An Evolutionary Psychology Perspective on Athletic Development and Performance: Differences Between Proximate and Ultimate Explanations

Many areas of mainstream psychology have embraced the notions that understanding human behaviour can be improved by integrating developments from evolutionary science; however, evolutionary principles have not been as widely applied among sport researchers or practitioners, especially those examining athlete development and the psychology of competition and performance. In this paper, we discuss the distinction between ultimate and proximate explanations of psychological outcomes, and the relevance of this distinction for exploring issues related to skill acquisition and athlete development. We use three examples-deliberate practice, early sport play and sustained engagement-to highlight the benefits and challenges of applying evolutionary theories to sport contexts. Embracing our species' evolutionary history has the potential to inform ongoing debates in athlete development and performance, among other areas of sport science.

Exploratory Study into the Classification Agreement between Self-Reported Age of Menarche and Calculated Maturity Offset in Adolescent Girls: A Two-Year Follow-Up Study

Menarche is a significant pubertal event influencing girls' participation in physical activity. As menarche is a sensitive matter, a non-invasive substitute is needed to help classify girls' maturity status and provide physical literacy to them in this regard. The objective of this exploratory study was to investigate the classification agreement between self-reported age of menarche and calculated maturity offset in adolescent girls from South Africa by making use of various statistical methods. Fifty-eight girls, n = 13 pre- and n = 45 post-menarche (Status Quo method) aged 13.51 ± 3.51 years at baseline, were analyzed (2010-2012). Independent t-testing, cross-tabulation, Roc Curve statistics and logistic regression were used to analyze the classification agreement between markers. All four statistical methods revealed the potential to categorize different maturity groups through the maturity offset equation, although the accuracy declined with increased age. A realized power of 0.92 was found for the group in the first year of the study, with a gradual and significant decline over time. Cross-tabs showed a significant moderate predictive effectiveness (Chi-square = 0.042) during T1, closer to PHV (13.51 years) although also declining significantly with increased age (T2, 14.51 years) beyond PHV (Chi-square = 0.459). Although positive results were found, caution must be used when using maturity offset equations in different homogenic populations due to their unique growth characteristics.

Meta-analysis of genomic variants in power and endurance sports to decode the impact of genomics on athletic performance and success

Association between genomic variants and athletic performance has seen a high degree of controversy, as there is often conflicting data as far as the association of genomic variants with endurance, speed and strength is concerned. Here, findings from a thorough meta-analysis from 4228 articles exploring the association of genomic variants with athletic performance in power and endurance sports are summarized, aiming to confirm or overrule the association of genetic variants with athletic performance of all types. From the 4228 articles, only 107 were eligible for further analysis, including 37 different genes. From these, there were 21 articles for the ACE gene, 29 articles for the ACTN3 gene and 8 articles for both the ACE and ACTN3 genes, including 54,382 subjects in total, from which 11,501 were endurance and power athletes and 42,881 control subjects. These data show that there is no statistically significant association between genomic variants and athletic performance either for endurance or power sports, underlying the fact that it is highly risky and even unethical to make such genetic testing services for athletic performance available to the general public. Overall, a strict regulatory monitoring should be exercised by health and other legislative authorities to protect the public from such services from an emerging discipline that still lacks the necessary scientific evidence and subsequent regulatory approval.

Patterns of Movement Performance among Japanese Children and Effects of Parenting Practices: Latent class analysis

Objectives

This study aimed to examine the long-term effects of parenting practice during preschool years on children's movement performance in primary school.

Methods

This three-year longitudinal study included 225 children aged 3-6-years-old. Parents reported baseline parenting practice and evaluated children's movement performance three years later. Latent class analysis was used to explore latent classes of movement performance. A post hoc test was used to identify the characteristics of different patterns. Finally, adjusted multinomial logistic regression models were used to test the influence of parenting practice on identified patterns of movement performance.

Results

Children in this study were grouped into three movement performance patterns, labelled as 'least difficulties' (n = 131, 58.2%), 'low back pain' (n = 68, 30.2%) and 'most difficulties' (n = 26, 11.6%). After controlling for age, gender, having siblings or not, family structure, standardised body mass index, sleep condition and dietary habits, the researchers found that if parents played games with children frequently, the children would have a 0.287 times lower probability of being in the 'low back pain' class (95% confidence interval [CI]: 0.105-0.783). In addition, if parents take children to meet peers of a similar age frequently, children would have a 0.339 times lower probability of being in 'most difficulties' class (95% CI: 0.139-0.825).

Conclusion

Primary healthcare providers should pay careful attention to children with movement difficulties. The study provides longitudinal evidence to support the applicability of positive parenting practice in early childhood to prevent children's movement difficulties.

Application of the Motor Abilities Assessment as Part of a Talent Identification System in Tennis Players: A Pilot Study

In this study, we sought to develop a testing system to scientifically identify tennis talent. This testing system will provide helpful information for players who intend to pursue a professional tennis career. The experimental subjects were 18 college students consisting of 10 tennis players (including 4 soft tennis) and 8 basketball players (all males). The subjects were tested on their vertical jump, 60 m shuttle runs, and shoulder joint mobility to identify tennis talent. To statistically analyze the data, an R package was used to conduct a principal component analysis of the athletic performance indicators of the samples, and the samples were further classified via agglomerative hierarchical clustering. This study found that tennis players required more flexibility than basketball players. Regarding the differences between male and female soft tennis players, the unclassified results showed that there was a significant difference in explosive power. However, there was no significant difference in flexibility between genders. The research methods and results of this study can be used as a reference for others to build a system for identifying athletic performance characteristics in the future, and it is expected that the implementation of this system can provide sports coaches with more information for talent selection and improve the accuracy of their judgments, allowing athletes to play to their strengths.

Bounded Rationality and Heuristics: Do We Only Need to Score in Order to Win Individual Awards in Basketball?

In the game of basketball game-related statistics are utilised to help decision makers to evaluate players’ achievements. Previous research showed that in the case of individual awards, points are preferred over other indicators of effectiveness. Based on recent studies and following Simon’s bounded rationality, in our interpretation, decision-makers decide on nominations at the post-grant level according to points scoring which is the easiest aspect to assess and the most familiar to them. In this context we also hypothesise that youth all-star players have better overall performance than their not selected teammates. To test our hypotheses we selected all of the youth awarded male players and their teammates from 2004 to 2019. In our sample, we examined n = 3198 player statistics. Two groups were created with nominated and not selected players. We used a two-sample t-test, and correlation matrix to examine the relationship between the variables (p < 0.001). We found that scoring is the most important selection criteria for decision-makers (r = 0.605; p = 0.000) and the selected players had significantly better individual statistics. An important finding of our study is that although efficiency (EFF) is used to measure the players’ contribution to the game, it is not the primary selection factor and should therefore be redefined.

