bio-banding in sport: applications to competition, talent ...96%of adult height, peaking...

Bio-banding in Sport:Applications toCompetition, TalentIdentification, andStrength andConditioning of YouthAthletesSean P. Cumming, PhD,1 Rhodri S. Lloyd, PhD,2,3 Jon L. Oliver, PhD,2,3 Joey C. Eisenmann, PhD,4

and Robert M. Malina, PhD5,6

1Department for Health, University of Bath, Bath, United Kingdom; 2Youth Physical Development Centre, CardiffMetropolitan University, Cardiff, United Kingdom; 3Sports Performance Research Institute New Zealand, AucklandUniversity of Technology, Auckland, New Zealand; 4College of Osteopathic Medicine, Michigan State University, EastLansing, Michigan; 5Department of Kinesiology and Health Education, University of Texas, Austin, Texas; and 6TarletonState University, Stephenville, Texas

A B S T R A C T

BIO-BANDING IS THE PROCESSOF

GROUPING ATHLETES ON THE

BASIS OF ATTRIBUTES ASSOCI-

ATED WITH GROWTH AND MATU-

RATION RATHER THAN

CHRONOLOGICAL AGE. CHIL-

DREN OF THE SAME AGE VARY

CONSIDERABLY IN BIOLOGICAL

MATURATION WITH SOME INDI-

VIDUALS MATURING IN ADVANCE

OR DELAY OF THEIR PEERS. THE

TIMING OF MATURATION HAS

IMPORTANT IMPLICATIONS FOR

COMPETITION, TALENT IDENTIFI-

CATION, AND TRAINING.

INCREASED AWARENESS AND

INTEREST IN THE SUBJECT OF

MATURATION HAS SPARKED A

RENEWED INTEREST IN THE

STUDY AND APPLICATION OF BIO-

BANDING. THIS OVERVIEW DE-

SCRIBES THE PURPOSE AND

PROCESS OF BIO-BANDING,

POTENTIAL BENEFITS AND LIMITA-

TIONS, AND DESCRIBES SOME

RECENT ADVANCES IN ITS APPLI-

CATION IN YOUTH SPORTS.

INTRODUCTION

Young athletes are traditionallygrouped by chronological age(i.e., age based on the calendar

date on which an individual was born)for the purpose of competition andtraining. Children of the same chrono-logical age may, however, vary in bio-logical maturity with some individualsmaturing in advance or delay relative

to their peers. Maturation refers toprogress toward the adult or maturestate and can be defined in terms ofstatus, timing, and tempo (54,56,61).Whereas status refers to the state ofmaturation at the time of observation(e.g., prepubertal, pubertal, postpuber-tal), timing refers to the age at whichspecific maturational events occur,such as age at menarche and age at peakheight velocity (PHV). Tempo refers tothe rate at which maturation progresses.Children of the same age can vary inrate, with some individuals reachingadulthood in advance of others.

Individual differences in the timing ofmaturation impact both physical and

Address correspondence to Sean P. Cumming,[email protected].

KEY WORDS :

adolescence maturation; puberty; sport;youth

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Copyright ª National Strength and Conditioning Association. Unauthorized reproduction of this article is prohibited.

psychosocial development (6,56,77).Boys who mature in advance of theirpeers are, on average, taller and heavierfrom late childhood. Early maturingboys also tend to experience a moreintense adolescent growth spurt (i.e.,greater PHV), resulting in greaterpubertal gains in height, weight, andlean mass (56). This affords the earlymaturing male potential athletic advan-tages, i.e., greater size, strength, speed,and power, especially between the agesof 11 and 14 years when maturity-associated differences in size and func-tion are at their greatest (61). Heightdifferences among early, average (ontime), and late maturing youth are,however, negligible in late adoles-cence/early adulthood. From a psycho-logical perspective, early maturingboys present a more adaptive motiva-tional profile with higher perceptionsof the physical self, i.e., strength, attrac-tiveness, physical fitness, and sportcompetence, and greater self-esteem(24,48). Consequently, early maturingboys are more likely to be attractedtoward, and selected into, sports wheregreater size, strength, and power aredesirable attributes, for example, icehockey, American football, soccer,rugby, basketball, and swimming (61).

