Menarche in intensively trained gymnasts, swimmers and tennis players

The Effect of Growth and Body Surface Area on Cardiopulmonary Exercise Testing: A Cohort Study in Preadolescent Female Swimmers

BACKGROUND

The performance of young swimmers is the result of a multifactorial process that is influenced by anthropometric characteristics and biological maturation. The purpose of our study was to investigate the effect of stages of biological maturation and body surface area on cardiopulmonary fitness indicators in preadolescent female swimmers, for whom menstruation has not started.

METHODS

Thirty female preadolescent swimmers (age 13.4 ± 1.0 years) participated in this study. We recorded anthropometric and morphological characteristics, stages of biological maturation, and pulmonary function parameters, and the swimmers underwent cardiopulmonary exercise testing.

RESULTS

The cut-off was set for body surface area (BSA) at 1.6 m2 and for biological maturation stages at score 3. The BSA results showed differences in variabilities in maximal effort oxygen pulse (p < 0.001), oxygen uptake (p < 0.001), ventilation (p = 0.041), tidal volume (p < 0.001), and oxygen breath (p < 0.001). Tanner stage score results showed differences in variabilities in maximal effort breath frequency (p < 0.001), tidal volume (p = 0.013), and oxygen breath (p = 0.045). Biological maturation stages and BSA were correlated during maximal effort with oxygen breath (p < 0.001; p < 0.001), oxygen uptake (p = 0.002; p < 0.001), and oxygen pulse (p < 0.001; p < 0.001).

CONCLUSIONS

In conclusion, the findings of our study showed that the girls who had a smaller body surface area and biological maturation stage presented lower values in maximal oxygen uptake and greater respiratory work.

Exploring adolescence as a key life history stage in bioarchaeology

Adolescence is a unique period in the life history of an individual. It is characterized by a myriad of changes that bioarchaeologists are only just coming to appreciate, related to sexual maturation, linear growth, immunological transformation, and emotional and cognitive development. New methods allow us to measure this age of transition through the stages of the adolescent growth, as a proxy for the physical development associated with sexual maturation (puberty). This review outlines ways bioarchaeologists may draw on research developments from the fields of human biology, evolutionary theory and neurobiology to advance a more holistic approach to the study of adolescence in the past. It considers current theoretical and analytical approaches to highlight the research potential of this critical stage of life history. This synthesis integrates the most recent research in the medical sciences concerned with body and brain development, and outlines the biological processes involved with sexual and physical maturation of the adolescent. The goal of this review is to help inform potentially rewarding areas of research that bioarchaeologists can contribute to and draw from, as well as the challenges and limitations, theoretical and methodological questions, and ways in which we can develop the study of adolescence in the discipline going forward.

A Systematic Literature Review of Factors Affecting the Timing of Menarche: The Potential for Climate Change to Impact Women's Health

Menarche is the first occurrence of a woman’s menstruation, an event that symbolizes reproductive capacity and the transition from childhood into womanhood. The global average age for menarche is 12 years and this has been declining in recent years. Many factors that affect the timing menarche in girls could be affected by climate change. A systematic literature review was performed regarding the timing of menarche and four publication databases were interrogated: EMBASE, SCOPUS, PubMed, and Cochrane Reviews. Themes were identified from 112 articles and related to environmental causes of perturbations in menarche (either early or late), disease causes and consequences of perturbations, and social causes and consequences. Research from climatology was incorporated to describe how climate change events, including increased hurricanes, avalanches/mudslides/landslides, and extreme weather events could alter the age of menarche by disrupting food availability or via increased toxin/pollutant release. Overall, our review revealed that these perturbations in the timing of menarche are likely to increase the disease burden for women in four key areas: mental health, fertility-related conditions, cardiovascular disease, and bone health. In summary, the climate does have the potential to impact women’s health through perturbation in the timing of menarche and this, in turn, will affect women’s risk of disease in future.

Variation in menarcheal age of school-aged female athletes engaged in different types of sport

It is widely known from the literature that the rate of physical development and sexual maturation is not only determined by genetics but is also modified by physical workload factors. Given the above, this paper aimed at comparing menarcheal age of school-aged athletes engaged in different types of sport (and their respective workloads) after controlling for physical traits such as body height and mass and slenderness ratio. The survey was conducted in 2017 in 6 sports schools in Poland’s Lubuskie Voivodeship. Body height and mass were measured and the slenderness index (body height divided by the cubic root of body weight) was used to establish body build. The age of menarche was self-reported by the study participants. In total, 232 girls aged 9–18 were included in the research, of whom 125 reported their age of menarche. The age-adjusted arithmetic means and standard deviations were calculated for the study participants’ estimates. The raw data were then transformed into standardized z-score values. The significance of differences was assessed by Mann-Whitney U test as an alternative to the t-test when a given variable was not normally distributed. Pearson’s correlation coefficient was used to evaluate linear relations between the workload and age at menarche. It was found that dancers, acrobats and swimmers reported the youngest menarcheal ages. Girls practising most demanding sport disciplines (in terms of strength and endurance) reported the oldest age at menarche. Girls practising more than 3 times per week had menarche later than those practising 3 times a week or less, and the difference was statistically significant. In conclusion it might be stated that the type of sport discipline has a significant effect on age of menarche. Sport disciplines involving heavier physical exertion usually delay the onset of menstruation.

Triceps Surae Muscle-Tendon Unit Properties in Preadolescent Children: A Comparison of Artistic Gymnastic Athletes and Non-athletes