In Pursuit of a Comprehensive Understanding of Expertise Development: A Comparison between Paths to World-Class Performance in Complex Technical vs. Endurance Demanding Sports

A comprehensive understanding of skill acquisition is important for different performance domains, and has practical implications for both sport sciences and public health. The study compared important constraints for expertise development in a physically demanding sport (cross-country skiing) versus a technically demanding sport (freeskiing). Eighteen world-class athletes reported the importance of different constraints for their developmental history subdivided into two age spans: (1) 7–15 years and (2) 16 years until present. The total amount of training did not differ between the groups, but from the age of 16, the cross-country skiers spend approximately 98% of their training specific to their main sport, compared to 75% for freeskiers. No differences were found between the distribution of organized versus non-organized training in main sport, but freeskiers reported a higher amount of unorganized training in other sports after the age of 16. No differences were found in perceived importance of facilities, enjoyment of performing their sport, or the need for early specialization of training. After the age of 16, the cross-country skiers reported a higher need for coach involvement compared to freeskiers. The two sports mainly share common paths to expertise but differ in the need for specific training and coach involvement.

Physical Fitness and Performance in Talented & Untalented Young Chinese Soccer Players

Sports performance is a complex process that involves many factors, including ethnic and racial differences. China's youth soccer is in a process of constant development, although information about the characteristics of its players and their methodological systems is scarce. The aim of this retrospective study was to characterize the physical fitness and the competitive performance of 722 Chinese players of three sports categories (8.0-9.9, 10.0-11.9 and 12.0-13.9 years), who were classified by their coaches as talented (n = 204) or untalented (n = 518). Players were assessed for anthropometry (body height, body mass, body mass index), lung capacity (Forced Vital Capacity), jumping performance (Squat Jump, Countermovement Jump and Abalakov tests), sprinting performance (10 m and 30 m Sprint tests), agility performance (Repeated Side-Step test) and flexibility (Sit & Reach test). A descriptive, comparative, correlational and multivariate analysis was performed. Competitive ranking was created in order to act as dependent variable in multiple linear regression analysis. Results indicate that Chinese players classified as talented have better motor performance than untalented ones. However, these differences are neither related nor determine the competitive performance of one group or the other.

Early Specialization and Critical Periods in Acquiring Expertise: A Comparison of Traditional Versus Detection Talent Identification in Team GB Cycling at London 2012

The aim of this study was to compare two methodologies employed by the British Cycling talent identification program. Specifically, the authors investigated cyclists selected to represent GB cycling team at the London 2012 Olympics using (a) a traditional talent identification methodology (British Cycling Olympic Development Program), where selection is based upon race results and (b) a detection talent identification methodology (U.K. Sport Talent Team Program), which is a multi-Olympic event initiative that identifies athletic potential from physical and skill-based tests. To facilitate this comparison, the authors calculated the speed with which expertise was acquired. A Mann–Whitney U test (U = 16.0, p = .031) indicated that the speed of acquiring expertise was quicker in detection talent identification (Mdn = 5.4) than traditional talent identification (Mdn = 7.2). Practice started later with detection talent identification than with traditional talent identification (14.12 years vs. 11.23 years, respectively), which affected the period to excellence. Thus, detection talent identification resulted in an absence of early specialization, which suggests a critical period for attaining cycling expertise. The authors hypothesize a genetic basis of talent and propose that critical periods are important in detection talent identification programs.

Talent Identification in Youth Soccer: Prognosis of U17 Soccer Performance on the Basis of General Athleticism and Talent Promotion Interventions in Second-Grade Children

Several talent identification programs in elementary school have implemented motor diagnostics to introduce children to groups of sports, like game sports, or even to particular sports like soccer. However, as in most other sports, in youth soccer, the predictive value of such early testing is still unclear. This prospective study evaluated the midterm prognostic validity of generic motor performance tests. The sample consisted of male second-grade children, which had received a recommendation to participate in soccer. The talent screening campaign was a basic check comprising two anthropometric parameters, five physical fitness, and three motor competence diagnostics of the German Motor Test 6-18. The test data were collected from the participating elementary school classes of the years 2010 to 2014. The soccer competition performance of those children having completed the age of at least 15 years (n = 502) up to the end of the season 2019/2020 (2020, September 30) was recorded. This group of U17 players was then assigned individually to five different competition levels. The prognostic validity of the physical and physiological tests was determined using ANOVAs, odds ratios, and a regression path analysis. All diagnostic methods exhibited medium-to-high prognostic validity over the 8 year time span from the talent screening to the later soccer competitions in the adolescent age groups. For later success in soccer on the province level, the 6-min run (OR = 4.28), dynamic balance (OR = 4.04), and 20-m sprint (OR = 2.46), as well as the participation in the training center of the German Soccer Federation (OR = 5.67) and the diversity of club sport activities (OR = 3.56), were of particular importance.

The Influence of Contextual Aspects in Talent Development: Interaction Between Relative Age and Birthplace Effects in NBA-Drafted Players

The aims of this study were two-fold: (1) to inspect separately for the relative age and birthplace effects for players selected in the National Basketball Association (NBA) draft; (2) to explore the interaction among these factors and analyse this interaction in players' career performance. The database was obtained from the official records of the players (n = 1,738), who were selected during the annual editions of the NBA Draft from 1990 to 2019. The participants' date of birth was analyzed according to the month of birth and divided into four quartiles. The place of birth was compared to the distribution of the general population' places of birth based on different communities' sizes. Chi-square analysis were used to determine if the relative age and birthplace of the players drafted differed in any systematic way from official census population distributions. Cluster analysis and standardized residuals were calculated to analyse the interaction among the contextual factors and the players' career performance. The data revealed that early-born players (Q1 and Q2) were over-represented. Moreover, players born in smaller cities (<100,000) were over-represented. The interaction analysis revealed that the players born in the bigger communities relate mainly with relatively younger players, and clusters that correspond to players born in smaller communities integrated the relatively older players. No differences were found in the players' career performance. Researchers, coaches and practitioners should be aware of the interaction between contextual factors to help nurture the development of sport talent regardless of age-related issues or communities' size.

The role of growth, maturation and sporting environment on the development of performance and technical and tactical skills in youth basketball players: The INEX study

In this paper, we outline a systematic testing programme developed to help identify excellence in youth basketball players. We examine the links between biological maturation and training experience with anthropometry, body composition, physical performance, technical and tactical skills from five age-cohorts, and characterize, in detail, facets of their environment. In total, 238 young basketball players aged 11-15 years, clustered into five age-cohorts (11, 12, 13, 14, 15 years) were recruited. We assessed measures across three domains: (1) biological [anthropometry, body composition, biological maturation and physical performance]; (2) skill/game proficiency [technical skills and tactical skills]; and (3) contextual [family support, coach knowledge and competence and club context]. The data were analysed using one-way ANOVAs and multivariate analysis of covariance adjusting for biological maturation and training experience. We report significant differences favouring older basketball players on most biological and skill/game proficiency variables. However, differences between age-cohorts in physical performance and technical skills were mitigated after controlling for the effects of both covariates. In conclusion, our findings highlight the important role of both biological maturation and training experience on youth basketball players' performance and development. We discuss the implications of these findings for research as well as for athletes, parents, coaches and clubs.

