The Influence of Acute Hypoxia on Oxygen Uptake and Muscle Oxygenation Kinetics During Cycling Exercise in Prepubertal Boys.

IF 1.4 4区医学 Q3 PEDIATRICS Pediatric Exercise Science Pub Date : 2024-06-26 DOI:10.1123/pes.2023-0089

Max E Weston, Neil Armstrong, Bert Bond, Owen W Tomlinson, Craig A Williams, Alan R Barker

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Abstract

Purpose: To examine the effect of normobaric hypoxia on pulmonary oxygen uptake (V˙O2) and muscle oxygenation kinetics during incremental and moderate-intensity exercise in children.

Methods: Eight prepubertal boys (9-11 y) performed incremental cycle tests to exhaustion in both normoxia and hypoxia (fraction of inspired O2 of 15%) followed by repeat 6-minute transitions of moderate-intensity exercise in each condition over subsequent visits.

Results: Maximal oxygen uptake (V˙O2max) was reduced in hypoxia compared with normoxia (1.69 [0.20] vs 1.87 [0.26] L·min-1, P = .028), although the gas exchange threshold was not altered in absolute terms (P = .33) or relative to V˙O2max (P = .78). During moderate-intensity exercise, the phase II V˙O2 time constant (τ) was increased in hypoxia (18 [9] vs 24 [8] s, P = .025), with deoxyhemoglobin τ unchanged (17 [8] vs 16 [6], P ≥ .28).

Conclusions: In prepubertal boys, hypoxia reduced V˙O2max and slowed V˙O2 phase II kinetics during moderate-intensity exercise, despite unchanged deoxyhemoglobin kinetics. These data suggest an oxygen delivery dependence of V˙O2max and moderate-intensity V˙O2 kinetics under conditions of reduced oxygen availability in prepubertal boys.

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急性缺氧对青春期前男孩自行车运动中摄氧率和肌肉氧合动力学的影响

目的：研究常压低氧对儿童进行增量和中等强度运动时肺氧摄氧量（V˙O2）和肌肉氧合动力学的影响：方法：8 名青春期前的男孩（9-11 岁）在常氧和缺氧（吸入氧气分数为 15%）条件下进行增量循环测试，直至力竭，然后在随后的访问中在每种条件下重复进行 6 分钟的中等强度运动：结果：与常氧状态相比，低氧状态下的最大摄氧量（V˙O2max）有所降低（1.69 [0.20] vs 1.87 [0.26] L-min-1，P = .028），但气体交换阈值的绝对值（P = .33）或相对于 V˙O2max（P = .78）均无变化。在中等强度的运动中，第二阶段 V˙O2时间常数（τ）在缺氧时增加（18 [9] vs 24 [8] s，P = .025），脱氧血红蛋白τ不变（17 [8] vs 16 [6]，P ≥ .28）：结论：在青春期前的男孩中，尽管脱氧血红蛋白动力学不变，但缺氧会降低中等强度运动的 V˙O2max，减慢 V˙O2二期动力学。这些数据表明，在氧供应减少的条件下，青春期前男孩的V˙O2max和中等强度V˙O2动力学与氧输送有关。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Pediatric Exercise Science 医学-生理学

CiteScore

2.80

自引率

0.00%

发文量

审稿时长

>12 weeks

期刊介绍： Pediatric Exercise Science is a journal committed to enriching the scientific knowledge of exercise during childhood and adolescence. To this end it publishes information that contributes to an understanding of (a) the unique aspects of the physiologic, physical, biochemical, and psychologic responses of children to exercise, (b) the role of exercise in the treatment of pediatric chronic diseases, (c) the importance of physical activity in the prevention of illness and preservation of wellness, and (d) the means by which participation in sports may be made safer and more enjoyable for children and youth. Consideration will be given for publication of work by various methodologies consistent with the scientific approach. Besides original research, the journal includes review articles, abstracts from other journals, book reviews, and editorial comments. Pediatric Exercise Science encourages the expression of conflicting opinions regarding children and exercise by providing a forum for alternative viewpoints. At the same time it serves as a means of accumulating a base of research information that will allow application of experimental data to clinical practice. The scientific disciplines contributing to this body of knowledge are diverse. Therefore it is the purpose of this journal to provide a common focus for disseminating advances in the science of exercise during childhood. In doing so, the journal allows the opportunity for cross-fertilization of ideas between disciplines that will potentiate the growth of knowledge in this field. Pediatric Exercise Science seeks to stimulate new ideas regarding exercise in children and to increase the awareness of scientists, health care providers, and physical educators of the importance of exercise during childhood.