications

(37 citation statements)

References 49 publications

(112 reference statements)

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“…Furthermore, in a recent study we demonstrated that hyperoxia speeded pulmonary O 2 kinetics and increased CP during supine exercise, but that the change in ! O2 did not correlate linearly with the change in CP (9). Taken together, the relative, independent contributions of !…”

Section: Introductionmentioning

confidence: 80%

“…[HbO + MbO 2 ] was increased during both moderate (hyperoxia: 74 ± 21 µM, normoxia: ± 18; main effect of condition, P < 0.001, Figure 4A) and severe (hyperoxia: 73 ± 20 µM, normoxia: 66 ± 15; main effect of condition, P = 0.039, Figure 4B) Figure 3A) or severe exercise ( Figure 3B, kinetics increases CP (7,9), and also that a slowing of the O 2 kinetics decreases CP (6,8).…”

Section: Methodsmentioning

confidence: 96%

“…Specifically, when ! O2 was acutely reduced, CP increased (7,9), whereas when ! O2 was acutely increased, CP correspondingly decreased (6,8).…”

Section: Introductionmentioning

confidence: 95%

“…However, hyperoxia does not appear to speed the pulmonary O 2 kinetics during upright cycling (13)(14)(15), which is seemingly inconsistent with the putative linkage between ! O2 and CP previously described (6)(7)(8)(9). Nevertheless, Vanhatalo et al (16) previously demonstrated that CP was increased when determined in hyperoxia compared to normoxia, suggesting a central role for O 2 availability per se in determining CP.…”

Section: Introductionmentioning

confidence: 96%

“…We have recently provided evidence to suggest that ! O2 is an independent determinant of CP (6)(7)(8)(9). Specifically, when !…”

Section: Introductionmentioning

confidence: 99%

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Effect of Hyperoxia on Critical Power and V˙O2 Kinetics during Upright Cycling

Goulding

Roche

Marwood

2019

Medicine &Amp; Science in Sports &Amp; Exercise

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Introduction/Purpose: Critical power (CP) is a fundamental parameter defining highintensity exercise tolerance, however its physiological determinants are incompletely understood. The present study determined the impact of hyperoxia on CP, the time constant of phase II pulmonary oxygen uptake kinetics (! O2), and muscle oxygenation (assessed by near-infrared spectroscopy) in 9 healthy men performing upright cycle ergometry. Methods: CP was determined in normoxia and hyperoxia (fraction of inspired O 2 = 0.5) via 4 severeintensity constant load exercise tests to exhaustion on a cycle ergometer, repeated once in each condition. During each test, ! O2 and the time constant of muscle deoxyhaemoglobin kinetics (τ [HHb]), alongside absolute concentrations of muscle oxyhaemoglobin ([HbO 2 ]), were determined. Results: CP was greater (hyperoxia: 216 ± 30 vs. normoxia: 197 ± 29W; P < 0.001) whereas W' was reduced (hyperoxia: 15.4 ± 5.2 kJ, normoxia: 17.5 ± 4.3 W; P = 0.037) in hyperoxia compared to normoxia. ! O2 (hyperoxia: 35 ± 12 vs normoxia: 33 ± 10 s; P = 0.33) and τ [HHb] (hyperoxia: 11 ± 5 vs. normoxia: 14 ± 5 s; P = 0.65) were unchanged between conditions, whereas [HbO 2 ] during exercise was greater in hyperoxia compared to normoxia (hyperoxia: 73 ± 20 vs. normoxia: 66 ± 15 µM; P = 0.001). Conclusion: This study provides novel insights into the physiological determinants of CP and by extension, exercise tolerance. Microvascular oxygenation and CP were improved during exercise in hyperoxia compared with normoxia. Importantly, the improved microvascular oxygenation afforded by hyperoxia did not alter ! O2 , suggesting that microvascular O 2 availability is an independent determinant of the upper limit for steady-state exercise, i.e. CP.

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Section: Introductionmentioning

confidence: 80%

Section: Methodsmentioning

confidence: 96%

“…Specifically, when ! O2 was acutely reduced, CP increased (7,9), whereas when ! O2 was acutely increased, CP correspondingly decreased (6,8).…”

Section: Introductionmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 96%

“…We have recently provided evidence to suggest that ! O2 is an independent determinant of CP (6)(7)(8)(9). Specifically, when !…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Effect of Hyperoxia on Critical Power and V˙O2 Kinetics during Upright Cycling

Goulding

Roche

Marwood

2019

Medicine &Amp; Science in Sports &Amp; Exercise

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Exceeding a “critical” muscle Pi: implications for $$\dot{\text{V}}\text{O}_{2}$$ and metabolite slow components, muscle fatigue and the power–duration relationship

Korzeniewski¹,

Rossiter

2020

Eur J Appl Physiol

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Impact of supine versus upright exercise on muscle deoxygenation heterogeneity during ramp incremental cycling is site specific

et al. 2021

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Purpose We tested the hypothesis that incremental ramp cycling exercise performed in the supine position (S) would be associated with an increased reliance on muscle deoxygenation (deoxy[heme]) in the deep and superficial vastus lateralis (VLd and VLs, respectively) and the superficial rectus femoris (RFs) when compared to the upright position (U). Methods 11 healthy men completed ramp incremental exercise tests in S and U. Pulmonary $$\dot{V}$$ V ˙ O2 was measured breath-by-breath; deoxy[heme] was determined via time-resolved near-infrared spectroscopy in the VLd, VLs and RFs. Results Supine exercise increased the overall change in deoxy[heme] from baseline to maximal exercise in the VLs (S: 38 ± 23 vs. U: 26 ± 15 μM, P < 0.001) and RFs (S: 36 ± 21 vs. U: 25 ± 15 μM, P < 0.001), but not in the VLd (S: 32 ± 23 vs. U: 29 ± 26 μM, P > 0.05). Conclusions The present study supports that the impaired balance between O2 delivery and O2 utilization observed during supine exercise is a regional phenomenon within superficial muscles. Thus, deep muscle defended its O2 delivery/utilization balance against the supine-induced reductions in perfusion pressure. The differential responses of these muscle regions may be explained by a regional heterogeneity of vascular and metabolic control properties, perhaps related to fiber type composition.

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Hyperoxia speeds pulmonary oxygen uptake kinetics and increases critical power during supine cycling

Cited by 18 publications

References 49 publications

Effect of Hyperoxia on Critical Power and V˙O2 Kinetics during Upright Cycling

Effect of Hyperoxia on Critical Power and V˙O2 Kinetics during Upright Cycling

Exceeding a “critical” muscle Pi: implications for $$\dot{\text{V}}\text{O}_{2}$$ and metabolite slow components, muscle fatigue and the power–duration relationship

Impact of supine versus upright exercise on muscle deoxygenation heterogeneity during ramp incremental cycling is site specific

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