Swedish Tennis Coaches' Everyday Practices for Creating Athlete Development Environments

Finding and describing the optimal path to elite athletic performance has, for a long time, been a challenge for researchers. This study examined Swedish tennis coaches' everyday practices for creating athlete development environments and the environmental factors that promote or hinder athlete development. The study was conducted in 2018-2019 and included in-depth focus groups with 13 Swedish full-time tennis coaches. Data were analyzed using thematic analysis and by drawing on models for studying athlete development environments. The results highlight how the coaches' everyday work involves a range of administrative tasks, which ultimately means that there is little to no time left for focusing on athlete development. These results also draw attention to concerns about these professional coaches' health, with increasing demands in their roles to manage administrative tasks in addition to the coaching and time spent on the court with their athletes. The results further reveal how the tennis clubs' boards are increasingly interested in sound economy and high participation levels rather than focusing on performance outcomes and developing elite athletes. Finally, the results from this study emphasize the importance of increased collaboration and communication between clubs, coaches, regions, and the national association to create common and clearer guidelines for long-term athlete development. Future studies could engage in longitudinal and ethnographic work with tennis clubs of varying size and geographical locations, involving different stakeholders (e.g., coaches, management, parents, players) in order to further explore the environmental factors that promote or hinder athlete development.

Genetics and the Elite Athlete: Our Understanding in 2020

Modern competitive sport has evolved so much that athletes would go to great extremes to develop themselves into champions; medicine has also evolved to the point that many genetic elements have been identified to be associated with specific athletic traits, and genetic alterations are also possible. The current review examines the published literature and looks at three important factors: genetic polymorphism influencing sporting ability, gene doping and genetic tendency to injury. The ACTN3 gene has an influence on type II muscle fibres, with the R allele being advantageous to power sports like sprinting and the XX genotype being associated with lower muscle strength and sprinting ability. The ACE gene polymorphisms are associated with cardio-respiratory efficiency and could influence endurance athletes. Many other genes are being looked at, with specific focus on those that are potentially related to enhancement of athletic ability. Recognition of these specific gene polymorphisms brings into play the concept of genetic engineering in athletes, which constitutes gene doping and is outlawed. This has the potential to develop into the next big threat in elite sports; gene doping could have dangerous and even fatal outcomes, as the knowledge of gene therapy is still in its infancy. Genetic predisposition to injury is also being identified; recent publications have increased the awareness of gene polymorphisms predisposing to injuries of ligaments and tendons due to influence on collagen structure and extracellular matrix. Ongoing work is looking at identifying the same genes from different races and different sexes to see if there are quantitative racial or sexual differences. All of the above have led to serious ethical concerns; in the twenty-first century some sports associations and some countries are looking at genetic testing for their players. Unfortunately, the science is still developing, and the experience of its application is limited worldwide. Nevertheless, this field has caught the imagination of both the public and the sportsperson, and hence the concerned doctors should be aware of the potential problems and current issues involved in understanding genetic traits and polymorphisms, genetic testing and genetic engineering.

Exploring Forms of Life in Player Development Pathways: The Case of British Rugby League

Social, cultural, and historical constraints can influence attitudes towards learning, developing, and performing in sport. A recent conceptualization of these environmental constraints in athlete development pathways is a form of life, which describes the values, beliefs, traditions, customs, and behaviors that contribute to an athlete’s development. Although a form of life can have a powerful influence on athlete development, research exploring this relationship is limited. In this article we explore the form of life in British rugby league football player development contexts to clarify how social, cultural, and historical constraints influence the development of rugby league players in the United Kingdom. Twenty-four coaches were interviewed through individual semi-structured interviews to collect the data. Findings show how forms of life in rugby league player development pathways are established and maintained by the complex interactions between the microsystem, mesosystem, exosystem, and macrosystem that shape and guide the development of players. We recommend that player development pathways in sport underpin practice with a theoretical framework of the learning process to protect athletes from social, cultural, and historical constraints that are not conducive to their development.

ACE/ACTN3 GENETIC POLYMORPHISMS AND ATHLETIC PERFORMANCE OF FEMALE SOCCER PLAYERS`

ABSTRACT Objective: Previous studies have shown controversial relationships between ACE and ACTN3 gene polymorphisms and sports performance. Thus, the aim of our study was to assess anaerobic and aerobic performance indicators of young female soccer players with different ACE/ACTN3 gene profiles. Methods: Twenty-seven female soccer players aged 16-18 underwent acceleration, speed, strength, anaerobic power and aerobic endurance tests and had their ACE and ACTN3 polymorphisms determined. Results: Based on genetic analysis, they were divided into the following groups: ACE II (n=2), ACE ID (n=11), ACE DD (n=14), ACTN3 XX (n=5), ACTN3 RR (n=7) and ACTN3 RX (n=15). ACE DD and ACE ID groups differed significantly in terms of results achieved on the 5 m sprint test (1.15±0.05 s vs 1.10±0.05 s, P=0.42). ACTN3 RR and RX achieved better results than the ACTN3 XX group in seven continuous vertical jumps (26.57±1.59 cm vs 25.77±2.51 cm vs 22.86±1.16 cm, respectively; P=0.007 for RR vs XX and P=0.021 for RX vs XX). Conclusion: High prevalence of ACE DD and ACTN3 RX genotypes in our subjects may suggest that faster and more powerful young females tend to perform better in soccer. Nevertheless, the absence of differences in most of the physical test results indicates that different genotypes are compatible with high-level soccer performance, meaning that it is the phenotype-genotype interaction that makes a successful female soccer player. Level of Evidence I, Prognostic studies — Investigating the effect of a patient characteristic on disease outcome.

Leistung beschreiben, erklären, vorhersagen und optimieren

Zusammenfassung. Im vorliegenden Artikel wird anlässlich des 50-jährigen Bestehens der asp der Beitrag der Sportpsychologie zum Verständnis von Leistung anhand von vier Leitfragen resümiert, die den Grundanliegen der Psychologie als Wissenschaftsdisziplin folgen: Wie zeigt sich Leistung im Sport und wie lässt sie sich aus psychologischer Perspektive beschreiben? Wie lässt sich das Zustandekommen von Leistung erklären? Was können wir über das Entstehen von Leistung vorhersagen? Wie können wir Leistung optimieren? Im Spannungsfeld von Sport und Leistung steht die menschliche Höchstleistung. Damit einher gehen die Betrachtung der Expertise der Sportlerinnen und Sportler und der Erwerb von Expertise im Sport. Die Talentförderung im Leistungssport wird folglich als inhaltlicher Schwerpunkt gewählt. Sie erlaubt es, die Verbindung zwischen Phänomenen des Leistungssports, Erkenntnisinteresse der Wissenschaft, Erklärungsansätzen, Forschungsergebnissen und Praxistransfer herzustellen. Der Praxistransfer wird anhand eines Überblicks über die praxisbezogenen Beiträge der Zeitschrift für Sportpsychologie und ihrer Vorgänger_innen beleuchtet. Fazit und Ausblick fassen die Ausführungen zusammen und erörtern zukünftige Aufgaben.

