A Brief History of Pediatric Exercise Physiology

Bull. World Health Organ.

2019

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Rigorously determined peak oxygen uptake is internationally recognized as the criterion measure of youth cardiorespiratory fitness. The assessment and interpretation of children’s and adolescents’ peak oxygen uptake and the relationship of the measure with other health-related variables are well documented. There has been a recent resurgence of interest in the prediction of peak oxygen uptake from field performance tests in young people. However, coupled with ratio-scaling of data and the raising of clinical red flags, these practices risk clouding our understanding of youth cardiorespiratory fitness and its relationship with current and future health. We believe these methods have the potential to mislead clinical practice and misguide recommendations for the promotion of youth cardiovascular health. We discuss relevant scientific evidence and interpretations that have emerged from predicting youth cardiorespiratory fitness from performance test scores. We argue that children deserve to have health care founded on evidence-based science and not on myths and misconceptions.

Section: Evidence Basementioning

confidence: 99%

Youth cardiorespiratory fitness: evidence, myths and misconceptions

Bull. World Health Organ.

2019

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“…Peak oxygen uptake ( V O 2 ), the highest V O 2 elicited during an incremental exercise test to exhaustion, is internationally recognized as the 'gold standard' measure of youth cardiorespiratory fitness. Peak V O 2 is probably the most researched physiological variable in paediatric exercise science (Falk et al 2018), but the vast majority of investigations have been cross-sectional with data analyses Communicated by I. Mark Olfert. clouded by inappropriate ratio scaling of peak V O 2 with body mass (BM) and interpretation of youth peak V O 2 in mL kg −1 min −1 (Welsman and Armstrong 2019).…”

Section: Introductionmentioning

confidence: 99%

Multilevel allometric modelling of maximum cardiac output, maximum arteriovenous oxygen difference, and peak oxygen uptake in 11–13-year-olds

2020

Eur J Appl Physiol

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Purposes To investigate longitudinally (1) the contribution of morphological covariates to explaining the development of maximum cardiac output (Q max) and maximum arteriovenous oxygen difference (a-vO 2 diff max), (2) sex differences in Q max and a-vO 2 diff max once age, maturity status, and morphological covariates have been controlled for, and, (3) the contribution of concurrent changes in morphological and cardiovascular covariates to explaining the sex-specific development of peak oxygen uptake (V O 2). Methods Fifty-one (32 boys) 11-13-year-olds had their peak V O 2 , maximum heart rate (HR max), Q max, and a-vO 2 diff max determined during treadmill running on three annual occasions. The data were analysed using multilevel allometric modelling. Results There were no sex differences in HR max which was not significantly (p > 0.05) correlated with age, morphological variables, or peak V O 2. The best-fit models for Q max and a-vO 2 diff max were with fat-free mass (FFM) as covariate with age, maturity status, and haemoglobin concentration not significant (p > 0.05). FFM was the dominant influence on the development of peak V O 2. With FFM controlled for, the introduction of either Q max or a-vO 2 diff max to multilevel models of peak V O 2 resulted in significant (p < 0.05) additional contributions to explaining the sex difference. Conclusions (1) With FFM controlled for, there were no sex differences in Q max or a-vO 2 diff max, (2) FFM was the dominant influence on the development of peak V O 2 , and (3) with FFM and either Q max or a-vO 2 diff max controlled for, there remained an unresolved sex difference of ~ 4% in peak V O 2 .

“…Although it is recognized that other variables contribute to aerobic fitness [2,9] herein we will focus on peak VO 2 and use the terms peak VO 2 and aerobic fitness synonymously. Peak VO 2 is the most researched physiological variable in paediatric exercise physiology [36], but traditional data analyses have clouded understanding of its development in relation to growth and maturation and misled comparisons of aerobic fitness both within and between youth sports [3].…”

Section: Aerobic Fitnessmentioning

confidence: 99%

The Development of Aerobic and Anaerobic Fitness with Reference to Youth Athletes

J. of SCI. IN SPORT AND EXERCISE

2020

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Purpose To challenge current conventions in paediatric sport science and use data from recent longitudinal studies to elucidate the development of aerobic and anaerobic fitness, with reference to youth athletes. Methods (1) To critically review the traditional practice of ratio scaling physiological variables with body mass and, (2) to use multiplicative allometric models of longitudinal data, founded on 1053 (550 from boys) determinations of 10-17-yearolds' peak oxygen uptake (VO 2) and 763 (405 from boys) determinations of 11-17-year-olds' peak power output (PP) and mean power output (MP), to investigate the development of aerobic and anaerobic fitness in youth. Results The statistical assumptions underpinning ratio scaling of physiological variables in youth are seldom met. Multiplicative allometric modelling of longitudinal data has demonstrated that fat free mass (FFM) acting as a surrogate for active muscle mass, is the most powerful morphological influence on PP, MP, and peak VO 2. With FFM appropriately controlled for, age effects remain significant but additional, independent effects of maturity status on anaerobic and aerobic fitness are negated. Conclusions Ratio scaling of physiological variables with body mass is fallacious, confounds interpretation of the development of anaerobic and aerobic fitness, and misleads fitness comparisons within and across youth sports. Rigorous evaluation of the development of anaerobic and aerobic fitness in youth requires longitudinal analyses of sex-specific, concurrent changes in age-and maturation-driven morphological covariates. Age and maturation-driven changes in FFM are essential considerations when evaluating the physiological development of youth athletes.