Retrospective longitudinal growth study of boys and girls active in sport

Growth status and age at peak height velocity among youth participants in several sports: the Cracow longitudinal study

BACKGROUND

Studies addressing age at peak height velocity (PHV) in longitudinal samples of participants in sports are relatively limited.

PURPOSE

To compare the growth status and estimated ages at PHV of longitudinal samples girls and boys active in sport with peers not active in sport, and to compare estimated ages at PHV among longitudinal samples of Polish youth active in sport.

METHODS

Records from the Cracow Longitudinal Study, which measured youth annually from 8 to 18 years, were screened to identify individuals regularly active in sport. Participants in athletics (22 girls, 10 boys), soccer (12 boys), and other team (6 girls, 7 boys) and individual (6 girls, 9 boys) sports were identified; 107 girls and 172 boys were not active in sport. Heights and weights of participants in sports and non-involved peers were compared. Longitudinal height records of individuals were fit with the SITAR model to estimate age at PHV. Ages at PHV of boys and girls active in sport and peers not active in sports were compared with sex-specific ANOVAs.

RESULTS

Ages at PHV of boys participating in athletics and soccer were similar to age at PHV of boys not active in sport, while ages at PHV of boys in other team sports (basketball, volleyball, handball) and individual sports (skiing, gymnastics, acrobatics) were, respectively, slightly earlier and later. Among girls, age at PHV of participants in team sports (basketball, netball) was earlier, while ages at PHV among participants in athletics and other individual sports (equestrian, acrobatics, shooting) were slightly later compared to non-athlete peers.

CONCLUSION

Ages at PHV varied among participants in different sports and were consistent with estimates in other longitudinal samples of Polish youth athletes.

Physical Fitness and Upper Limb Asymmetry in Young Padel Players: Differences between Genders and Categories

This study aimed to assess the physical fitness and upper body asymmetries of young padel players aged between 13 and 16 years and to determine the possible differences between genders and categories. A total of 60 padel players were divided into four groups: under-14 male (n = 15; age: 13.75 ± 0.45 years; height: 1.64 ± 0.07 m; weight: 54.7 ± 8.3 kg), under-14 female (n = 15; age: 13.75 ± 0.44 years; height: 1.60 ± 0.05 m; weight: 51.5 ± 6.0 kg), under-16 male (n = 15; age: 15.44 ± 0.51 years; height:1.71 ± 0.04 m; weight: 63.88 ± 6.2 kg) and under-16 female (n = 15; age:15.46 ± 0.52 years; height:1.63 ± 0.05 m; weight: 55.08 ± 3.6 kg). Handgrip strength, ischiosural flexibility, gestural speed of the dominant arm, vertical jump, cardiorespiratory capacity, lateral movement, lateral acceleration and reaction time were measured. Male players showed better results in manual grip strength, vertical jump power, cardiorespiratory capacity and lateral movement (p < 0.05). Moreover, males presented a higher percentage of asymmetry in upper limb strength. Female players showed better reaction time and greater flexibility (p < 0.05). Regarding the differences between categories, the under-16 players showed greater flexibility, gestural speed, vertical jump power, cardiorespiratory capacity and lateral movement compared to the under-14 players. These results can be used as reference values for coaches/physical trainers of younger categories to improve health control and physical performance planning.

Peer Group Similarity in Perceptions of Pubertal Timing

Self-report measures of perceived pubertal timing correspond only weakly with clinical measures of "objective" physical development. Peer and school contexts shape adolescents' self-perceptions of pubertal timing. The current study examined associations between perceived pubertal timing and the pubertal timing reported by nominated friends and schoolmates. Participants included 2817 adolescents (Mage = 16.6; 49 % female; 16 % Black; 20 % Hispanic) from the National Longitudinal Study of Adolescent Health. Three measures of pubertal timing were included: age-standardized ratings of body changes, comparisons of development relative to peers (relative timing), and, in females, age at menarche. It was hypothesized that relative timing, which explicitly asks adolescents to compare themselves to their peers, would be related to the age-standardized pubertal timing of nominated friends and schoolmates. Surprisingly, there were no associations between relative timing and age-standardized pubertal timing reported by peers, suggesting that pubertal self-perceptions do not fluctuate in response to the average level of development in a friend group. Instead, males were similar to nominated friends and schoolmates in age-standardized ratings of body changes, and females were similar to nominated friends in relative timing, controlling for race, ethnicity, and age. Different self-report measures of pubertal timing index different underlying constructs, and the social processes that influence adolescents' perceptions of pubertal maturation may differ between genders.