Heterogeneity in Community Size Effects: Exploring Variations in the Production of National Hockey League Draftees Between Canadian Cities

Previous research has explored ‘community size effects’ in a multitude of sporting and regional contexts and has shown that athletes are more likely to originate from small-medium population size categories, and less likely to originate from very small or large ones. However, it is not clear whether the production of athletes is homogenous within population size categories. Place of birth data were collected for all Canadian born hockey players drafted into the National Hockey League (NHL) from 2000–2014 from British Columbia (N = 192), Alberta (N = 218), Saskatchewan and Manitoba (N = 216), Ontario (N = 561), Quebec (N = 241), and the Atlantic Provinces (N = 74). To explore variations in the production of draftees within population size categories, proportions of productive cities, population mean (μ), population standard deviation (σ), as well as minimum/maximum values of the number of draftees were calculated for the different categories (<2,500; 2,500–4,999; 5,000–9,999; 10,000–29,999; 30,000–99,999; 100,000–249,999; 250,000–499,999; 500,000–999,999; >1,000,000). In addition, the number of draftees produced per 1,000 residents (i.e., yield) was calculated for each city within all categories. Results showed substantial intra-categorical variability in NHL talent development; moreover, heterogeneity in draftee production existed in various degrees across provincial regions of Canada. Intra-categorical variability suggests that a single homogenous community size effect may not exist for Canadian NHL draftees, and that future research may benefit from exploring other environmental constraints on athlete development such as income, population density, and proximity to local sport clubs.

Multidimensional Monitoring of Recovery Status and Implications for Performance

Monitoring recovery in the context of athletic performance has gained significant importance during recent years. As a systematic process of data collection and evaluation, the monitoring of recovery can be implemented for various purposes. It may help prevent negative outcomes of training or competition, such as underrecovery, overtraining, or injuries. Furthermore, it aims to establish routines and strategies necessary to guarantee athletes' readiness for performance by restoring their depleted resources. Comprehensive monitoring of recovery ideally encompasses a multidimensional approach, thereby considering biological, psychological, and social monitoring methods. From a biological perspective, physiological (eg, cardiac parameters), biochemical (eg, creatine kinase), hormonal (eg, salivary cortisol), and immunological (eg, immunoglobulin A) markers can be taken into account to operationalize training loads and recovery needs. Psychological approaches suggest the application of validated and reliable psychometric questionnaires (eg, Recovery-Stress Questionnaire for Athletes) to measure a subjective perception of recovery, as well as the subjective degree of training- or competition-induced fatigue. Social aspects also play a role in performance monitoring and may hence provide essential performance-related information. The implementation of a monitoring routine in athletic environments represents a continuous process that functions as an effective addition to training and depends on a range of conditions (eg, organizational regulations, commitment of athletes). Current research in the field of monitoring aims to establish individualized monitoring regimens that refer to intraindividual reference values with the help of innovative technological devices.

Parental sport achievement and the development of athlete expertise

This study sought to examine how parental sport involvement and attainment were related to the eventual level of competitive sport attained by their children. Athletes (n = 229) were divided into three skill level groups (elite: n = 139; pre-elite: n = 33; non-elite: n = 57), based on the peak competition level achieved in their career, which were compared using chi-squares tests of independence and analyses of variance according to parents sport characteristics provided through the Developmental History of Athletes Questionnaire. Parental recreational and competitive sport participation was overrepresented among elite athletes, as were parents who reached an elite level of sport themselves. Results were found to differ according to parent sex, with athlete skill level significantly related to the sport participation and skill level of fathers, but not mothers. Results suggest parental sport experiences at different levels of competition influence the development of athletes, although these relationships are subject to many factors.

Talent Identification in Sport: A Systematic Review

BACKGROUND

Talent identification (TID) programs are an integral part of the selection process for elite-level athletes. While many sport organizations utilize TID programs, there does not seem to be a clear set of variables that consistently predict future success.

OBJECTIVE

This review aims to synthesize longitudinal and retrospective studies examining differences between performance variables in highly skilled and less-skilled athletes in elite-level sport.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used to identify relevant studies (N = 20).

RESULTS

There was a clear overrepresentation of studies that (1) examined physical profiles of athletes (60%); (2) focused on male samples (65%); (3) examined athletes between the ages of 10 and 20 years (60%); and (4) were published between the years 2010 and 2015 (65%). On closer examination, there was a high degree of variability in the factors that were found to discriminate between skilled and less-skilled individuals.

CONCLUSION

Findings from this review highlight how little is known about TID in elite sport and emphasize the need for greater diversity in TID research.

Effects of Vitamin D Supplementation on Serum 25-Hydroxyvitamin D Concentrations and Physical Performance in Athletes: A Systematic Review and Meta-analysis of Randomized Controlled Trials

BACKGROUND

There is currently no systematic review examining the effects of vitamin D supplementation among athletes. A rigorous systematic review and meta-analysis is important to provide a balanced view of current knowledge on the effect of vitamin D on serum 25-hydroxyvitamin D [25(OH)D] concentrations and physical performance.

OBJECTIVES

This systematic review of randomized controlled trials (RCTs) evaluated the effects of oral vitamin D supplementation on serum 25(OH)D concentrations and physical performance in athletes.

METHODS

Multiple electronic databases were searched, and study eligibility, methodological quality assessment, and data extraction were completed independently and in duplicate. Studies were stratified by baseline vitamin D sufficiency, season, and latitude. A cut-off of 30 ng/ml (75 nmol/l) of 25(OH)D was used for sufficiency. Absolute mean differences (AMDs) between vitamin D and placebo using random effects analysis, and heterogeneity using Q statistic and I ² index, were calculated. AMD with 95% confidence interval (CI), p value, and I ² are reported.

RESULTS

In total, 13 RCTs (2005-2016) with 532 athletes (vitamin D 311, placebo 221) were eligible. A total of 433 athletes (vitamin D 244, placebo 189) had complete outcome data. Among athletes with baseline values suggesting insufficiency, vitamin D supplementation led to significant increases from 3000 IU (AMD 15.2 ng/ml; 95% CI 10.7-19.7, p < 0.0001, I ² = 0%) and 5000 IU (AMD 27.8 ng/ml; 95% CI 16.9-38.8, p < 0.0001, I ² = 78%) per day at >45° latitudes. Both doses led to sufficiency concentrations during winter months. Among athletes with baseline vitamin D suggesting sufficiency, serum 25(OH)D sufficiency was maintained from different doses at both latitudes. Of 13 included trials, only seven measured different physical performances and none demonstrated a significant effect of vitamin D supplementation during 12 weeks of follow-up.