The physical and psychological conse-quences of maturity timing in femalesare not directly equivalent to thoseobserved in males. Like boys, girlswho mature in advance of their peersare taller, heavier, and experiencea more intense pubertal growth spurt(56). Pubertal gains in mass in femalesare, however, largely attributable tobody fat, with comparatively smallergains in lean mass relative to males.As a consequence, early maturing girlstend to outperform their later maturingpeers on tests of absolute strength,whereas differences in performancesof girls of contrasting maturity statusin tests of speed, agility, and powerare negligible (9,56). Early maturing fe-males are often overrepresented insports that emphasize size or strength,such as tennis and swimming, andunderrepresented in sports thatemphasize aesthetic qualities and/or

relative strength and endurance, suchas gymnastics, diving, distance running,figure skating, and cycling. Girlsadvanced in maturation also presenta less adaptive psychological profilewith lower levels of self-esteem (68)and more negative perceptions ofphysical attractiveness, fitness, andsport competence (25,38). The associ-ations may, however, vary with culturaland societal expectations and idealspertaining to female attractiveness (24).

Individual differences in growth andmaturation may contribute to compet-itive inequity and increased risk ofinjury, especially for athletes who areconstitutionally small and/or delayedin maturation (44,52). In this context,proposals to match athletes on thebasis of physical attributes rather thanchronological age have a long tradition(5,30,55). This strategy is currentlylabeled “bio-banding” and involvesthe grouping and/or evaluating ath-letes on the basis of size and/or matu-rity status rather than chronologicalage. Although bio-banding places ath-letes into groups on the basis of phys-ical characteristics, it does not precludethe consideration of psychologicaland/or technical skills. An early matur-ing boy, for example, might be discour-aged from competing against ortraining with older youth if they lackedthe technical competence and/or psy-chological maturity to ensure a safeand positive experience (50,51). Simi-larly, a late maturing boy who isalready thriving within his age groupis unlikely to benefit from competingagainst peers who are younger but ofsimilar maturity. Bio-banding does notpreclude the consideration of technicaland psychological development. Theseattributes should be taken into consid-eration when grouping athletes by sizeand/or maturation for the purpose oftraining and competition.

BIO-BANDING: A HISTORY OF THECONCEPT

The concept of grouping children onthe basis of physical rather than chrono-logical age was first advocated in theearly 20th century. With reference tochild labor, Crampton (21) proposed

the use of “physiological age,” basedon the development of pubic hair (PH;i.e., a secondary sex characteristic), asa more suitable determinant of readinessto work. A year later, Rotch (75) pro-posed the use of “anatomic age,” basedon the radiographic assessment of thecarpal bones, for grouping children inboth school and sports. Commentingon the overrepresentation of earlymaturing boys competing in the 1957Baseball Little League World Series,Krogman (45) suggested that assess-ments of maturation should be consid-ered when determining player eligibilityand evaluating athletic potential.

The process of grouping young athleteson the basis of age and weight-basedcriteria is common in combat sports(e.g., boxing, judo, taekwondo, andwrestling), in which extreme size mis-matches are considered to have impli-cations for competitive equity andathlete safety (2). Similar size-basedgrouping strategies have been imple-mented in collision sports, such as rugbyand American football at younger ages,although they tend to be the exceptionrather than the rule. Concerns regardingthe larger size of some children, partic-ularly those of Polynesian and Maoridescent, have prompted a number ofyouth rugby programs in New Zealandto use weight-based criteria to groupchildren within age groups and/ormove players between age groups(86). Weight restricted divisions inrugby are limited to children of a specificage at or below a specific weight crite-rion (e.g., under 11s # 43 kg). For sim-ilar reasons, some junior Americanfootball programs have used weight cri-teria to permit children to play down anage band and designate which individ-uals are allowed to play specific posi-tions and/or advance the ball (86).Adopting a similar, yet more holisticapproach, the New York State PublicHigh School Association employ anathlete dispensation rule whereby sev-enth and eighth graders wishing to par-ticipate in interscholastic high schoolssports are assessed on a combination ofphysical, psychological, and technicalattributes including medical and sexual

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maturity status, physical size, fitness,and skill proficiency (81).