Knowledge regarding the effects of athletic training on the properties of muscle and tendon in preadolescent children is scarce. The current study compared Achilles tendon stiffness, plantar flexor muscle strength and vertical jumping performance of preadolescent athletes and non-athletes to provide insight into the potential effects of systematic athletic training. Twenty-one preadolescent artistic gymnastic athletes (9.2 ± 1.6 years, 15 girls) and 11 similar-aged non-athlete controls (9.0 ± 1.7 years, 6 girls) participated in the study. The training intensity and volume of the athletes was documented for the last 6 months before the measurements. Subsequently, vertical ground reaction forces were measured with a force plate to assess jumping performance during squat (SJ) and countermovement jumps (CMJ) in both groups. Muscle strength of the plantar flexor muscles and Achilles tendon stiffness were examined using ultrasound, electromyography, and dynamometry. The athletes trained 6 days per week with a total of 20 h of training per week. Athletes generated significantly greater plantar flexion moments normalized to body mass compared to non-athletes (1.75 ± 0.32 Nm/kg vs. 1.31 ± 0.33 Nm/kg; p = 0.001) and achieved a significantly greater jump height in both types of jumps (21.2 ± 3.62 cm vs. 14.9 ± 2.32 cm; p < 0.001 in SJ and 23.4 ± 4.1 cm vs. 16.4 ± 4.1 cm; p < 0.001 in CMJ). Achilles tendon stiffness did not show any statistically significant differences (p = 0.413) between athletes (116.3 ± 32.5 N/mm) and non-athletes (106.4 ± 32.8 N/mm). Athletes were more likely to reach strain magnitudes close to or higher than 8.5% strain compared to non-athletes (frequency: 24% vs. 9%) indicating an increased mechanical demand for the tendon. Although normalized muscle strength and jumping performance were greater in athletes, gymnastic-specific training in preadolescence did not cause a significant adaptation of Achilles tendon stiffness. The potential contribution of the high mechanical demand for the tendon to the increasing risk of tendon overuse call for the implementation of specific exercises in the athletic training of preadolescent athletes that increase tendon stiffness and support a balanced adaptation within the muscle-tendon unit.

Thrombophilic Genetic Anomalies and Their Association With Dialysis Initiation Age in a Cohort of Lebanese Hemodialysis Patients

OBJECTIVES

The relationship between chronic kidney disease and cardiovascular disease is complex and bidirectional. This relationship may be partially linked to thrombophilic genetic anomalies that may predispose to the progression of both diseases.

MATERIALS AND METHODS

We analyzed blood samples from 102 Lebanese patients with end-stage renal disease and undergoing hemodialysis and 20 randomly selected healthy volunteers for frequencies of 12 cardiovascular disease gene mutations and traditional risk factors. The frequencies of these mutations were calculated and compared in both groups. We stratified patients by quartiles according to their mean score of genetic mutations and traditional risk factors, as well as their mean age at dialysis initiation. Correlation analyses were performed on the various patient groups.

RESULTS

We observed a high frequency of mutations in patients on dialysis. Homozygous mutations (> 10% of patients) were observed in the PAI-1 (11%), MTHFR A1298C sequence variant (12.7%), and ACE genes (12%); in addition, the FXIII V34L and PAI-1 4G/5G genotypes were significantly associated with early dialysis initiation (P < .001 and P = .004, respectively). We observed a strong linear relationship between the different scores and age at dialysis initiation, with older patients exhibiting the highest genetic, traditional, and total scores versus those shown in the youngest patients (R2 = 0.72 and P < .001; R2 = 0.98 and P < .001; and R2 =0.96 and P < .001, respectively).

CONCLUSIONS

Our results revealed a polygenic thrombophilic profile in our population of Lebanese patients with end-stage renal disease. This profile showed a strong association between early dialysis initiation and specific homozygous cardiovascular disease gene mutations. The cumulative load of these genetic and traditional risk factors may be partly responsible for the increased risk of cardiovascular disease and risk of progression to end-stage renal disease in patients with chronic kidney disease.

Risk of female athlete triad development in Japanese collegiate athletes is related to sport type and competitive level

Introduction

Menstrual dysfunction, musculoskeletal injury, and poor nutrition combine to form the female athlete triad (FAT), which results in serious health consequences for affected athletes. To this point, the risk factors of this phenomenon have not been fully explored in Japanese female college athletes. Additionally, the effect of competitive level on FAT risk factors has also not been reported. Therefore, we aimed to examine FAT risk factors in Japanese female athletes of various sports as well as examine the impact of competitive level on FAT.

Methods

A Japanese-language survey was completed by 531 athletes and 20 nonathletes at two Japanese universities and answers with regard to menstrual status, musculoskeletal injury, nutrition, and other variables were analyzed based on classification of the sports into nine distinct groups based on activity type. Sport intensity, training volume, and competitive levels were used to further classify each sport. One-way ANOVA and the Bonferroni post hoc test using SPSS were carried out to analyze significance for relationships between sport intensity and FAT risk factors. Additionally, the relationship between competitive level and FAT risk factors was analyzed by ANOVA and Bonferroni post hoc tests.

Results

Sport intensity was positively correlated with a delay in menarche as well as dysmenorrhea and poor nutrition while musculoskeletal injury was correlated with repetitive, high-training volume sports. Lower competitive levels increased dysmenorrhea but did not impact injury status or nutrition.

Conclusion

Sport intensity and training volume, but not competitive level, are the critical factors affecting FAT risk in Japanese female college athletes.

The Effect of Swimming During Childhood and Adolescence on Bone Mineral Density: A Systematic Review and Meta-Analysis

BACKGROUND

The effects of swimming on bone mineral density (BMD) have been studied by several researchers, with inconsistent results.

AIM

This meta-analysis aims to determine whether systematic swimming training may influence BMD during childhood and adolescence.

METHODS

A systematic search was performed in PubMed, SPORTDiscus and ClinicalTrials.gov from the earliest possible year to March 2015, with data extraction and quality assessment performed independently by two researchers following the PRISMA methodology. Swimmers were compared to sedentary controls and to athletes performing highly osteogenic sports. Therefore, a total of two meta-analyses were developed.

RESULTS

Fourteen studies met the inclusion criteria and were included in the meta-analyses. Swimmers presented similar BMD values to sedentary controls and lower than other high-impact athletes. Femoral neck and lumbar spine BMD differences between swimmers and sedentary controls and between swimmers and athletes practicing osteogenic sports appeared to increase with age and favored the non-swimming groups. There were no differences by sex.

CONCLUSION

While swimming is associated with several health benefits, it does not appear to be an effective sport for improving BMD. Swimmers might be in need of additional osteogenic exercises for increasing BMD values.

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).

Are Elite Female Soccer Athletes at Risk for Disordered Eating Attitudes, Menstrual Dysfunction, and Stress Fractures?

OBJECTIVE

To determine the prevalence of stress fractures, menstrual dysfunction and disordered eating attitudes in elite female soccer athletes.

DESIGN

Cross-sectional descriptive study.

SETTING

Female soccer athletes were recruited from a national level youth soccer club, an NCAA Division I university team, and a women's professional team.

PARTICIPANTS

Two hundred twenty female soccer athletes with a mean age of 16.4 ± 4 years and BMI of 20.8 ± 2 kg/m(2) completed the study, representing all athletes from the included teams.

METHODS

One-time surveys completed by the athletes.