CONCLUSION

Despite achieving sufficiency in vitamin D concentrations from ≥3000 IU supplementation, physical performance did not significantly improve. Between-study heterogeneity was large, and well-designed RCTs examining the effect of vitamin D supplementation on serum 25(OH)D concentrations, physical performance, and injuries in different sports, latitudes, ethnicities, and vitamin D status are needed.

A Medal in the Olympics Runs in the Family: A Cohort Study of Performance Heritability in the Games History

Introduction: Elite performance in sports is known to be influenced by heritable components, but the magnitude of such an influence has never been quantified.

Hypothesis/Objectives: We hypothesized that having a former world-class champion in the family increases the chances of an athlete to repeat the achievement of her or his kinship. We aimed to measure the heritability of a medal in the Olympic Games (OG) among Olympians and to estimate the percentage of the genetic contribution to such a heritance.

Study Design: Twin-family study of a retrospective cohort.

Methods: All the 125,051 worldwide athletes that have participated in the OG between 1896 and 2012 were included. The expected probability to win a medal in the OG was defined as the frequency of medallists among Olympians without any blood kinship in the OG. This expected probability was compared with the probability to win a medal for Olympians having a kinship (grandparent, aunt/uncle, parent, or siblings) with a former Olympian that was a (1) non-medallist or (2) medallist. The heritability of the genetically determined phenotype (h²) was assessed by probandwise concordance rates among dizygotic (DZ) and monozygotic (MZ) twins (n = 90).

Results: The expected probability to win a medal in the OG was 20.4%. No significant difference of medal probability was found in the subgroups of Olympians with a Non-medallist kinship, except among siblings for whom this probability was lower: 13.3% (95% CI 11.2–14.8). The medal probability was significantly greater among Olympians having a kinship with a former Olympic Medallist: 44.4% for niece/nephew (33.7–54.2); 43.4% for offspring (37.4–48.6); 64.8% for siblings (61.2–68.8); 75.5% for DZ twins (63.3–86.6); and 85.7% for MZ twins (63.6–96.9); with significantly greater concordance between MZ than DZ (p = 0.01) and h² estimated at 20.5%.

Conclusion: Having a kinship with a former Olympic medallist is associated with a greater probability for an Olympian to also become a medallist, the closer an athlete is genetically to such kinship the greater this probability. Once in the OG, the genetic contribution to win a medal is estimated to be 20.5%.

Population density and proximity to junior developmental teams affect the development of National Hockey League draftees

Inconsistencies in community size effects found between and within countries (Baker et al Eur J Sport Sci. 2009;9:329-339; Bruner et al J Sports Sci. 2011;29:1337-1344; Wattie et al J Sports Sci. 2018;36:436-444) suggest population size may not be an accurate predictor of athlete development and that other proxies of early environmental characteristics are needed. Researchers have begun to explore the influence of population density and proximity to local sport clubs on athlete development in European countries; however, similar analysis remains to be conducted in Canadian ice hockey. The current study focused on National Hockey League (NHL) draftees and explored whether population density and proximity to Canadian Hockey League teams were associated with the number of draftees produced. Linear regression analyses showed a significant positive relationship between population density and the development of draftees in all provincial regions; however, a significant negative relationship between proximity to CHL teams and NHL draftee development was observed in four out of six provincial regions (British Columbia, Ontario, Quebec, and the Atlantic Provinces). Moreover, population density appeared to be a better predictor of NHL talent development than proximity to CHL teams. Future research may benefit from exploring the effects of these two variables within population size categories, as well as between different regions within provinces.

Marathon Specialization in Elites: A Head Start for Africans

PURPOSE

To assess differences in event-specific specialization between elite African and non-African male marathon runners based on age, performance, and career length.

METHODS

The top 90 African marathoners from 2001 to 2015 were compared with the top 90 non-African marathoners from the same time period across various markers related to specialization age, performance, and career length. Independent t tests were used to identify significant differences (P < .05) between the African and non-African groups. Linear regression was used to explore the relationship between first half-marathon and best full-marathon performance. A 1-way ANOVA and Bonferroni correction was used to assess differences in specialization age and rates of performance improvement and decline.

RESULTS

African marathoners were found to specialize, reach peak levels of performance, and retire at younger ages than non-African marathoners (P < .001). In addition, African marathoners were found to be faster at these same career time points and in half-marathon performance (P < .001). There was no significant difference in the number of career marathons run between groups, but African marathoners were found to race more frequently than non-African marathoners (P < .001). Half-marathon performance was positively correlated with marathon performance (r² = .67). Marathon athletes who specialized at early ages experienced significantly higher rates of improvement than those who specialized at older ages. (P < .05).

CONCLUSIONS

The findings suggest that elite African marathoners achieve a greater level of performance at younger ages than their non-African counterparts. Furthermore, current marathon talent-identification practice may benefit from using half-marathon performance.

Understanding Personalized Training Responses: Can Genetic Assessment Help?

Background:

Traditional exercise prescription is based on the assumption that exercise adaptation is predictable and standardised across individuals. However, evidence has emerged in the past two decades demonstrating that large inter-individual variation exists regarding the magnitude and direction of adaption following exercise.

Objective:

The aim of this paper was to discuss the key factors influencing this personalized response to exercise in a narrative review format.

Findings:

Genetic variation contributes significantly to the personalized training response, with specific polymorphisms associated with differences in exercise adaptation. These polymorphisms exist in a number of pathways controlling exercise adaptation. Environmental factors such as nutrition, psycho-emotional response, individual history and training programme design also modify the inter-individual adaptation following training. Within the emerging field of epigenetics, DNA methylation, histone modifications and non-coding RNA allow environmental and lifestyle factors to impact genetic expression. These epigenetic mechanisms are themselves modified by genetic and non-genetic factors, illustrating the complex interplay between variables in determining the adaptive response. Given that genetic factors are such a fundamental modulator of the inter-individual response to exercise, genetic testing may provide a useful and affordable addition to those looking to maximise exercise adaption, including elite athletes. However, there are ethical issues regarding the use of genetic tests, and further work is needed to provide evidence based guidelines for their use.

Conclusion:

There is considerable inter-individual variation in the adaptive response to exercise. Genetic assessments may provide an additional layer of information allowing personalization of training programmes to an individual’s unique biology.

Sport expertise in perception-action coupling revealed in a visuomotor tracking task

We compared the visuomotor coordination of tennis players with different levels of expertise (Super-Experts, Experts and Non-Experts) in a visuomotor tracking (VMT) task. Participants were asked to track a moving target which could rebound on the sides of a 2D screen. Results indicated that the VMT task allowed the discrimination of expertise. Multiple regression analysis revealed that performance could be explained by the temporal adaptation of participants to rebounds and the number of movement adaptations. Compared to Non-Experts, the Experts had a shorter perturbation time with higher adaptation and regulation. This corresponds to a better perception-action coupling and the predominant use of a prospective control process. Results also indicate that perception-action coupling capacities are transferable to virtual tasks, and allow us to reveal processes of visuomotor coordination that differentiate experts and novices.