Although bio-banding strategies havebeen designed and implemented ingood faith, there is limited evidencethat they are effective in reducinginjury risk, increasing competitiveequity and/or optimizing athleticdevelopment. This criticism is, how-ever, more representative of anabsence of scientific inquiry into thepotential benefits of bio-banding ratherthan the presence of contrary evi-dence. Nevertheless, growing concernsregarding the impact of mismatches insize and maturity upon athlete devel-opment, welfare, and safety have led toa renewed interest in this subject.Across a range of sports, researchersand practitioners are beginning toexplore the broader application ofbio-banding strategies with particularinterest in how assessments of biolog-ical maturation may be used to informtalent identification and development,including the provision of strength andconditioning. In this context, the pur-pose of this review is to describe someof the novel ways in which bio-banding is being reconsidered andintroduced in youth sports, and howit might be used to optimize athleticdevelopment and reduce the relativerisk of injury (Figure 1).

BIO-BANDING FOR MATURITY

Bio-banding strategies have tradition-ally grouped athletes on the basisof physical size. In recent years, how-ever, researchers and practitioners

have begun to explore the potentialbenefits of grouping players by matu-rity status, which raises the questionof how to best assess biological matu-rity status. Assessments of secondarysex characteristics and skeletal ageand estimates of age at PHV areimpractical for use in youth sports.However, 2 noninvasive and feasibleanthropometric methods for estimat-ing maturation have been advancedfor use with young athletes—the per-centage of predicted adult stature andthe maturity offset. The former is anestimate of maturity status, whereasthe latter is an estimate of maturingtiming, specifically time before PHV,which can be used as an estimate ofstatus, that is, pre- or post-PHV.

Using percentage of predicted adultstature at the time of observation(41,58,64,74), it is possible to groupathletes into maturity categories. Thedistribution of stages of pubic hair (PH)relative to four bands for percentages ofpredicted mature height attained at thetime of observation illustrates thepotential utility of this approach (Tableand Figure 1). The data are for soccerplayers 11.0–15.25 years of age atobservation. Although numbers arelimited, the majority of players withpercentages of predicted adult height(PAH) ,85.00% and $85.00 to,90.00% are, respectively, prepubertal(PH 1) and early pubertal (PH 2). Themajority of players with percentages ofPAH$90.00 to,95.00% and$95.00%are, respectively, mid-pubertal (PH 3)and late pubertal (PH 4). Similarly,

PHV tends to occur between 88 and96% of adult height, peaking at approx-imately 92% (7).

Percentage of predicted mature heightis not an indicator of growth velocity,although it can be used to indicatewhether a youngster may be progress-ing through the adolescent growthspurt. As noted, evidence collectedfrom longitudinal data indicate thatPHV occurs at approximately 91–92%of adult stature (7,80), with the lineargrowth spurt lasting approximately24–26 months (i.e., 61 year fromPHV) (78). Applying a band of 1 yearbefore and after PHV to longitudinalreference data (80), the onset of theadolescent growth spurt (i.e., point ofinflection fromminimal growth velocityin childhood) would be expected tooccur at approximately 88–89% of adultstature before returning to pre-growthspurt velocity (i.e., rate at take-off ) at95–96%. Applying these criteria, it ispossible to group athletes as beingpre-, circa-, and post-growth spurt. Es-timates of percentage of PAH and groupassignment should, nevertheless, becross-referenced with concurrent meas-ures of growth velocity. Growth veloc-ities during the adolescent growth spurtrange between 5 and 11 cm in malesand 5 and 9 cm in girls. If, for example,a male athlete is at 91% of theirPAH and presents a growth velocityof 8 cm per year, it is likely thatthey are currently experiencing theiradolescent growth spurt. In contrast,an athlete at 98% of PAH and present-ing a growth velocity of 1 cm per year-would be considered post-growth spurt.