MAIN OUTCOME MEASUREMENTS

Height and weight were recorded, and body mass index (BMI) was calculated for each athlete. Athletes reported age of menarche, history of missing 3 or more menses within a 12-month period and stress fracture. The Eating Attitudes Test (EAT-26) was used to assess the athlete's body perception and attitudes toward eating.

RESULTS

Of the 220 soccer athletes, 3 athletes (1.6%) had a low BMI for their age, and 19 (8.6%) reported stress fractures of the lower extremity. Among athletes who had reached menarche, the average onset was 13 + 1 year; menstrual dysfunction were present in 21 (19.3%). On the EAT-26, 1 player scored in the high risk range (>20) and 17 (7.7%) scored in the intermediate risk range (10-19) for eating disorders. Athletes with an EAT-26 score ≥ 10 points had a significantly higher prevalence of menstrual dysfunction in the past year compared to athletes with an EAT-26 score of less than 10 (P = .02).

CONCLUSIONS

Elite female soccer athletes are susceptible to stress fractures and menstrual dysfunction and have delayed onset of menarche despite normal BMI and appropriate body perception and attitudes towards eating. Further studies are needed to better understand stress fracture risk in female soccer athletes and in other team sports to determine how these findings relate to long-term bone health in this population.

Effects of menarcheal age on the anterior cruciate ligament injury risk factors during single-legged drop landing in female artistic elite gymnasts

INTRODUCTION

Although numerous studies have demonstrated the relationship between maturation and lower extremity biomechanics during landing in team sport athletes, we are presently uninformed of any research that examined the single-legged drop landing biomechanics of gymnasts. The purpose of this study is to investigate the effects of the menarcheal age on the lower extremity biomechanics during a single-legged drop landing in female artistic elite gymnasts.

MATERIALS AND METHODS

Twenty-two female artistic elite gymnasts, between 9 and 36 years of age, participated in this study. The participants were divided into two groups pre- (n = 11) and post- (n = 11) menarche and asked to perform a single-legged drop landing on top of a 30 cm platform and land on a force plate. The statistical analysis consisted of the multivariate analysis with the level of significance set at p < 0.05.

RESULTS

The post-menarche group showed a decrease in their maximum knee flexion angle and increase in their maximum knee abduction angle, maximum internal tibial rotation angle, maximum knee abduction moment, and hamstring-quadriceps muscle activity ratio compared with the pre-menarche group during the single-legged drop landing.

CONCLUSIONS

The post-menarche group showed an increased noncontact anterior cruciate ligament injury risk, due to their greater knee loads, compared with the pre-menarche group.

Pubertal timing, bone acquisition, and risk of fracture throughout life

Pubertal maturation plays a fundamental role in bone acquisition. In retrospective epidemiological surveys in pre- and postmenopausal women, relatively later menarcheal age was associated with low bone mineral mass and increased risk of osteoporotic fracture. This association was usually ascribed to shorter time exposure to estrogen from the onset of pubertal maturation to peak bone mass attainment. Recent prospective studies in healthy children and adolescents do not corroborate the limited estrogen exposure hypothesis. In prepubertal girls who will experience later menarche, a reduced bone mineral density was observed before the onset of pubertal maturation, with no further accumulated deficit until peak bone mass attainment. In young adulthood, later menarche is associated with impaired microstructural bone components and reduced mechanical resistance. This intrinsic bone deficit can explain the fact that later menarche increases fracture risk during childhood and adolescence. In healthy individuals, both pubertal timing and bone development share several similar characteristics including wide physiological variability and strong effect of heritable factors but moderate influence of environmental determinants such as nutrition and physical activity. Several conditions modify pubertal timing and bone acquisition, a certain number of them acting in concert on both traits. Taken together, these facts should prompt the search for common genetic regulators of pubertal timing and bone acquisition. It should also open epigenetic investigation avenues to pinpoint which environmental exposure in fetal and infancy life, such as vitamin D, calcium, and/or protein supplies, influences both pubertal timing and bone acquisition.

Management of Low Bone Mass in Female Athletes

As female athletic participation has increased, the positive effects of exercise on health have become evident. However, with this growth in sports activity, a set of health problems unique to the female athlete has emerged. The female athlete triad and its components can occur in females of all ages in every sport. The Female Athlete Triad poses serious health risks, both short and long term, to the overall well-being of affected individuals. Sustained low energy availability can impair health, causing many medical complications within the skeletal, endocrine, cardiovascular, reproductive, and central nervous systems. With the surge of females participating in athletics within the past 10 to 15 years, it is both conceivable and likely that the prevalence of this syndrome will continue to grow. Therefore, it is imperative that appropriate screening and diagnostic measures are enacted by a multidisciplinary team of health care providers, counselors, teachers, and dieticians in order to provide the proper care to affected athletes. Initial awareness should take place within the educational confines of elementary and high schools. Screening for female athletes exhibiting risk factors for the triad should also take place at the time of sports physicals. If one component of the triad is identified, the clinician should take the time to effectively workup the other. Treatment for each component of the triad includes both pharmacological and nonpharmacological measures, with emphasis placed upon increased energy availability and overall improved nutritional health. Using this all-encompassing type of approach, sports medicine practitioners should feel empowered to continue to promote the lifelong well-being of female athletes in the years to come.

Role of intensive training in the growth and maturation of artistic gymnasts

Short stature and later maturation of youth artistic gymnasts are often attributed to the effects of intensive training from a young age. Given limitations of available data, inadequate specification of training, failure to consider other factors affecting growth and maturation, and failure to address epidemiological criteria for causality, it has not been possible thus far to establish cause–effect relationships between training and the growth and maturation of young artistic gymnasts. In response to this ongoing debate, the Scientific Commission of the International Gymnastics Federation (FIG) convened a committee to review the current literature and address four questions: (1) Is there a negative effect of training on attained adult stature? (2) Is there a negative effect of training on growth of body segments? (3) Does training attenuate pubertal growth and maturation, specifically, the rate of growth and/or the timing and tempo of maturation? (4) Does training negatively influence the endocrine system, specifically hormones related to growth and pubertal maturation? The basic information for the review was derived from the active involvement of committee members in research on normal variation and clinical aspects of growth and maturation, and on the growth and maturation of artistic gymnasts and other youth athletes. The committee was thus thoroughly familiar with the literature on growth and maturation in general and of gymnasts and young athletes. Relevant data were more available for females than males. Youth who persisted in the sport were a highly select sample, who tended to be shorter for chronological age but who had appropriate weight-for-height. Data for secondary sex characteristics, skeletal age and age at peak height velocity indicated later maturation, but the maturity status of gymnasts overlapped the normal range of variability observed in the general population. Gymnasts as a group demonstrated a pattern of growth and maturation similar to that observed among short-, normal-, late-maturing individuals who were not athletes. Evidence for endocrine changes in gymnasts was inadequate for inferences relative to potential training effects. Allowing for noted limitations, the following conclusions were deemed acceptable: (1) Adult height or near adult height of female and male artistic gymnasts is not compromised by intensive gymnastics training. (2) Gymnastics training does not appear to attenuate growth of upper (sitting height) or lower (legs) body segment lengths. (3) Gymnastics training does not appear to attenuate pubertal growth and maturation, neither rate of growth nor the timing and tempo of the growth spurt. (4) Available data are inadequate to address the issue of intensive gymnastics training and alterations within the endocrine system.