A Dynamic Network Model to Explain the Development of Excellent Human Performance

Across different domains, from sports to science, some individuals accomplish excellent levels of performance. For over 150 years, researchers have debated the roles of specific nature and nurture components to develop excellence. In this article, we argue that the key to excellence does not reside in specific underlying components, but rather in the ongoing interactions among the components. We propose that excellence emerges out of dynamic networks consisting of idiosyncratic mixtures of interacting components such as genetic endowment, motivation, practice, and coaching. Using computer simulations we demonstrate that the dynamic network model accurately predicts typical properties of excellence reported in the literature, such as the idiosyncratic developmental trajectories leading to excellence and the highly skewed distributions of productivity present in virtually any achievement domain. Based on this novel theoretical perspective on excellent human performance, this article concludes by suggesting policy implications and directions for future research.

Anthropometric characteristics, physical fitness and motor coordination of 9 to 11 year old children participating in a wide range of sports

Objectives

The aim of this study was to investigate to what extent 9 to 11 year old children participating in a specific sport already exhibit a specific anthropometric, physical fitness and motor coordination profile, in line with the requirements of that particular sport. In addition, the profiles in children with a different training volume were compared and possible differences in training hours per week between children from a low, moderate, and high level of physical fitness and motor coordination were investigated.

Methods and Results

Data of 620 children, 347 boys and 273 girls, who participated in the Flemish Sports Compass were used. Only the primary sport of each child was considered and six groups of sports (Ball sports, Dance, Gymnastics, Martial arts, Racquet sports and Swimming) were formed based on common characteristics. Measurements consisted of 17 tests. Independent T-tests and Mann-Whitney U-tests revealed few differences between the groups of sports and the discriminant analyses with the moderate and low active group did not show any significant results (p > .05). However, when discriminating among the high active children, a 85.2 % correct classification between six groups of sports was found (Wilks’ Λ = .137 and p < .001). Finally, children performing under average on the tests spent significantly fewer hours in sport per week (2.50 ± 1.84 hours) compared to the children performing best (3.25 ± 2.60 hours) (p = .016) and the children performing above average (2.90 ± 1.96 hours) (p = .029) on physical fitness and motor coordination.

Discussion

The study showed that in general, children at a young age do not exhibit sport-specific characteristics, except in children with a high training volume. It is possible that on the one hand, children have not spent enough time yet in their sport to develop sport-specific qualities. On the other hand, it could be possible that they do not take individual qualities into account when choosing a sport.

New frontiers in sport training: genetics and artistic gymnastics

The increasing understanding of the genetic influences in sport has prompted an association study between the athletic performances and the polymorphisms of the angiotensin-converting enzyme (ACE), the α-actinin-3 (ACTN3), and the vitamin D receptor genes. The details of these gene polymorphisms can provide useful information to improve and plan new modern training programs for elite athletes. Eighty Italian male high level gymnasts were trained and tested for gymnastic-specific exercises and tested in all the men's artistic gymnastic apparatus (floor, pommel horse, rings, vault, parallel bars, and horizontal bar), and then genotyped. The training parameters of volume, intensity, and density of each gymnast were periodically measured during the season in each apparatus from the tests performed, and the seasonal average values were calculated. Gene polymorphisms were determined by polymerase chain reaction restriction fragment length polymorphism assay and studied in association with the performance results. The performances of ACE II gymnasts were significantly lower than that of the ACE ID/DD gymnasts in the apparatus expressing power features, confirming the predisposition of these athletes toward power-oriented sport. Gymnasts with ACTN3 RR/RX genotypes did not show a predisposition to the power-oriented apparatus, having worse performances compared with that of the ACTN3 XX gymnasts. Similarly, gymnasts with ACE II + ACTN3 RR/RX combined genotypes showed lower performances in comparison with that of the other gymnasts. Vitamin D receptor polymorphisms showed no significant association with the athletic performances. Because ACE insertion/deletion (I/D) and ACTN3 R577X polymorphisms heavily affect the physical performance of elite male gymnasts, the Italian Gymnastic Federation trainers have started to customize the current high-level training programs.

Lack of Association Between ACE Indel Polymorphism and Cardiorespiratory Fitness in Physically Active and Sedentary Young Women

Background:

Polymorphisms at the angiotensin-converting enzyme gene (ACE), such as the indel [rs1799752] variant in intron 16, have been shown to be associated with aerobic performance of athletes and non-athletes. However, the relationship between ACE indel polymorphism and cardiorespiratory fitness has not been always demonstrated.

Objectives:

The relationship between ACE indel polymorphism and cardiorespiratory fitness was investigated in a sample of young Caucasian Brazilian women.

Patients and Methods:

This study investigated 117 healthy women (aged 18 to 30 years) who were grouped as physically active (n = 59) or sedentary (n = 58). All subjects performed an incremental exercise test (ramp protocol) on a cycle-ergometer with 20-25 W/min increments. Blood samples were obtained for DNA extraction and to analyze metabolic and hormonal profiles. ACE indel polymorphism was determined by polymerase chain reaction (PCR) and fragment size analysis.

Results:

The physically active group had higher values of peak oxygen uptake (VO₂ peak), carbon dioxide output (VCO₂), ventilation (VE) and power output than the sedentary group (P < 0.05) at the peak of the exercise test. However, heart rate (HR), systolic blood pressure (SBP) and diastolic blood pressure (DBP) did not differ between groups. There was no relationship between ACE indel polymorphism and cardiorespiratory variables during the test in both the physically active and sedentary groups, even when the dominant (DD vs. D1 + 2) and recessive (2 vs. DI + DD) models of inheritance were tested.

Conclusions:

These results do not support the concept that the genetic variation at the ACE locus contributes to the cardiorespiratory responses at the peak of exercise test in physically active or sedentary healthy women. This indicates that other factors might mediate these responses, including the physical training level of the women.

Level of competitive success achieved by elite athletes and multi-joint proprioceptive ability

OBJECTIVES

Proprioceptive ability has been suggested to underpin elite sports performance. Accordingly, this study examined the relationship between an athlete's proprioceptive ability, competition level achieved, and years of sport-specific training.

DESIGN

Cross-sectional study.

METHODS

One hundred elite athletes, at competition levels ranging from regional to international, in aerobic gymnastics, swimming, sports dancing, badminton and soccer, were assessed for proprioceptive acuity at the ankle, knee, spine, shoulder, and finger joints. An active movement extent discrimination test was conducted at each joint, to measure ability to discriminate small differences in movements made to physical stops.