The accurate measurement of chro-nological age, height, and weight ofthe youth players and of biologicalmid-parent height is central to theprotocol for estimating predictedadult stature. As such, it is importantthat those responsible for taking suchassessments are appropriately trainedand qualified. Reported parentalheights, adjusted for the tendencyfor overestimation, have been usedin several research studies, althoughthe suitability of this method needsfurther evaluation. There is alsoFigure 1. A contemporary model of bio-banding for youth sports.

Bio-banding in Sport

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a need for further refinement ofheight prediction equations.

Predicted age at maturity offset (timebefore or after PHV) and in turn age atPHV (age at prediction minus offset)provides an indicator of maturity tim-ing (65). This method is based on thepremise that youth who are advancedor delayed in maturation will experi-ence PHV at an earlier or later thanexpected age, respectively. Mean ageof PHV is, on average, about 13.8 yearsin boys and 11.9 years in girls (8).Although predicted maturity offsetwas suggested as a categorical variable,that is, an indicator of maturity status:pre-PHV (.1 year before PHV),circa-PHV (61 year from PHV), orpost-PHV (.1 year after PHV), it isoften used as an indicator of maturitytiming. The accuracy and reliability ofthe method has been questioned(57,59,60). Predictions are dependenton age and body size at predictionand have reduced variation comparedwith actual ages at PHV. They are alsoinfluenced by individual differences inactual ages of PHV, especially amongearly and late maturing youth. Amongearly maturing boys and girls, pre-dicted ages at PHVare later than actualage at PHV, whereas among latematuring boys and girls, predicted agesare earlier than actual ages at PHV

(57,59,60). Intraindividual variation inpredicted ages at PHV is also consider-able. Similar limitations have beennoted for the modified predictionequations (67) in an independent lon-gitudinal sample of boys (42).

Accordingly, practitioners using thematurity offset method should inter-pret their findings with caution andrecognize the limitations of the pro-tocol. Validation studies to date sug-gest that predicted age at PHV orclassifications of pre-, circa-, orpost-PHV status may be useful nearthe time of actual PHV in averagematuring boys within a relativelynarrow age range, circa 14.0 6 1.0years (57,59). Of note, many early-and mid-adolescent male athletesare advanced in skeletal and pubertalmaturation (61). Corresponding datafor girls are less clear. Predicted ageat PHV seems to be useful amongsome average and some late matur-ing girls (54,60). A more completeand critical discussion of both inva-sive and noninvasive methods ofmaturity assessment is beyond thescope of this discussion (54).

BIO-BANDING AND COMPETITION

Competition is an integral componentof youth sports programs and is inher-ently neither good nor bad (36).

Competitive inequity arising from mis-matches in size and/or maturity can,however, serve to impede the develop-ment of both early and late maturingboys (61). Athletes who mature inadvance of their peers experiencea competitive advantage in some sportsbecause of their superior size and ath-leticism (56). Although early develop-ers initially experience more success, itcan also be argued that they simulta-neously experience less challenge. Asa consequence, the early developingathlete is often ill prepared forfuture competition against physicallymatched and/or more mature oppo-nents. The competitive and selectivenature of many youth sports programsmay also encourage the early devel-oper to play to their physical strengthsat the neglect of his or her technicaland tactical skills (61). A failure to useor develop these skills during a devel-opmental stage (i.e., childhood andadolescence), in which neural path-ways are strengthened or removed,may have important implications forlearning and future performance(13,14). The consequences of suchactions may be most evident in lateadolescence and early adulthood, whenmaturity-associated differences in sizeand function are either attenuated or insome cases, reversed (47). Collectively,

TableCorrespondence between pubertal status (stage of pubic hair) and somatic maturation as assessed by percentage of

adult stature in Portuguese youth soccer players aged 11–15 years

Pubic hair stage

Percentage of PAH bands

Total no. of players,85% PAH 85–90% PAH 90–95% PAH 95–100% PAH

1 40 7 0 0 47

2 15 23 4 1 43

3 1 6 20 8 35

4 0 0 7 25 32

5 0 0 0 2 2

Total 56 36 31 36 159

PAH 5 predicted adult height.

