This longitudinal study evaluates the relationship of food intake and physical activity with biological maturation of 200 boys and girls during adolescence and young adulthood. The subjects were followed during 9 years from ages 12 to 22 years, with repeated measurements at ages 13, 14, 15, 16, and 21. Biological maturation was estimated four times between ages 12 and 17 as skeletal age by radiographs of the left hand and wrist. Daily nutritional intake (macro- and micronutrients) was assessed with a cross-checked dietary history method. Daily physical activity was assessed through structured interview, whereby average weekly time spent in activity was used to assign a weighted activity score. The 107 girls and 93 boys were divided into three maturity groups: early maturers, late maturers, and average maturers. It was concluded that in both sexes, late maturation seemed to coincide with a higher energetic food intake and a slightly higher activity pattern than early maturation during adolescence.
Han C.G. Kemper, G. Bertheke Post and Jos W.R. Twisk
Gillian K. Myburgh, Sean P. Cumming, Manuel Coelho E. Silva, Karl Cooke and Robert M. Malina
To evaluate relationships among skeletal maturity, body size, and functional capacities of elite junior tennis players.
Participants were 88 elite British Junior tennis players (44 male; 44 female), 8–16 years of age (12.4 } 1.9 years). Skeletal age estimated maturty. Anthropometry, grip strength, countermovement jump, squat jump, forehand agility, backhand agility, Yo-Yo, 5-m, 10-m and 20-m sprints were measured. Comparative analysis for each sex was performed, relating advanced maturers (Male: 15; Female: 29) to a combination of on-time and late maturers (Male: 29; Female: 31). ANCOVAs were used to determine absolute differences between male and female players and between the 2 maturity subgroups, with chronological age as the covariate.
Advanced maturity afforded male players advantages in absolute measures of grip strength, speed, upper and lower body power but not in acceleration, agility or aerobic endurance. Male players were significantly taller than females in the U13-U16 age group. Advanced maturity in female players afforded advantages in absolute measures of grip strength, agility and overhead power, but not in backhand agility, aerobic endurance or squat jump power.
It is important that talent identification protocols consider the maturity of youth athletes to more satisfactorily address athletic potential rather than transient physical capabilities.
Bareket Falk, Sarah Braid, Michael Moore, Deborah O’Leary, Phil Sullivan and Panagiota Klentrou
The objective of this study was to assess bone strength using quantitative ultrasound (QUS, Sunlight Omnisense) in pre- and early-pubertal normal weight (NW, % body fat ≤20, n = 28), and overweight (OW, % body fat ≥25, n = 15) boys. Groups were similar in chronological and skeletal age, sexual maturity, sports participation, and calcium intake. Leisure-time physical activity was lower in OW boys. Radial speed of sound (SOS) was similar in the two groups. Tibial SOS, however, was significantly lower in OW compared with NW (3,554 ± 109 vs. 3,646 ± 71 m·s−1, respectively). Among pre- and early-pubertal boys, higher adiposity appears to be associated with lower bone SOS in the lower extremities.
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.
Eleni Michopoulou, Alexandra Avloniti, Antonios Kambas, Diamanda Leontsini, Maria Michalopoulou, Symeon Tournis and Ioannis G. Fatouros
This study determined dietary intake and energy balance of elite premenarcheal rhythmic gymnasts during their preseason training. Forty rhythmic gymnasts and 40 sedentary age-matched females (10–12 yrs) participated in the study. Anthropometric profile and skeletal ages were determined. Dietary intake and physical activity were assessed to estimate daily energy intake, daily energy expenditure, and resting metabolic rate. Groups demonstrated comparable height, bone age, pubertal development, resting metabolic rate. Gymnasts had lower body mass, BMI, body fat than age-matched controls. Although groups demonstrated comparable daily energy intake, gymnasts exhibited a higher daily energy expenditure resulting in a daily energy deficit. Gymnasts also had higher carbohydrate intake but lower fat and calcium intake. Both groups were below the recommended dietary allowances for fiber, water, calcium, phosphorus and vitamin intake. Gymnasts may need to raise their daily energy intake to avoid the energy deficit during periods of intense training.