Female athlete triad and its components: toward improved screening and management

As female athletic participation has increased, the positive effects of exercise on health have become evident. However, with this growth in sports activity, a set of health problems unique to the female athlete has emerged. The female athlete triad as first described in 1992 by the American College of Sports Medicine consisted of disordered eating, amenorrhea, and osteoporosis; the definition was updated in 2007 to include a spectrum of dysfunction related to energy availability, menstrual function, and bone mineral density. For this review, a comprehensive search of databases-MEDLINE In-Process & Other Non-Indexed Citations, MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, and Scopus, from earliest inclusive dates to January 2013-was conducted by an experienced librarian with input from the authors. Controlled vocabulary supplemented with keywords such as female athlete triad, amenorrhea, oligomenorrhea, fracture, osteopenia, osteoporosis, bone disease, anorexia, bulimia, disordered eating, low energy availability was used to search for articles on female athlete triad. Articles addressing the prevalence, screening, and management of the female athlete triad were selected for inclusion in the review. This article reviews the current definitions of the triad components, epidemiology, pathophysiology, and recommended screening and management guidelines. The lack of efficacy of current screening of athletes is highlighted. Low energy availablity, from either dietary restriction or increased expenditure, plays a pivotal role in development of the triad. Athletes involved in "lean sports" (those that emphasize weight categories or aesthetics, such as ballet, gymnastics, or endurance running) are at highest risk. Treatment is centered on restoring energy availability to reverse adverse changes in the metabolic milieu. Prevention and early recognition of triad disorders are crucial to ensure timely intervention. Caregivers and physicians of female athletes must remain vigilant in education, recognition, and treatment of athletes at risk.

Former premenarcheal gymnasts exhibit site-specific skeletal benefits in adulthood after long-term retirement

Young female gymnasts have greater bone strength compared to controls; although possibly due to selection into gymnastics, it is thought that their loading activity during growth increases their bone mass, influencing both bone geometry and architecture. If such bone mass and geometric adaptations are maintained, this may potentially decrease the risk of osteoporosis and risk of fracture later in life. However, there is limited evidence of the persisting benefit of gymnastic exercise during growth on adult bone geometric parameters. Therefore, the purpose of this study was to determine whether adult bone geometry, volumetric density, and estimated strength were greater in retired gymnasts compared to controls, 10 years after retirement from the sport. Bone geometric and densitometric parameters, measured by peripheral quantitative computed tomography (pQCT) at the radius and tibia, were compared between 25 retired female gymnasts and 22 controls, age range 22 to 30 years, by multivariate analysis of covariance (covariates: age, height, and muscle cross-sectional area). Retired gymnasts had significantly greater adjusted total and trabecular area (16%), total and trabecular bone mineral content (BMC) (18% and 22%, respectively), and estimated strength (21%) at the distal radius (p < 0.05) than controls. Adjusted total and cortical area and BMC, medullary area, and estimated strength were also significantly greater (13% to 46%) in retired gymnasts at the 30% and 65% radial shaft sites (p < 0.05). At the distal tibia, retired gymnasts had 12% to 13% greater total and trabecular BMC and volumetric bone mineral density as well as 21% greater estimated strength; total and cortical BMC and estimated strength were also greater at the tibial shaft (8%, 11%, and 10%, respectively) (p < 0.05). Former female gymnasts have significantly better geometric and densitometric properties, as well as estimated strength, at the radius and tibia 10 years after retirement from gymnastics compared to females who did not participate in gymnastics in childhood and adolescence.

Professor James M. Tanner and the sport sciences

BACKGROUND

Although Tanner was not directly involved in physical education or the sport sciences, several of his papers addressed issues related to research in the area.

AIM

To consider the implications of selected papers and research projects for the sport sciences. PAPERS AND IMPLICATIONS: Several early papers addressed ratio standards, somatotype and total cholesterol, and anthropometric and somatotype changes associated weight training and cessation of training in young adult men. The papers have, respectively, implications for current studies of allometric scaling, physique and risk factors for cardiovascular and metabolic complications, and responses to training. The survey of athletes at the 1960 Rome Olympic Games not only added to the literature but to some extent also set the stage for subsequent surveys of Olympic athletes in 1968, 1972 and 1976. Although not directly involved in the mixed-longitudinal study of Training of Youth Athletes (TOYA) in several sports, it was conducted in his department. Results from TOYA indicated no influence of systematic training for sport on growth in height, young adult height and sexual maturation. Growth at Adolescence was also a fixture in many graduate programs.

CONCLUSION

Though not a sport scientist, Tanner contributed directly and indirectly to the field.

Higher premenarcheal bone mass in elite gymnasts is maintained into young adulthood after long-term retirement from sport: a 14-year follow-up

Sports that impact-load the skeleton during childhood and adolescence increase determinants of bone strength such as bone mineral content and density; however, it is unclear if this benefit is maintained after retirement from the sport. The purpose of this study was to assess whether the previously reported higher bone mass in a group of premenarcheal gymnasts was still apparent 10 years after the cessation of participation and withdrawal of the gymnastics loading stimulus. In 1995, 30 gymnasts 8 to 15 years of age were measured and compared with 30 age-matched nongymnasts. Twenty-five former gymnasts and 22 nongymnasts were measured again 14 years later (2009 to 2010). Gymnasts had been retired from gymnastics training and competition for an average of 10 years. Total body (TB), lumbar spine (LS), and femoral neck (FN) bone mineral content (BMC) was assessed at both measurement occasions by dual-energy X-ray absorptiometry (DXA). Multivariate analysis of covariance (MANCOVA) was used to compare former gymnasts' and nongymnasts' BMC while controlling for differences in body size and maturation (covariates: age, height, weight, and years from menarche [1995] or age at menarche [2009 to 2010]). Premenarcheal gymnasts (measured in 1995) had significantly greater size-adjusted TB, LS, and FN BMC (p < 0.05) (15%, 17%, and 12%, respectively) than nongymnasts. Ten years after retirement, gymnasts had maintained similar size-adjusted TB, LS, and FN BMC differences (p < 0.05) (13%, 19%, and 13%, respectively) when compared with nongymnasts. Bone mass benefits in premenarcheal gymnasts were still apparent even after long-term (10 years) removal of the gymnastics loading stimulus.