Biological maturation of youth athletes: assessment and implications

The search for talent is pervasive in youth sports. Selection/exclusion in many sports follows a maturity-related gradient largely during the interval of puberty and growth spurt. As such, there is emphasis on methods for assessing maturation. Commonly used methods for assessing status (skeletal age, secondary sex characteristics) and estimating timing (ages at peak height velocity (PHV) and menarche) in youth athletes and two relatively recent anthropometric (non-invasive) methods (status-percentage of predicted near adult height attained at observation, timing-predicted maturity offset/age at PHV) are described and evaluated. The latter methods need further validation with athletes. Currently available data on the maturity status and timing of youth athletes are subsequently summarised. Selection for sport and potential maturity-related correlates are then discussed in the context of talent development and associated models. Talent development from novice to elite is superimposed on a constantly changing base-the processes of physical growth, biological maturation and behavioural development, which occur simultaneously and interact with each other. The processes which are highly individualised also interact with the demands of a sport per se and with involved adults (coaches, trainers, administrators, parents/guardians).

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

BACKGROUND

The purpose of this study was to examine maturity-related differences in anthropometry and body composition in Japanese youth within a single year.

METHODS

Two 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.

RESULTS

For 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.

CONCLUSIONS

At 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.

Gender Disparity in Structured Physical Activity and Overall Activity Level in Adolescence: Evaluation of Youth Risk Behavior Surveillance Data

Background. Adolescent girls are less likely to meet physical activity recommendations than boys. This study examined the relative contribution of structured physical activity opportunities including physical education (PE) class and sports teams to overall activity levels for girls and boys. Methods. Data from 591 9th–12th grade students who completed the 2009 Philadelphia Youth Risk Behavior Survey were examined. Logistic regression was used to estimate the relationship between PE and sports teams and physical activity levels. Models were stratified by gender to estimate gender differences. Results. Girls were less likely to be active than boys: 27.9% of girls were sedentary as compared to 10.6% of boys. PE class was not related to activity levels among boys, while highly active girls were seven times more likely to participate in daily PE than were sedentary girls. Playing on one or more sports teams was associated with low-moderate and high activity in girls; among boys, sports team participation was only associated with high activity. Conclusions. The structured physical activity opportunities of PE and sports teams may contribute more to overall activity levels in girls than boys. A more rigorous assessment of this hypothesis is warranted to inform efforts to promote activity levels in girls.

A fatigue questionnaire (QFES) for child athletes: a four-year follow-up study in young skiers

BACKGROUND

The use of a fatigue monitoring questionnaire is an increasingly widespread practice in sports medicine.

OBJECTIVE

To evaluate variations in the QFES fatigue questionnaire score according to periods of rest, training or competition.

METHODS

Sixty-six skiers (either alpine or cross-country skiers, aged between 11 and 14 years and training for between 12 and 18 hours per week) filled out a total of 400 fatigue questionnaires over a four-year follow-up period.

RESULTS

Our analysis of the QFES fatigue scores showed that only a small proportion of the skiers (5.25%, on average) exceeded the fatigue alert threshold at some point during the longitudinal follow-up; periods of competition correspond to rising fatigue scores, in comparison with the beginning of season and girls always have higher scores than boys (25.32+/-0.90 versus 20.46+/-0.91, respectively; p<0.0002). In contrast, there was no correlation between fatigue levels and the type of skiing discipline practiced.

CONCLUSION

Our main results show that the QFES fatigue questionnaire is a sensitive tool for tracking down particular periods of fatigue (competition, intense training). Even though the mechanism of fatigue is still not fully understood (highlighting the complexity of this syndrome), the systematic use of a fatigue questionnaire when monitoring children performing competitive sport and high volumes of training confirms the possible preventive role of this type of tool.

Optimum onset period for training based on maximum peak velocity of height by wavelet interpolation method in Japanese high school athletes

The Wavelet Interpolation Method (WIM) was applied to the longitudinal records of individuals' heights and weights from 6 to 17 years of age (1983 to 1994) in an athlete group (male: 45, female: 50) and a control group (male: 85, female: 85). The criterion of maturity was derived from age at Maximum Peak Velocity (MPV) of height in the control group. Ages at MPV of height and weight were compared between the athletes and control subjects. The WIM was also applied to mean heights from 6.5 to 17.5 years of all the subjects classified by maturation rate in order to derive a model of growth velocity types. Among the athletes, the males were early-maturing and the females tended to be late-maturing. The difference between the ages at MPV of height and weight in males and females was less in the athletes group than in the control group. For the growth velocity model, in the athlete group, three types could be confirmed among the males, and five among the females. By making use of the type models, it was possible to clarify the spans of adolescence as classified by maturation rates, and it was concluded that the period following the age at MPV seems appropriate for the introduction of regular athletic training for each level of maturity.