RESULTS

Multiple regression analysis showed that 30% of the variance in the sport competition level an athlete achieved could be accounted for by an equation that included: ankle movement discrimination score, years of sport-specific training, and shoulder and spinal movement discrimination scores (p<0.001). Mean proprioceptive acuity score over these three predictor joints was significantly correlated with sport competition level achieved (r=0.48, p<0.001), highlighting the importance of proprioceptive ability in underpinning elite sports performance. Years of sport-specific training correlated with an athlete's sport competition level achieved (r=0.29, p=0.004), however, proprioceptive acuity was not correlated with years of sport-specific training, whether averaged over joints or considered singly for each joint tested (all r≤0.13, p≥0.217).

CONCLUSIONS

Proprioceptive acuity is significantly associated with the performance level achieved by sports elites. The amount of improvement in proprioceptive acuity associated with sport-specific training may be constrained by biologically determined factors.

Genetic influence on athletic performance

PURPOSE OF REVIEW

To summarize the existing literature on the genetics of athletic performance, with particular consideration for the relevance to young athletes.

RECENT FINDINGS

Two gene variants, ACE I/D and ACTN3 R577X, have been consistently associated with endurance (ACE I/I) and power-related (ACTN3 R/R) performance, though neither can be considered predictive. The role of genetic variation in injury risk and outcomes is more sparsely studied, but genetic testing for injury susceptibility could be beneficial in protecting young athletes from serious injury. Little information on the association of genetic variation with athletic performance in young athletes is available; however, genetic testing is becoming more popular as a means of talent identification. Despite this increase in the use of such testing, evidence is lacking for the usefulness of genetic testing over traditional talent selection techniques in predicting athletic ability, and careful consideration should be given to the ethical issues surrounding such testing in children.

SUMMARY

A favorable genetic profile, when combined with an optimal training environment, is important for elite athletic performance; however, few genes are consistently associated with elite athletic performance, and none are linked strongly enough to warrant their use in predicting athletic success.

Analysis of the relationship between the amount of training and cognitive expertise. A study of young volleyball players

The main goal of this research was to analyze the relationship between the amount of practice accumulated in training and the level of cognitive expertise achieved by volleyball players who are still in training. Another goal was to determine the number of training hours per week needed to improve knowledge significantly. The study's sample was composed of 520 volleyball players between the ages of 12 and 16 years. The independent variable was the amount of training, defined as the number of weekly hours that the volleyball player devoted to training. The dependent variable was cognitive expertise, measured by declarative knowledge and procedural knowledge. A univariate analysis of variance was done to examine the relationship between the number of weekly hours and the declarative and procedural knowledge reached by volleyball players in the athletic formation training stages. Statistical significance was set at p < 0.05. There were significant differences in knowledge according to the number of weekly training hours (p < 0.001). These results confirm that there is a relationship between the quantity of practice and the development of cognitive expertise. It is recommended that young players dedicate at least 4 hours weekly to training to achieve a significant improvement in cognitive expertise.

Epigenetics in sports

The heritability of specific phenotypical traits relevant for physical performance has been extensively investigated and discussed by experts from various research fields. By deciphering the complete human DNA sequence, the human genome project has provided impressive insights into the genomic landscape. The hope that this information would reveal the origin of phenotypical traits relevant for physical performance or disease risks has proven overly optimistic, and it is still premature to refer to a 'post-genomic' era of biological science. Linking genomic regions with functions, phenotypical traits and variation in disease risk is now a major experimental bottleneck. The recent deluge of genome-wide association studies (GWAS) generates extensive lists of sequence variants and genes potentially linked to phenotypical traits, but functional insight is at best sparse. The focus of this review is on the complex mechanisms that modulate gene expression. A large fraction of these mechanisms is integrated into the field of epigenetics, mainly DNA methylation and histone modifications, which lead to persistent effects on the availability of DNA for transcription. With the exceptions of genomic imprinting and very rare cases of epigenetic inheritance, epigenetic modifications are not inherited transgenerationally. Along with their susceptibility to external influences, epigenetic patterns are highly specific to the individual and may represent pivotal control centers predisposing towards higher or lower physical performance capacities. In that context, we specifically review how epigenetics combined with classical genetics could broaden our knowledge of genotype-phenotype interactions. We discuss some of the shortcomings of GWAS and explain how epigenetic influences can mask the outcome of quantitative genetic studies. We consider epigenetic influences, such as genomic imprinting and epigenetic inheritance, as well as the life-long variability of epigenetic modification patterns and their potential impact on phenotype with special emphasis on traits related to physical performance. We suggest that epigenetic effects may also play a considerable role in the determination of athletic potential and these effects will need to be studied using more sophisticated quantitative genetic models. In the future, epigenetic status and its potential influence on athletic performance will have to be considered, explored and validated using well controlled model systems before we can begin to extrapolate new findings to complex and heterogeneous human populations. A combination of the fields of genomics, epigenomics and transcriptomics along with improved bioinformatics tools and precise phenotyping, as well as a precise classification of the test populations is required for future research to better understand the inter-relations of exercise physiology, performance traits and also susceptibility towards diseases. Only this combined input can provide the overall outlook necessary to decode the molecular foundation of physical performance.

Acquisition of expertise in cricket fast bowling: perceptions of expert players and coaches

OBJECTIVES

Experiential knowledge of elite athletes and coaches was investigated to reveal insights on expertise acquisition in cricket fast bowling.

DESIGN

Twenty-one past or present elite cricket fast bowlers and coaches of national or international level were interviewed using an in-depth, open-ended, semi-structured approach.

METHODS

Participants were asked about specific factors which they believed were markers of fast bowling expertise potential. Of specific interest was the relative importance of each potential component of fast bowling expertise and how components interacted or developed over time.

RESULTS

The importance of intrinsic motivation early in development was highlighted, along with physical, psychological and technical attributes. Results supported a multiplicative and interactive complex systems model of talent development in fast bowling, in which component weightings were varied due to individual differences in potential experts. Dropout rates in potential experts were attributed to misconceived current talent identification programmes and coaching practices, early maturation and physical attributes, injuries and lack of key psychological attributes and skills.

CONCLUSIONS

Data are consistent with a dynamical systems model of expertise acquisition in fast bowling, with numerous trajectories available for talent development. Further work is needed to relate experiential and theoretical knowledge on expertise in other sports.

Genomics of elite sporting performance: what little we know and necessary advances

Numerous reports of genetic associations with performance- and injury-related phenotypes have been published over the past three decades; these studies have employed primarily the candidate gene approach to identify genes that associate with elite performance or with variation in performance-and/or injury-related traits. Although generally with small effect sizes and heavily prone to type I statistic error, the number of candidate genetic variants that can potentially explain elite athletic status, injury predisposition, or indeed response to training will be much higher than that examined by numerous biotechnology companies. Priority should therefore be given to applying whole genome technology to sufficiently large study cohorts of world-class athletes with adequately measured phenotypes where it is possible to increase statistical power. Some of the elite athlete cohorts described in the literature might suffice, and collectively, these cohorts could be used for replication purposes. Genome-wide association studies are ongoing in some of these cohorts (i.e., Genathlete, Russian, Spanish, Japanese, United States, and Jamaican cohorts), and preliminary findings include the identification of one single nucleotide polymorphism (SNP; among more than a million SNPs analyzed) that associates with sprint performance in Japanese, American (i.e., African American), and Jamaican cohorts with a combined effect size of ~2.6 (P-value <5×10(-7)) and good concordance with endurance performance between select cohorts. Further replications of these signals in independent cohorts will be required, and any replicated SNPs will be taken forward for fine-mapping/targeted resequencing and functional studies to uncover the underlying biological mechanisms. Only after this lengthy and costly process will the true potential of genetic testing in sport be determined.