Pubertal timing and body mass index gain from birth to maturity in relation with femoral neck BMD and distal tibia microstructure in healthy female subjects

Childhood body mass index (BMI) gain is linked to hip fracture risk in elderly. In healthy girls, menarcheal age is inversely related to BMI gain during childhood and to femoral neck areal bone mass density (aBMD) and distal tibia structural components at maturity. This study underscores the importance of pubertal timing in age-related fragility fracture risk.

INTRODUCTION

Recent data point to a relationship between BMI change during childhood and hip fracture risk in later life. We hypothesized that BMI development is linked to variation in pubertal timing as assessed by menarcheal age (MENA) which in turn, is related to peak bone mass (PBM) and hip fracture risk in elderly.

METHODS

We studied in a 124 healthy female cohort the relationship between MENA and BMI from birth to maturity, and DXA-measured femoral neck (FN) aBMD at 20.4 year. At this age, we also measured bone strength related microstructure components of distal tibia by HR-pQCT.

RESULTS

At 20.4 ± 0.6 year, FN aBMD (mg/cm(2)), cortical thickness (μm), and trabecular density (mg HA/cm(3)) of distal tibia were inversely related to MENA (P = 0.023, 0.015, and 0.041, respectively) and positively to BMI changes from 1.0 to 12.4 years (P = 0.031, 0.089, 0.016, respectively). Significant inverse (P < 0.022 to <0.001) correlations (R = -0.21 to -0.42) were found between MENA and BMI from 7.9 to 20.4 years, but neither at birth nor at 1.0 year. Linear regression indicated that MENA Z-score was inversely related to BMI changes not only from 1.0 to 12.4 years (R = -0.35, P = 0.001), but also from 1.0 to 8.9 years, (R = -0.24, P = 0.017), i.e., before pubertal maturation.

CONCLUSION

BMI gain during childhood is associated with pubertal timing, which in turn, is correlated with several bone traits measured at PBM including FN aBMD, cortical thickness, and volumetric trabecular density of distal tibia. These data complement the reported relationship between childhood BMI gain and hip fracture risk in later life.

Familial concordance for age at menarche: analyses from the Breakthrough Generations Study

Age at menarche is correlated within families, but estimates of the heritability of menarcheal age have a wide range (0.45-0.95). We examined the familial resemblance for age at menarche and the extent to which this is due to genetic and shared environmental factors. Between 2003 and 2010 data were retrospectively collected by questionnaire from participants within the UK-based Breakthrough Generations Study. These analyses included 25,970 female participants aged 16-98 with at least one female relative who was also a study participant. A woman's menarche was significantly delayed for each yearly increase in the menarcheal age of her monozygotic twin (average increase = 7.2 months, P < 0.001), dizygotic twin (average increase = 3.0 months, P = 0.03), older sister (average increase = 3.3 months, P < 0.001), mother (average increase = 3.4 months, P < 0.001), maternal grandmother (average increase = 1.5 months, P = 0.04), maternal aunt (average increase = 1.4 months, P < 0.001) and paternal aunt (average increase = 3.0 months, P < 0.001). There was not a significant association between the menarcheal ages of half-sister pairs or of paternal grandmother-granddaughter pairs, based on small numbers. Heritability was estimated as 0.57 [95% confidence interval 0.53, 0.61]. Shared environmental factors did not have an effect in the model. In conclusion, approximately half of the variation in age at menarche was attributable to additive genetic effects with the remainder attributable to non-shared environmental effects.

The influence of intensive physical training on growth and pubertal development in athletes

Genetic potential for growth can be fully expressed only under favorable environmental conditions. Although moderate physical activity has beneficial effects on growth, excessive physical training may negatively affect it. Sports favoring restricted energy availability, in the presence of high energy expenditure, are of particular concern. In gymnastics, a different pattern in skeletal maturation and linear growth was observed, resulting in an attenuation of growth potential in artistic gymnasts (AG), more pronounced in males than in females. In female rhythmic gymnasts (RG), the genetic predisposition to growth was preserved owing to a late catchup growth phenomenon. In all other sports not requiring strict dietary restrictions, no deterioration of growth has been documented so far. Intensive physical training and negative energy balance alter the hypothalamic pituitary set point at puberty, prolong the prepubertal stage, and delay pubertal development and menarche in a variety of sports. In elite RG and AG, prepubertal stage is prolonged and pubertal development is entirely shifted to a later age, following the bone maturation rather than the chronological age.

Talent identification and promotion programmes of Olympic athletes

The start of a new Olympic cycle offers a fresh chance for individuals and nations to excel at the highest level in sport. Most countries attempt to develop systematic structures to identify gifted athletes and to promote their development in a certain sport. However, forecasting years in advance the next generation of sporting experts and stimulating their development remains problematic. In this article, we discuss issues related to the identification and preparation of Olympic athletes. We provide field-based data suggesting that an earlier onset and a higher volume of discipline-specific training and competition, and an extended involvement in institutional talent promotion programmes, during adolescence need not necessarily be associated with greater success in senior international elite sport. Next, we consider some of the promising methods that have been (recently) presented in the literature and applied in the field. Finally, implications for talent identification and promotion and directions for future research are highlighted.

History of amenorrhoea compromises some of the exercise-induced benefits in cortical and trabecular bone in the peripheral and axial skeleton: a study in retired elite gymnasts

BACKGROUND

Female gymnasts frequently present with overt signs of hypoestrogenism, such as late menarche or menstrual dysfunction. The objective was to investigate the impact of history of amenorrhoea on the exercise-induced skeletal benefits in bone geometry and volumetric density in retired elite gymnasts.

