In the early 1900s it was thought that exercise directly stimulated growth; however, by the end of the century it was suggested that young athletes were selected based on inherited physical attributes that enhanced performance success. In this paper, the physical attributes and normal patterns of growth of young athletes, both competitive and recreational, are discussed. Specifically, the paper addresses the question, Are young athletes born with physical attributes suited to a sport or does sport training produce these physical attributes? Variability in the tempo and timing of normal growth and development is addressed, and its relevance and influence on youth talent identification is discussed. This is pertinent in today’s context of sport specialization at relatively young ages. Regular physical training is only one of many factors that could affect child growth; however, distinguishing influences of training programs on growth from those associated with normal growth and development is problematic.
Adam D.G. Baxter-Jones
Job Fransen, Adam Baxter-Jones and Stephen Woodcock
Adam D.G. Baxter-Jones and Peter J. Helms
This paper reviews the findings from a longitudinal study following the growth and development of young British athletes. Four sports were studied: gymnastics, soccer, swimming, and tennis. Four main areas of concern were identified and studied: sports injury, growth and development, psychological and psychosocial problems, and physiological functioning. No evidence was found to suggest that training affected growth or sexual development. The incidence and severity of injuries was low. Athletes were shown to have a healthy lifestyle. The negative effects of intensive training at a young age were outweighed by the many social, psychological and health benefits that a serious commitment to sport brought these young people.
Geraldine Naughton, David Greene, Daniel Courteix and Adam Baxter-Jones
Adam D.G. Baxter-Jones, Nicola Maffulli and Robert L. Mirwald
Adam Ayash and Margaret T. Jones
Edited by Trent Nessler
Emily Arentson-Lantz, Elfego Galvan, Adam Wacher, Christopher S. Fry and Douglas Paddon-Jones
Physical activity in an inpatient setting is often limited to brief periods of walking. For healthy adults, public health agencies recommend a minimum of 150 min/week of moderate-intensity exercise. The authors sought to determine if meeting this activity threshold, in the absence of incidental activities of daily living, could protect skeletal muscle health during bed rest. Healthy older adults (68 ± 2 years) were randomized to 7-day bed rest with (STEP, n = 7) or without (CON, n = 10) a 2,000 steps/day intervention. Performing 2018 ± 4 steps/day did not prevent the loss of lean leg mass and had no beneficial effect on aerobic capacity, strength, or muscle fiber volume. However, the insulin response to an oral glucose challenge was preserved. Performing a block of 2,000 steps/day, in the absence of incidental activities of daily living, was insufficient to fully counter the catabolic effects of bed rest in healthy older adults.
Adam R. Nicholls, John L. Perry, Leigh Jones, Dave Morley and Fraser Carson
It is accepted among scholars that coping changes as people mature during adolescence, but little is known about the relationship between maturity and coping. The purpose of this paper was to assess a model, which included dispositional coping, coping effectiveness, and cognitive social maturity. We predicted that cognitive social maturity would have a direct effect on coping effectiveness, and also an indirect impact via dispositional coping. Two hundred forty-five adolescent athletes completed measures of dispositional coping, coping effectiveness, and cognitive social maturity, which has three dimensions: conscientiousness, peer influence on behavior, and rule following. Using structural equation modeling, we found support for our model, suggesting that coping is related to cognitive social maturity. This information can be used to influence the content of coping interventions for adolescents of different maturational levels.
Adam D. G. Baxter-Jones, Joey C. Eisenmann and Lauren B. Sherar
The process of maturation is continuous throughout childhood and adolescence. In a biological context, the effects of a child’s maturation might mask or be greater than the effects associated with exposure to exercise. Pediatric exercise scientists must therefore include an assessment of biological age in study designs so that the confounding effects of maturation can be controlled for. In order to understand how maturation can be assessed, it is important to appreciate that 1 year of chronological time is not equivalent to 1 year of biological time. Sex- and age-associated variations in the timing and tempo of biological maturation have long been recognized. This paper reviews some of the possible biological maturity indicators that the pediatric exercise scientist can use. As a result, we recommend that any of the methods discussed could be used for gender-specific comparisons. Gender-comparison studies should either use skeletal age or some form of somatic index.
Job Fransen, Stephen Bush, Stephen Woodcock, Andrew Novak, Dieter Deprez, Adam D.G. Baxter-Jones, Roel Vaeyens and Matthieu Lenoir
Purpose: This study aimed to improve the prediction accuracy of age at peak height velocity (APHV) from anthropometric assessment using nonlinear models and a maturity ratio rather than a maturity offset. Methods: The dataset used to develop the original prediction equations was used to test a new prediction model, utilizing the maturity ratio and a polynomial prediction equation. This model was then applied to a sample of male youth academy soccer players (n = 1330) to validate the new model in youth athletes. Results: A new equation was developed to estimate APHV more accurately than the original model (new model: Akaike information criterion: −6062.1, R 2 = 90.82%; original model: Akaike information criterion = 3048.7, R 2 = 88.88%) within a general population of boys, particularly with relatively high/low APHVs. This study has also highlighted the successful application of the new model to estimate APHV using anthropometric variables in youth athletes, thereby supporting the use of this model in sports talent identification and development. Conclusion: This study argues that this newly developed equation should become standard practice for the estimation of maturity from anthropometric variables in boys from both a general and an athletic population.