Cardio-respiratory and muscle oxygenation responses to submaximal and maximal exercise in normobaric hypoxia : comparison between children and adults

Ušaj, Anton (author), Sotiridis, Alexandros (author), Debevec, Tadej (author)

As differential physiological responses to hypoxic exercise between adults and children remain poorly understood, we aimed to comprehensively characterise cardiorespiratory and muscle oxygenation responses to submaximal and maximal exercise in normobaric hypoxia between the two groups. Following familiarisation, fifteen children (Age = 9 ± 1 years) and fifteen adults (Age = 22 ± 2 years) completed two graded cycling exercise sessions to exhaustion in a randomized and single-blind manner in normoxia (NOR; F$_i$O$_2$ = 20.9) and normobaric hypoxia (HYP; F$_i$O$_2$ = 13.0) exercises conditions. Age-specific workload increments were 25 W·3 min$^{−1}$ for children and 40 W·3 min$^{−1}$ for adults. Gas exchange and vastus lateralis oxygenation parameters were measured continuously via metabolic cart and near-infrared spectroscopy, respectively. Hypoxia provoked significant decreases in maximal power output P$_{MAX}$ (children = 29%; adults 16% (F = 39.3; p < 0.01)) and power output at the gas exchange threshold (children = 10%; adults:18% (F = 8.08; p = 0.01)) in both groups. Comparable changes were noted in most respiratory and gas exchange parameters at similar power outputs between groups. Children, however, demonstrated, lower P$_{ET}$CO$_2$ throughout the test at similar power outputs and during the maintenance of $\dot{V}$CO$_2$ at the maximal power output. These data indicate that, while most cardiorespiratory responses to acute hypoxic exercise are comparable between children and adults, there exist age-related differential responses in select respiratory and muscle oxygenation parameters.

• Language: English
• Keywords: sport, hypoxemia, exercise, ventilation, muscle oxygenation, age, adults, children, maturation
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FŠ - Faculty of Sport
• Publication status: Published
• Publication version: Version of Record
• Year: 2023
• Number of pages: 14 str.
• Numbering: Vol. 12, iss. 3, art. 457
• PID: 20.500.12556/RUL-154050
• UDC: 796.01
• ISSN on article: 2079-7737
• DOI: 10.3390/biology12030457
• COBISS.SI-ID: 145498627
• Publication date in RUL: 22.01.2024

Record is a part of a journal

• Title: Biology
• Shortened title: Biology
• Publisher: MDPI
• ISSN: 2079-7737
• COBISS.SI-ID: 523004441

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: šport, hipoksemija, telovadba, vadba, prezračevanje, oksigenacija mišic, starost, odrasli, otroci, staranje