SUBJECTS AND METHODS

24 retired artistic gymnasts, aged 17-36 years, who had been training for at least 15 h/week at the peak of their career and had been retired for 3-18 years were recruited. They had not been engaged in more than 2 h/week of regular physical activity since retirement. Former gymnasts who reported history of amenorrhoea ('AME', n=12: either primary or secondary amenorrhoea) were compared with former gymnasts ('NO-AME', n=12) and controls ('C', n=26) who did not report history of amenorrhoea. Bone mineral content (BMC), total bone area (ToA) and total volumetric density (ToD) were measured by pQCT at the radius and tibia (4% and 66%). Trabecular volumetric density (TrD) and bone strength index (BSI) were measured at the 4% sites. Cortical area (CoA), cortical thickness (CoTh), medullary area (MedA), cortical volumetric density (CoD), stress-strain index (SSI) and muscle and fat area were measured at the 66% sites. Spinal BMC, areal BMD and bone mineral apparent density (BMAD) were measured by DXA.

RESULTS

Menarcheal age was delayed in AME when compared to NO-AME (16.4+/-0.5 years vs. 13.3+/-0.4 years, p<0.001). No differences were detected between AME and C for height-adjusted spinal BMC, aBMD and BMAD, TrD and BSI at the distal radius and tibia, CoA at the proximal radius, whereas these parameters were greater in NO-AME than C (p<0.05-0.005). AME had lower TrD and BSI at the distal radius, and lower spinal BMAD than NO-AME (p<0.05) but they had greater ToA at the distal radius (p<0.05).

CONCLUSION

Greater spinal BMC, aBMD and BMAD as well as trabecular volumetric density and bone strength in the peripheral skeleton were found in former gymnasts without a history of menstrual dysfunction but not in those who reported either primary or secondary amenorrhoea. History of amenorrhoea may have compromised some of the skeletal benefits associated with high-impact gymnastics training.

The influence of dance training on growth and maturation of young females: A mixed longitudinal study

BACKGROUND

The effects of systematic sports training during childhood and adolescence on subsequent growth and sexual maturation remains in dispute.

AIM

The study aimed to determine whether moderate-high volumes of dance training adversely influence linear growth and sexual maturation of young girls progressing through puberty.

SUBJECTS AND METHODS

This 3-year mixed longitudinal study comprised 82 novice dancers and 61 controls, aged 8-11 years at baseline, who were assessed bi-annually for 3 consecutive years. A biological maturational age was determined by estimating attainment of age at peak height velocity (PHV). Body dimensions were measured by anthropometry, and exercise levels, nutritional intake and age at menarche by questionnaires.

RESULTS

Controls had significantly greater unadjusted height velocity than dancers 1 year before PHV, however there was no difference between groups in age of attainment of PHV. When controlling for maturation, lean mass, fat mass and extracurricular sport (excluding dancing), there were no group differences in absolute growth or velocity of growth in height, sitting height or leg length. Within the dancers there were no effects of years of dancing (>6.5 years) or weekly dance hours (>7 h per week) on growth velocities. No association was found between age at menarche and years or hours of dance training.

CONCLUSION

Results suggest that moderate-high levels of dance training do not affect linear growth and maturation. Thus, girls should not be discouraged from dance participation on the basis of potential growth delays.

Deleterious effect of late menarche on distal tibia microstructure in healthy 20-year-old and premenopausal middle-aged women

Late menarche is a risk factor for fragility fractures. We hypothesized that pubertal timing-dependent alterations in bone structural components would persist from peak bone mass to menopause, independent of premenopausal bone loss. We studied the influence of menarcheal age (MENA) on femoral neck BMD (FN aBMD) by DXA and microstructure of distal tibia by HR-pQCT in healthy young adult (YAD; 20.4 +/- 0.6 [SD] yr, n = 124) and premenopausal middle-aged (PREMENO; 45.8 +/- 3.4 yr, n = 120) women. Median of MENA was 13.0 +/- 1.2 and 13.1 +/- 1.7 yr in YAD and PREMENO, respectively. In YAD and PREMENO (n = 244), FN aBMD (R = -0.29, p = 0.013), as well as total volumetric BMD (Dtot; R = -0.23, p = 0.006) and cortical thickness (Ct.Th; R = -0.18, p = 0.011) of distal tibia were inversely correlated to MENA. After segregation by the median of MENA in EARLY and LATE subgroups, the significant influences of both MENA (p = 0.004) and chronological age (p < 0.0001) were observed for FN aBMD and trabecular bone volume fraction of the distal tibia with similar differences in T-scores between LATE and EARLY subgroups in YAD (-0.36 and -0.31 T-scores) and PREMENO (-0.35 and -0.42 T-scores) women. Ct.Th was negatively influenced by MENA, whereas trabecular thickness (Tb.Th) was negatively influenced by chronological age. There was a striking inverse relationship between cross-sectional area and Ct.Th (R = -0.57, p < 0.001). In conclusion, the negative influence of late menarcheal age at weight-bearing sites as observed by the end of skeletal growth remains unattenuated a few years before menopause and is independent of premenopausal bone loss. Alterations in both bone mineral mass and microstructural components may explain the increased risk of fragility fractures associated with later menarcheal age.

Age at menarche and the risk of breast cancer in BRCA1 and BRCA2 mutation carriers

Age at menarche is a strong and consistent predictor of breast cancer risk in the general population, but has not been well studied in women with a family history of breast cancer. We conducted this study to examine whether the presence of a deleterious BRCA1 or BRCA2 mutation influences age at menarche and to investigate whether or not there is an association between age at menarche and the risk of breast cancer in BRCA1 or BRCA2 mutation carriers. The presence of a deleterious BRCA1 or BRCA2 mutation did not appear to influence a woman's age at menarche. A matched case-control study was conducted on 1311 pairs of women who have been identified to be carriers of a deleterious mutation in either the BRCA1 (n = 945 pairs) or the BRCA2 gene (n = 366 pairs). Information about age at menarche was derived from a questionnaire routinely administered to carriers of a mutation in either gene. Among women who carried a deleterious BRCA1 mutation, age at menarche was inversely associated with the risk of breast cancer (p trend = 0.0002). This association was not observed among BRCA2 mutation carriers (p trend = 0.49). Compared with BRCA1 carriers whose age at menarche was < or =11 years, women with a menarcheal age between 14 and 15 years old had a 54% reduction in risk (OR = 0.46; 95% CI 0.30-0.69). This study implicates early age at menarche as a determinant of breast cancer among women with a BRCA1 mutation.