Calculated by Robert M. Malina with permission from data reported in the study by Figueiredo et al. (31). The analyses presented in this table arebased upon data provided by Dr Antonio J Figueiredo, University of Coimbra, Portugal.



these factors may help explain whythose athletes identified as the most ablein childhood often fail to meet expect-ations for success as adults.

Athletes who mature in delay of theirpeers are at a distinct disadvantage insports that demands size, speed,strength, and power (56). As a conse-quence, late maturing players are lesslikely to experience success and/or beidentified as talented. Even if the laterdevelopers are selected, they are lesslikely to play key roles or positionsand impact the game (61). It can beargued that the greater challenge asso-ciated with being the youngest and/orleast mature serves as a stimulustoward superior long-term develop-ment. This argument was firstadvanced by Krogman (45) and isembedded in the “underdog hypothe-sis” of Gibbs et al. (34), which statesthat those youth who experience thegreatest physical challenges are morelikely to develop the technical andpsychological attributes necessary forsuccess at the adult professional level.The argument only holds, however, ifthe challenge is manageable and if theathlete is recruited into and/or re-tained by the system. At the elite level,the level of challenge associated withbeing the youngest and/or leastmature within an age group is signifi-cant. In a sample of academy soccerplayers at a professional club, playerswho were late maturing and born inthe fourth quarter of the competitiveage group (i.e., youngest) were 20times more likely to be deselected(39). This observation is particularlyconcerning when one considers thefact that neither date of birth normaturity timing are an attribute overwhich the athlete has control.

Research pertaining to the potentialbenefits of bio-banding is limitedand largely restricted to sports inwhich grouping athletes by age andweight-based criteria is an establishedpractice. Evidence from combatsports suggests that weight-based cri-teria can eliminate potential selectionand performance biases toward olderand/or more mature athletes. The

absence of a relative age effect injunior boxing has been attributed tothe grouping of athletes for competi-tion by a combination of both ageand weight-based criteria (26). Therelative age effect is also absent inother combat sports that use ageand weight-based criteria, for exam-ple, Olympic taekwondo and judo(1), with the exception of the “heavy”category in judo where a slight over-representation of athletes born in thefirst half of the competitive year isnoted. Although the results of thesestudies are suggestive, it should benoted that relative age is not an indi-cator of maturation. It reflects, onaverage, age differences among youthin the same chronological age year(e.g., 13.50–14.49 or 14.00–14.99years of age). Accordingly, selectionbiases toward early maturing athletesmay still exist within these sports,especially at the more elite levels.The impact of weight categories onplayer selection/development andsafety in contact sports such as Amer-ican football and rugby is largelyunknown, although observations forAustralian rugby suggest that discrep-ancies in player size do not serve asa risk factor for injury (43).

A CASE STUDY EXAMPLE OF BIO-BANDING FROM THE PREMIERLEAGUE ACADEMY SYSTEM

The English Premier League hasbeen a front-runner with regards to

the recent interest in the applicationof growth and maturation to long-term athlete development. As part ofthe Elite Player Performance Plan(EPPP) in English soccer, the leaguerecently trialled a bio-banded soccertournament, in which players weregrouped on the basis of biologicalmaturity status rather than age(Bengsch VA. Step forward? Kids inBritish Premier League academy trainbased on physical maturity. Availableat: https://www.researchgate.net/blog/post/a-step-forward-kids-in-british-premier-league-academy-train-based-on-physical-maturity. Accessed:September 15, 2016) (22). Using per-centage of predicted adult stature asthe index of maturity status, teamsparticipating in the tournament wererestricted to fielding players agedbetween 11 and 14 years and whosepercentage of predicted adult staturefell between $85.0 and ,90.0%. Thisband represents the transition fromlate-childhood to adolescence, that is,early puberty (Table and Figure 2). It isimportant to note that clubs wereadvised to consider both the psycho-logical and the technical developmentof players when selecting their teams.

