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

Abstract

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.

Editorial

“…In part I, this issue, Professors Armstrong and Welsman provide an excellent review that challenges current conventions surrounding the development of aerobic and anaerobic fitness in youth athletes [1]. This is followed by a systematic review from Pedley et al that reviews the utility of various kinetic and kinematic jumping and landing variable for predicting at heightened risk of injury [10].…”

Investigating the effect of sex, maturity, training status, and physical activity on performance and health-related parameters in children, adolescents, and adults

“…Exercise is strongly associated with numerous short-and long-term health-related parameters (Armstrong, 2007;Armstrong & Welsman, 2020c;Väistö et al, 2019).…”

“…The most researched parameter in paediatric exercise science is aerobic fitness and, specifically, peak oxygen uptake (V ̇O2) which is defined as the highest oxygen uptake that can be achieved despite further increases in work rate (Hill & Lupton, 1923). Peak V ̇O2 is the term most accepted within the paediatric literature due to the absence of a plateau in V ̇O2 in approximately 60 -80% of children and adolescents (Armstrong & Welsman, 2020c;Barker, Williams, Jones, & Armstrong, 2009). Peak V ̇O2 is strongly associated with athletic performance, particularly in endurance and team sports Armstrong & Welsman, 2020c;Sperlich et al, 2011;Sperlich et al, 2010), as well as with both current and long-term health.…”

“…Exercise is paramount for the current health and well-being, irrespective of age, though arguably more important during childhood and adolescence given that exercise habits in children are strongly associated with exercise levels in adulthood (Armstrong, 2007;Armstrong & Welsman, 2020c;Baquet, Van Praagh, & Berthoin, 2003;Matos & Winsley, 2007). Exercise is associated with numerous health-related benefits, including, but not limited to, improved physical (Armstrong & Welsman, 2020c;McNarry et al, 2014a;McNarry, Mackintosh, & Stoedefalke, 2014b) and mental health (Eddolls, McNarry, Stratton, Winn, & Mackintosh, 2017;Sabato, Walch, & Caine, 2016), enhanced social well-being (Mountjoy, 2008;Pene & Touitou, 2009), and a reduced risk of cardiovascular disease (CVD; Coombes, Law, Lancashire, & Fassett, 2015;Kaminsky et al, 2019) and all-cause mortality (Garatachea et al, 2014;Lemez & Baker, 2015). Creating a more active nation has been at the forefront of governmental policies for decades (UK Government, 2015), with the latest available data indicating that almost half of children and adolescents under 17 years of age in England and Wales participate in extra-curricular sport at least three times a week (Sport England, 2019;Sport Wales, 2018).…”

“…The effect of different training methodologies on various components of fitness has received substantial attention (Armstrong & Welsman, 2020c;Baquet et al, 2003;Cao, Quan, & Zhuang, 2019;Costigan, Eather, Plotnikoff, Taaffe, & Lubans, 2015; McNarry & Jones, 2014) but, despite decades of research, there remains little consensus as to whether endurance training or high-intensity interval training (HIIT)…”