Participation in leanness sports but not training volume is associated with menstrual dysfunction: a national survey of 1276 elite athletes and controls

OBJECTIVE

To examine the prevalence of menstrual dysfunction in the total population of Norwegian elite female athletes and national representative controls in the same age group.

METHODS

A detailed questionnaire that included questions on training and/or physical activity patterns, menstrual, dietary, and weight history, oral contraceptive use, and eating disorder inventory subtests was administered to all elite female athletes representing the country at the junior or senior level (aged 13-39 years, n = 938) and national representative controls in the same age group (n = 900). After exclusion, a total of 669 athletes (88.3%) and 607 controls (70.2%) completed the questionnaire satisfactorily.

RESULTS

Age at menarche was significantly (p<0.001) later in athletes (13.4 (1.4) years) than in controls (13.0 (1.3) years), and differed among sport groups. A higher percentage of athletes (7.3%) than controls (2.0%) reported a history of primary amenorrhoea (p<0.001). A similar percentage of athletes (16.5%) and controls (15.2%) reported present menstrual dysfunction, but a higher percentage of athletes competing in leanness sports reported present menstrual dysfunction (24.8%) than athletes competing in non-leanness sports (13.1%) (p<0.01) and controls (p<0.05).

CONCLUSIONS

These novel data include virtually all eligible elite athletes, and thus substantially extend previous studies. Age at menarche occurred later and the prevalence of primary amenorrhoea was higher in elite athletes than in controls. A higher percentage of athletes competing in sports that emphasise thinness and/or a specific weight reported present menstrual dysfunction than athletes competing in sports focusing less on such factors and controls. On the basis of a comparison with a previous study, the prevalence of menstrual dysfunction was lower in 2003 than in 1993.

Alterations in serum growth hormone (GH)/GH dependent ternary complex components (IGF-I, IGFBP-3, ALS, IGF-I/IGFBP-3 molar ratio) and the influence of these alterations on growth pattern in female rhythmic gymnasts

BACKGROUND AND AIM

Normal growth in children is regulated to a great extent through the actions of the GH/IGF-I axis, a system consisting of GH and its mediators (ternary complex) that modulate growth in many tissues. The ternary complex (IGF-I/IGFBP-3/ALS) provides an acute regulatory mechanism in which IGF-I may be mobilized from the circulating reservoir of 150 kDa complexes to the tissues. Acute exercise is known to be a stimulus for GH secretion. The beneficial effects of scheduled exercise on body composition are also well established. However, the impact of strenuous exercise on the pubertal development of child athletes is still not well understood. The first goal of this study was to assess the acute effects of high intensity exercise training on GH-dependent ternary complex components in female rhythmic gymnasts compared to age-matched healthy female controls with normal physical activity. The second goal was to explore the influence of these exercise-induced changes on skeletal and pubertal growth in the same group prospectively over a period of 4 years.

SUBJECTS AND METHODS

Seventeen female rhythmic gymnasts, aged 11.4 +/- 0.9 years, who had 10 h per week intense exercise for at least 4 months volunteered to participate in this study. Anthropometric measurement of height (Height SDS for chronological age [HtSDS(CA)], parentally adjusted height, predicted adult height), bone age and weight (BMI) were made using standard techniques in gymnasts and controls (aged 12.5 +/- 3.0 years, n = 12). Gymnasts were followed up to 4 years to observe growth velocity and pubertal progression. In order to determine the acute impact of exercise on levels of GH and GH-dependent ternary complex component (IGF-I, IGFBP-3, ALS, IGF-I/IGFBP-3 molar ratio), blood samples were obtained from gymnasts after a routine 2-h high-intensity training program and then after a 2-day rest period. These results were compared with age-matched controls with no scheduled sports activity.

RESULTS

Despite the significant increment in serum GH and GH-dependent components immediately following the exercise, serum GH/IGF-I levels showed a significant decrement (p < 0.01) after a 2-day rest in gymnasts, to a nadir as low as those of the control subjects' baseline levels (p < 0.01). There was no difference in anthropometric characteristics of gymnasts and controls except BMI; gymnasts were leaner than controls. During a 4-year follow up, there were no differences between the gymnasts and controls in regard to skeletal growth and reaching their predicted height. However, in gymnasts there was a delay in pubertal tempo but not in growth.

CONCLUSION

Intense exercise induces an acute rise in GH levels, but this acute elevation rapidly normalizes after a 2-day rest in female rhythmic gymnasts. These fluctuations in serum GH and GH-dependent ternary complex components had no reflection on the skeletal growth patterns in gymnasts over the 4-year follow up but there was a delay in their pubertal progression.

Growth at puberty

Somatic growth and maturation are influenced by a number of factors that act independently or in concert to modify an individual's genetic potential. The secular trend in height and adolescent development is further evidence for the significant influence of environmental factors on an individual's genetic potential for linear growth. Nutrition, including energy and specific nutrient intake, is a major determinant of growth. Paramount to normal growth is the general health and well-being of an individual; in fact, normal growth is a strong testament to the overall good health of a child. More recently the effect of physical activity and fitness on linear growth, especially among teenage athletes, has become a topic of interest. Puberty is a dynamic period of development marked by rapid changes in body size, shape, and composition, all of which are sexually dimorphic. One of the hallmarks of puberty is the adolescent growth spurt. Body compositional changes, including the regional distribution of body fat, are especially large during the pubertal transition and markedly sexually dimorphic. The hormonal regulation of the growth spurt and the alterations in body composition depend on the release of the gonadotropins, leptin, the sex-steroids, and growth hormone. It is very likely that interactions among these hormonal axes are more important than their main effects, and that alterations in body composition and the regional distribution of body fat actually are signals to alter the neuroendocrine and peripheral hormone axes. These processes are merely magnified during pubertal development but likely are pivotal all along the way from fetal growth to the aging process.

Alterações hormonais da mulher atleta

O propósito desta revisão é focalizar o exercício como modulador da reprodução humana, resumir e integrar os dados atuais referentes ao eixo hipotálamo-hipófise-gonadal na mulher atleta. A prevalência de disfunção menstrual, tal como fase lútea deficiente, oligomenorréia, amenorréia e retardo puberal, é maior entre o grupo de mulheres atletas quando comparado à população geral. Vários fatores podem predispor e contribuir para o desenvolvimento das irregularidades menstruais durante o programa de atividade física, sendo considerados fatores de risco, entre eles, baixo peso, teor de gordura corporal e estados hipoestrogênicos. O hipoestrogenismo pode afetar o pico de massa óssea na puberdade e acarretar perda óssea prematura irreversível. O artigo revisa os efeitos fisiológicos do treinamento físico nos vários sistemas endócrinos e aborda informações clínicas a respeito dos distúrbios hormonais específicos da mulher atleta.