Factors affecting levels of physical activity in adults

A large proportion of adults in Western cultures are physically inactive, despite several decades of warnings about the potentially negative health consequences of a sedentary lifestyle. Efforts to promote physical activity have focused on identifying its determinants and designing interventions that might effectively promote regular physical activity. The multitude of factors that induce adults to initiate and maintain programmes of physical activity have been divided into those that are invariable (age, gender, race, ethnicity) and those that are presumed to be modifiable (behavioural and personality characteristics, environmental circumstances and community settings). The lack of consistency in the design, analysis and reporting of interventions in the lives of inactive or sedentary individuals has produced equivocal results. However, several social and environmental factors have systematically emerged as determinants of physical activity in adults. In ethnic minorities, the removal of barriers such as unaffordable facilities and unavailable childcare, high crime rates, fear for personal safety and culturally inappropriate activities are of primary importance. Social support from family, peers, communities and healthcare providers has resulted in modest improvements across cultures, ages and genders in selected settings, but the definition of specific interventions and their outcomes deserve additional attention. Longitudinal studies indicate that components of physical fitness are relatively transitory, with low to modest correlations between physical activity and measures of physical fitness in childhood and adolescence and in adulthood. Attempts to explain the activity behaviour of adults by applying various theories in programmes of intervention have also produced mixed results. Successful interventions tailor programmes to individual needs, account for personal levels of fitness, allow for personal control of the activity and its outcomes, and provide for social support by family, peers and communities. The initiation and maintenance of regular physical activity in adults depends on a multitude of biological and sociocultural variables that demand attention across the lifespan.

Longitudinal growth study of male Japanese junior high school athletes

The aim of this study was to establish the pattern of adolescent growth in height of male Japanese athletes, and to compare their growth with appropriate controls. The sample consisted of 126 baseball, 39 basketball, 83 soccer, and 53 volleyball players, and 36 nonathletes. The data were collected retrospectively in six public schools in Fukui Prefecture of Western Japan between 1970 and 1987. All subjects were measured at yearly intervals between the age of 6 and 18 years. The total number of measurement occasions for the 337 subjects amounted to 4,134. Athletes trained between 13 and 18 h/week. Individual growth patterns were determined by fitting Preece Baines model I to each individual's serial data. Various biological parameters were derived from the fitted curves. The results indicated that the average growth pattern of these adolescent athletes did not differ substantially from the control group. Volleyball players were significantly taller at 18 years (+3 cm) than the nonathletes (Student's t-test, P < 0.05). Soccer players showed a slight tendency towards late maturation with age at take-off and at peak velocity about half a year later than in nonathletes (Student's t-test, P < 0.05). The 2.3 cm gain in body height due to the later onset of the pubertal growth spurt in soccer players was counterbalanced by a 0.7 cm smaller prepubertal height and a 0.9 cm smaller adolescent gain, so that they ended up slightly, but not significantly, taller than the controls (+0.7 cm). The small differences in growth pattern observed between the nonathletes and the various sports suggest that, in contrast with top-level athletes, body size and maturation rate were not important selective factors in the various groups of athletes of the present study.

Anthropometric characteristics of elite female junior rowers

During the 1997 Federation Internationale des Sociétés d'Aviron (FISA) World Junior Rowing Championships, the anthropometric characteristics of 245 female junior rowers aged 17.5 +/- 0.8 years (mean +/- s) were assessed. Twenty-seven body dimensions (body mass, 6 heights or lengths, 4 breadths, 10 girths and 6 skinfolds) were measured in total. The elite female junior rowers were taller (174.5 +/- 6.2 cm) and heavier (69.5 +/- 6.2 kg), with greater length, breadth and girth dimensions, but lower skinfold thicknesses than a representative sample of Flemish (Belgian) girls of the same chronological age. An anthropometric profile chart was constructed that was rowing-specific and norms were established. Compared with scullers, sweep rowers were heavier (+4.2 kg) and taller (+2.8 cm), with greater length, breadth (except for femur width) and girth dimensions (except for calf girth). Sweep rowers also had greater skinfold thicknesses (except for the thigh and calf skinfolds). Finalists were heavier (+3.6 kg) and taller (+3.9 cm), with greater length, breadth (except for femur width) and girth dimensions (except for calf girth) than non-finalists. No significant differences were found for skinfold thicknesses between finalists and non-finalists.