Hazzaa M. Al-Hazzaa, Saeed A. Al-Refaee, Muhammed A. Sulaiman, Ma’ed Y. Dafterdar, Abdullah S. Al-Herbish and Andrew C. Chukwuemeka
The purpose of this study was to examine the maximal cardiorespiratory responses of trained adolescent male swimmers (SWM, N = 18), soccer players (SOC, N = 18), and moderately active reference subjects (CON, N = 16) to treadmill running (TRD) and arm ergometry (ARM). Mean values (±SD)for skeletal age were similar among the three groups (12.5± 1.9, 12.7 ± 1.1, and 12.5 ± 1.6 years, for the SWM, SOC, and CON, respectively). Allometric scaling procedures, relating VO2max and body mass, were used and mass exponents of .80 and .74 were identified for TRD and ARM data, respectively. During TRD testing SOC attained significantly higher VO2max values when expressed in ml · kg−1 · min−1, or ml · kg−0.80 · min−1 than the other two groups. However, during ARM testing, the SWM achieved significantly higher VO2peak values (ml · kg−0.74 · min−1 and scaled to arm-CSA) than SOC. The ratio of ARM-VAT to TRD-VAT was significantly higher in SWM (50.1± 9%) compared to SOC (41.2±5%), or CON (41.9 ± 6%).
António J. Figueiredo, Manuel J. Coelho e Silva, Sean P. Cumming and Robert M. Malina
The purpose of the study was to compare the anthropometric, functional and sport-specific skill characteristics and goal orientations of male youth soccer players at the extremes of height and skeletal maturity in two competitive age groups, 11–12 and 13–14 years. The shortest and tallest players, and least and most skeletally mature players (n = 8 per group) within each age group were compared on chronological age; skeletal age (Fels method); pubertal status (pubic hair); size, proportions and adiposity; four functional capacities; four soccer-specific skills; and task and ego orientation. The tallest players were older chronologically, advanced in maturity (skeletal, pubertal) and heavier, and had relatively longer legs than the shortest players in each age group. At 11–12 years, the most mature players were chronologically younger but advanced in pubertal status, taller and heavier with more adiposity. At 13–14 years, the most mature players were taller, heavier and advanced in pubertal status but did not differ in chronological age compared with the least mature players. Players at the extremes of height and skeletal maturity differed in speed and power (tallest > shortest; most mature > lest mature), but did not differ consistently in aerobic endurance and in soccer-specific skills. Results suggested that size and strength discrepancies among youth players were not a major advantage or disadvantage to performance. By inference, coaches and sport administrators may need to provide opportunities for or perhaps protect smaller, skilled players during the adolescent years.
Job Fransen, Stephen Bush, Stephen Woodcock, Andrew Novak, Dieter Deprez, Adam D.G. Baxter-Jones, Roel Vaeyens and Matthieu Lenoir
fitness variables are strongly correlated with successful performance outcomes. There are numerous ways to assess an individual’s biological maturation. The traditional clinical methods consist of assessing skeletal age through X-ray of the wrist or the assessment of secondary sex characteristics ( 15
Adam D.G. Baxter-Jones
assessment of skeletal age and are thus not practical outside of a clinical setting. Recently, predictive equations have been developed that do not require a measure of skeletal age ( Beunen et al., 1997 ; Khamis & Roche, 1994 ; Sherar et al., 2005 ) and have potential for use in pediatric studies
Ida S. Svendsen, Espen Tønnesen, Leif Inge Tjelta and Stein Ørn
-15) according to biological maturity . Int J Sports Med . 2015 ; 36 : 16 – 21 . PubMed ID: 25144439 25144439 20. Hirose N . Relationships among birth-month distribution, skeletal age and anthropometric characteristics in adolescent elite soccer players. J Sports Sci . 2009 ; 27 : 1159 – 1166