The missing politics and unsettled science of the trend toward earlier puberty

The age of puberty in many populations has declined steeply over recent centuries and may be declining still. Consequently, today's children tend to experience the hormonal stresses of rapid development at younger ages than did their ancestors, around whose later, if not more gradual, maturation traditional behavioral expectations formed. Little has been made of this "rush to puberty" outside the life sciences. This article reviews its historical documentation, scholarly appreciation, epidemiological correlations, putative physiological and environmental explanations, sociological implications, and largely latent politics.

Growth and pubertal development in children and adolescents: effects of diet and physical activity

The longitudinal growth of an individual child is a dynamic statement of the general health of that child. Measurements should be performed often and accurately to detect alterations from physiologic growth. Although any single point on the growth chart is not very informative, when several growth points are plotted over time, it should become apparent whether that individual's growth is average, a variant of the norm, or pathologic. Somatic growth and maturation are influenced by several factors that act independently or in concert to modify an individual's genetic growth potential. Linear growth within the first 2 y of life generally decelerates but then remains relatively constant throughout childhood until the onset of the pubertal growth spurt. Because of the wide variation among individuals in the timing of the pubertal growth spurt, there is a wide range of physiologic variations in normal growth. Nutritional status and heavy exercise training are only 2 of the major influences on the linear growth of children. In the United States, nutritional deficits result from self-induced restriction of energy intake. That single factor, added to the marked energy expenditure of training and competition for some sports, and in concert with the self-selection of certain body types, makes it difficult to identify the individual factors responsible for the slow linear growth of some adolescent athletes, for example, those who partake in gymnastics, dance, or wrestling.

Growth and pubertal development in elite female rhythmic gymnasts

Optimal growth depends upon both environmental and genetic factors. Among environmental factors that could alter growth and sexual maturation are stress and intensive physical training. The influence of these factors has been documented in a variety of sports, but there is limited information on rhythmic gymnasts, who have entirely different training and performance requirements. The study was conducted during the 13th European Championships in Patras, Greece, and included 255 female rhythmic gymnasts, aged 11-23 yr. The study included measurement of height and weight, assessment of breast and pubic hair development, estimation of body fat and skeletal maturation, and registration of menarcheal age and parental height. Gymnasts were taller than average height for age, with mean height above and mean weight below the 50th percentile. Actual height SD score was positively correlated to weight SD score (P < 0.001), number of competitions (P = 0.01), and body mass index (BMI; P < 0.001). Predicted adult height SD score was positively correlated to weight SD score (P < 0.001) and negatively to body fat (P = 0.004). There was a delay in skeletal maturation of 1.3 yr (P < 0.001). Pubertal development was following bone age rather than chronological age. The mean age of menarche was significantly delayed from that of their mothers and sisters (P = 0.008 and P = 0.05, respectively), was positively correlated to the intensity of training and to the difference between chronological age and bone age (P < 0.001 and P = 0.002, respectively), and was negatively correlated to body fat (P < 0.001). In the elite female rhythmic gymnasts, psychological and somatic efforts have profound effects on growth and sexual development. Despite these aberrations, adult height is not expected to be affected.

Determinants of age at menarche as early life predictors of breast cancer risk

Age at menarche is one of the few established risk factors for breast cancer; identification of its exogenous determinants could throw light on the origins of breast cancer. We have undertaken an epidemiologic study in Greece to ascertain whether: 1) energy intake, an indicator of physical activity, is associated with later age at menarche; 2) energy-adjusted fat intake is related to earlier age at menarche; and 3) other macronutrients and anthropometric variables are predictors of age at menarche. Anthropometric, socio-economic, familiar, nutritional and lifestyle predictors of age at menarche were studied by interviewing in person 345 female students 9 to 16 years old attending 8 schools of Greater Athens. Menarche was the outcome variable in a proportional hazards model assessing the mutually adjusted incidence rate ratio by a series of predictor variables. In a complementary analysis, age at menarche was the dependent variable among menstruating girls. Consistent results were derived from the main and the complementary analysis. Increased height and body mass index accelerate the occurrence of menarche. Maternal and daughter's ages at menarche are correlated, but there is no evidence of an association with paternal education. Various measures of moderate physical activity as well as increased total energy intake were associated with a delay in age at menarche. Energy-adjusted macronutrients were not associated with age at menarche. It appears that an alteration of energy balance in early life through increased physical activity could delay age at menarche and reduce the risk for breast cancer in later life.

Growth and development of male gymnasts, swimmers, soccer and tennis players: a longitudinal study

Elite adult athletes are known to have physical and physiological characteristics specifically suited to their sport. However, it is not clear whether the observed adult differences arise because of training or whether the sport selects the individual with the appropriate characteristics. The purpose of this prospective study was to compare and contrast the physical development of young athletes (8-19 years), and in so doing provide a possible response to this question. Development of anthropometric characteristics and sexual maturation were assessed in a group of 232 male athletes for three consecutive years. Parental heights were used to predict target heights. The subjects were a randomly selected group of young British athletes, from four sports: soccer, gymnastics, swimming and tennis. Using a linked longitudinal cohort study design (age cohorts 8, 10, 12, 14 and 16 years) it was possible to estimate a consecutive 11-year development pattern, over the 3-year testing period. The adjusted mean (ANCOVA) height, accounting for age and pubertal status, of male swimmers (161.6 +/- 0.6 cm) was found to be significantly greater (p < 0.01) than gymnasts (150.7 +/- 0.8 cm) and soccer players (158.7 +/- 0.6 cm), and their adjusted mean body mass (51.3 +/- 0.6 kg) significantly greater (p < 0.01) than the other groups. When testicular volumes were compared, it was found that swimmers had significantly larger volumes than gymnasts and tennis players from 14 to 16 years of age (p < 0.05). Gymnasts' growth curve of testis size was characteristic of late maturers, the swimmers' curve was characteristic of early maturers. As all the young athletes started training prior to puberty the observed late sexual maturation of gymnasts and early maturation of swimmers suggests some form of sports-specific selection. Training did not appear to have affected these young athletes' growth and development; rather their continued success in sport appeared to be related to inherited traits.