Influence of maturation on anthropometry and body composition in Japanese junior high school students

Abstract

BackgroundThe purpose of this study was to examine maturity-related differences in anthropometry and body composition in Japanese youth within a single year.MethodsTwo hundred and ten Japanese youth aged from 13 to 13.99 years participated in this study. Their maturity status was assessed using a self-assessment of stage of pubic hair development. Bioelectrical impedance analysis was used to estimate percent body fat and lean body mass (LBM). Muscle thickness of the anterior thigh, posterior lower leg and rectus abdominis muscles were measured by ultrasound.ResultsFor boys, height, body weight, and LBM in less mature groups were lower than that in more mature groups. The maturity-related differences were still significant after adjusting for chronological age. On the other hand, muscle thickness values in the lower extremity and abdomen differed among the groups at different stages of pubic hair development, whereas there was no maturity-related difference in the relative values corrected by LBM, except for those thickness values measured at the abdomen. For girls, only the muscle thickness at the anterior thigh and muscle thickness relative to LBM1/3 at the posterior lower leg was significantly affected by maturity status, but significant maturity-related difference was not found after adjusting for chronological age.ConclusionsAt least for Japanese boys and girls aged 13 years, maturity status affected body size in boys, but not in girls, and the influence of maturation on the muscularity of the lower extremity and trunk muscles is less in both sexes.

Anthropometric, Physical, Cardiorespiratory Fitness and Lipids and Lipoproteins Profile of Young Indian Children of 10-16 Years Age Group

“…Moreover, this might be because of level of maturation factors and / or motivation of the Postpubertal children when compared with Prepubertal and Pubertal children. Similar findings were also noted by other research groups who reported significant reduction of reaction time; and elevation in flexibility, abdominal strength, elastic leg strength and grip strength, speed and power with the advancement of age, level of maturation and exposure to high intensity of exercise for long time among the children [31,42,43,44,47]. Monitoring of the motor skills and activities such as reaction time, hip and trunk flexibility, abdominal strength, elastic leg strength, grip strengths, maximum speed and peak power output at regular intervals is essential for selection of athletes for competitions and during the training seasons.…”

“…The changes might be because of level of maturation factors and / or motivation, and exposure to long term and higher intensity of training among the Postpubertal children when compared with Prepubertal and Pubertal children. Similar findings were also noted by other research groups who reported significant change in these parameters with the advancement of age, level of maturation and exposure to high intensity of exercise for long time among the children [42,43,44]. Monitoring of anthropometry and body composition at regular intervals is essential for selection of athletes for competitions.…”

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“…In all inter-hurdle distances, the boys who had shorter 50-m hurdle running times had greater body height (Figure 2-A) and shorter 50-m sprinting times (Figure 2-B). The 13 year-old boys who matured early were taller than the other boys (Fukunaga et al, 2013). This suggests that the boys who were faster in hurdle running were not only taller, but early matured body whose physical fitness is high (Fukunaga et al, 2013;Kato et al, 1999;Otsuka et al, 2010;Tanner, 1962).…”

“…The 13 year-old boys who matured early were taller than the other boys (Fukunaga et al, 2013). This suggests that the boys who were faster in hurdle running were not only taller, but early matured body whose physical fitness is high (Fukunaga et al, 2013;Kato et al, 1999;Otsuka et al, 2010;Tanner, 1962). Therefore, in junior high school PE, the hurdle running unit may involve a level of uncertainty, as to winners are possibly determined even before the race.…”

“…Peak height velocity in Japanese boys occurs between 12-13 years old (Ministry of Education, Culture, Sports, Science and Technology in Japan, 2014), and this timing shifts before and after based on the individuals (Tanner, 1962). In Japan, 13-year-old boys who have matured early are taller than other boys (Fukunaga et al, 2013). This suggests that in PE classes for junior high school 1st and 2nd grades, there may be a wide range of body heights between various boys.…”