Is prepubertal growth adversely affected by sport?

PURPOSE

To study the effect of genetic factors, birth weight, early childhood growth, sport, hours of training, and pubertal status on the stature and body mass index (BMI) of children aged 9-13 participating in sports at a competitive level.

METHODS

A total of 184 children (96 girls, 88 boys), competing in swimming, tennis, team handball, and gymnastics, were investigated, assessing their height, weight, pubertal development, and BMI. Of these, 137 (76 girls, 61 boys) returned a questionnaire, which enabled us to determine height and BMI at age 2-4, birth weight, and parental heights.

RESULTS

Significant differences in standard deviation scores (SDS) for actual height and for height at age 2-4 were found in both sexes between the four sports. In girls, BMI SDS was significantly different between the four sports, whereas no difference was found in boys. Each sport investigated separately showed no change in height SDS and BMI SDS between ages 2-4 and 9-13. A regression analysis showed that target height, height at age 2-4, and pubertal status had a significant impact on actual height. Interestingly, the type of sport and hours of training per week had no effect on height SDS. In boys, BMI at age 2-4 and pubertal status had a significant effect on actual BMI, whereas in girls, only BMI at age 2-4 was significant.

CONCLUSIONS

The results suggest that prepubertal growth is not adversely affected by sport at a competitive level and that constitutional factors are of importance for choice of sport in children.

Peak bone mineral accrual and age at menarche in adolescent girls: a 6-year longitudinal study

BACKGROUND AND OBJECTIVES

The greatest increase in bone mineral content occurs during adolescence. The amount of bone accrued may significantly affect bone mineral status in later life. We carried out a longitudinal investigation of the magnitude and timing of peak bone mineral content velocity (PBMCV) in relation to peak height velocity (PHV) and the age at menarche in a group of adolescent girls over a 6-year period.

METHODS

The 53 girls in this study are a subset of the 115 girls (initially 8 to 16 years) in a 6-year longitudinal study of bone mineral accretion. The ages at PBMCV and PHV were determined by using a cubic spline curve fitting procedure. Determinations were based on height (n = 12) and bone (n = 6) measurements over 6 years.

RESULTS

The timing of PBMCV and menarche were coincident, preceded approximately 1 year earlier by PHV. Correlation showed a negative relationship between age at menarche and both peak bone mineral accrual (r = -0.42, P < .002) and PHV (r = -0.45, P < .001).

CONCLUSIONS

This longitudinal study demonstrated the close association between age at PBMCV and age at menarche and confirmed the relationship between greater PBMCV and PHV in earlier, as compared with later, maturing girls.

The adolescent spurt and sexual maturation in girls active and not active in sport

Girls actively training in sport (n=23) and girls not active in sport (n=26) were compared in terms of ages at peak height velocity (PHV) and menarche, the interval between ages at PHV and menarche, and ages at attaining stages of pubic hair and breast and the estimated duration of the stages. Subjects were longitudinally followed from about 11-18 years of age. Stature and weight were measured and stages of pubic hair and breast development were rated at approximately quarterly intervals between the initial observation and 14 years of age, at semiannual intervals until 16 years, and at irregular intervals subsequently. Age at menarche was obtained prospectively. The active girls trained 12 hours per week in rowing, track and swimming for an average of 3.9+/-1.2 years during puberty and the growth spurt. Longitudinal stature records for individual girls were fitted with kernel regression to estimate age at PHV (years). The interval between age at PHV and age at menarche was calculated. Ages at appearance of pubic hair and breast stages 3, 4 and 5 were calculated by back-interpolation, while intervals between stages 3 and 4 were calculated after log 10 transformation. Peak height velocity and menarche occur, on average, slightly later in girls active in sport, but the differences are not significant. The interval between PHV and menarche, PHV (cm/year), ages at attaining pubic hair and breast stages 3, 4 and 5, and estimated intervals between adjacent stages also do not significantly differ between girls actively training in sport and those not active in sport. Thus, regular training in sport during puberty and the adolescent spurt does not apparently influence the timing and progression of somatic and sexual maturation in girls.