The influence of birth date and place of development on youth sport participation

Previous research highlights the critical role that contextual factors play in shaping athlete development. The purpose of the present study was to investigate two of these contextual factors: birth date (known as the relative age effect, RAE) and city of development as determinants of participation in a sample of youth ice hockey players. The sample included 146,424 athletes registered with Ontario youth ice hockey between the 2004 and 2010 seasons. Chi-square statistics determined a significant RAE in youth ice hockey. Findings also revealed a significant association between small cities of development and increased youth ice hockey participation. Finally, there was no evidence of an interaction between relative age and city of development. The characteristics of smaller communities that may facilitate sport participation across all youth are discussed, along with recommendations for future research.

The developmental activities of elite soccer players aged under-16 years from Brazil, England, France, Ghana, Mexico, Portugal and Sweden

The developmental activities of 328 elite soccer players aged under-16 years from Brazil, England, France, Ghana, Mexico, Portugal and Sweden were examined using retrospective recall in a cross-sectional research design. The activities were compared to the early diversification, early specialisation, and early engagement pathways. Players started their involvement in soccer at approximately 5 years of age. During childhood, they engaged in soccer practice for a mean value of 185.7, s = 124.0 h · year(-¹), in soccer play for 186.0, s = 125.3 h · year(-¹), and in soccer competition for 37.1, s = 28.9 h · year(-¹). A mean value of 2.3, s = 1.6 sports additional to soccer were engaged in by 229 players during childhood. Players started their participation in an elite training academy at 11 to 12 years of age. During adolescence, they engaged in soccer practice for a mean value of 411.9, s = 184.3 h · year(-¹), in soccer play for 159.7, s = 195.0 h · year(-¹), and in soccer competition for 66.9, s = 48.8 h · year(-¹). A mean value of 2.5, s = 1.8 sports other than soccer were engaged in by 132 players during this period. There were some relatively minor differences between countries, but generally the developmental activities of the players followed a mixture of the early engagement and specialisation pathways, rather than early diversification.

Similar slow down in running speed progression in species under human pressure

Running speed in animals depends on both genetic and environmental conditions. Maximal speeds were here analysed in horses, dogs and humans using data sets on the 10 best performers covering more than a century of races. This includes a variety of distances in humans (200-1500 m). Speed has been progressing fast in the three species, and this has been followed by a plateau. Based on a Gompertz model, the current best performances reach 97.4% of maximal velocity in greyhounds to 100.3 in humans. Further analysis based on a subset of individuals and using an 'animal model' shows that running speed is heritable in horses (h(2) = 0.438, P = 0.01) and almost so in dogs (h(2) = 0.183, P = 0.08), suggesting the involvement of genetic factors. Speed progression in humans is more likely due to an enlarged population of runners, associated with improved training practices. The analysis of a data subset (40 last years in 800 and 1500 m) further showed that East Africans have strikingly improved their speed, now reaching the upper part of the human distribution, whereas that of Nordic runners stagnated in the 800 m and even declined in the 1500 m. Although speed progression in dogs and horses on one side and humans on the other has not been affected by the same genetic/environmental balance of forces, it is likely that further progress will be extremely limited.

The COL5A1 Gene, Ultra-Marathon Running Performance, and Range of Motion

Purpose:

Endurance running performance is a multifactorial phenotype that is strongly associated with running economy. Sit and reach range of motion (SR ROM) is negatively associated with running economy, suggesting that reduced SR ROM is advantageous for endurance running performance. The COL5A1 gene has been associated with both endurance running performance and SR ROM in separate cohorts. The aim of this study was to investigate whether COL5A1 is associated with ultra-marathon running performance and whether this relationship could be partly explained by prerace SR ROM.

Methods:

Seventy-two runners (52 male, 20 female) were recruited from the 56 km Two Oceans ultra-marathon and were assessed for prerace SR ROM. The cohort was genotyped for the COL5A1 BsfUI restriction fragment length polymorphism, and race times were collected after the event.

Results:

Participants with a TT genotype (341 ± 41 min, N = 21) completed the 56 km Two Oceans ultra-marathon significantly (P = 0.014) faster than participants with TC and CC genotypes (365 ± 39 min, N = 50). The COL5A1 genotype and age accounted for 19% of performance variance. When the cohort was divided into performance and flexibility quadrants, the T allele was significantly (P = 0.044) over-represented within the fast and inflexible quadrant.

Conclusion:

The COL5A1 genotype was found to be significantly associated with performance in a 56 km ultra-endurance run. This study confirms previous findings and it furthers our understanding of the relationships among ROM, COL5A1, and endurance running performance. We continue to speculate that the COL5A1 gene alters muscle-tendon stiffness.

When to initiate integrative neuromuscular training to reduce sports-related injuries and enhance health in youth?

Regular participation in organized youth sports does not ensure adequate exposure to skill- and health-related fitness activities, and sport training without preparatory conditioning does not appear to reduce risk of injury in young athletes. Current trends indicate that widespread participation in organized youth sports is occurring at a younger age, especially in girls. Current public health recommendations developed to promote muscle strengthening and bone building activities for youth aged 6 yr and older, along with increased involvement in competitive sport activities at younger ages, has increased interest and concern from parents, clinicians, coaches, and teachers regarding the optimal age to encourage and integrate more specialized physical training into youth development programs. This review synthesizes the latest literature and expert opinion regarding when to initiate neuromuscular conditioning in youth and presents a how-to integrative training conceptual model that could maximize the potential health-related benefits for children by reducing sports-related injury risk and encouraging lifelong, regular physical activity.

Early Sport Involvement in Young Portuguese Basketball Players

The purpose of this study was to examine the quantity and type of sporting activities undertaken by young Portuguese basketball players in early stages of athletic development. 750 basketball players aged between 12 and 16 years served as participants, grouped by sex and competitive level. The Skilled group comprised players representing the 9 highly ranked regional teams ( n = 378) while the Less-skilled group comprised the players representing the remaining 9 regional teams ( n = 372). All the participants filled out a previously validated questionnaire based on retrospective information linked to the training activities experienced throughout their involvement in sport. Results suggest that the majority of the players started practicing sports preferentially between 6 and 10 years. However, a significant number of players reported a later start, between 11 and 14 years of age. The pattern of sport involvement confirmed important divergences in the path reported by the players by the team's competitive level. The major findings of this study confirmed that players representing the highly ranked teams demonstrated a tendency to extend their training activities during longer periods during the week and throughout each season.