Players’ experiences and perceptions ofcompeting in the bio-banded tourna-ment were captured in a series of focusgroups (Bengsch VA. Step forward?Kids in British Premier League academytrain based on physical maturity. Avail-able at: https://www.researchgate.net/

Figure 2. Bio-bands of maturity for an individual male based on cumulative growthand percentage of adult height.




blog/post/a-step-forward-kids-in-british-premier-league-academy-train-based-on-physical-maturity. Accessed:September 15, 2016) (22). Early and latematuring players described their ex-periences as positive and agreed thatthe bio-banded games presentedthem with unique challenges anda more diverse learning experience.They also recommended that thePremier League should integratebio-banded games within the exist-ing games program and continue tosupport this initiative. Their reasonfor supporting the initiative varied,however, relative to their matura-tional status. Early maturing playersdescribed the games as physicallymore challenging and found thatthey had to adjust their game empha-sizing technique, teamwork, and tac-tics over physicality. They alsodescribed the games as ideal prepa-ration for competing at the adultlevel and as an opportunity to learnfrom, and be mentored by, olderplayers.

As expected, late maturing playersdescribed their experience as lessphysically challenging. They did,however, see benefits from havingmore opportunity to use and demon-strate their complete skills set (i.e.,physical technical and tactical),impact and take control of the game,and adopt positions of leadership. Itshould be noted that while the earlyand late maturing players unani-mously supported the introductionof bio-banded games, they alsobelieved that bio-banding shouldserve as an adjunct to, and not asreplacement for, age-group competi-tion. Coaches also described theirexperiences as positive and encour-aged the Premier League to includemore opportunities for bio-bandingwithin the existing games program(Bengsch VA. Step forward? Kidsin British Premier League academytrain based on physical maturity. Avail-able at: https://www.researchgate.net/blog/post/a-step-forward-kids-in-british-premier-league-academy-train-based-on-physical-maturity. Accessed:

September 15, 2016) (22). More spe-cifically, bio-banding was viewed asproviding players with a more variedtraining program and a more diverseset of challenges and learning experi-ences, contributing to the holisticdevelopment of the athlete. Coachesalso noted that the tournaments chal-lenged them to “think differentlyabout our players” and gave them anopportunity to evaluate the players’skills and attributes in a more evenlymatched environment (22).

Although the results of this initialbio-banding venture show promise,further research is required to fullyunderstand the potential benefitsand limitations of such initiatives.The impact of bio-banded competi-tions on player performance andevaluation is of particular interest.Application of new technologies suchas GPS and performance analysissoftware will permit the examinationof the impact of bio-banding upon in-game indicators of performance, forexample, peak speed, distance cov-ered at speed, and involvement in sin-gular and repeated high-intensityactivities, among others. It shouldalso be noted that while the PremierLeague has the financial and logisticalresources to introduce and poten-tially benefit from bio-banding, thesestrategies may be more challenging toimplement at the grass roots or locallevels. Nevertheless, there is no rea-son that strategies aligned with theprinciples of bio-banding could notbe considered. In many youth sportsprograms, for example, it is commonfor early and late maturing athletes tobe encouraged to play up or, toa lesser extent, play down an agegroup if it is felt that this will aid inthe athlete’s development and if theathlete is psychologically and sociallyprepared for such a transition. Itshould be noted, however, that ath-letes playing up or down an age groupwill still have to contend with the sig-nificant variances in athlete size andmaturity that exist with chronologicalage groups.

BIO-BANDING AND TALENTIDENTIFICATION

The identification and confirmation(i.e., validation) of talented young ath-letes is a primary objective of mostprofessional sports clubs, national gov-erning bodies, and many intercolle-giate sport programs in the UnitedStates. Talent is commonly definedon the basis of success and/or athleticaptitude within competitive agegroups (83). However, the entire pro-cess of identification and developmentis superimposed on the demands ofphysical growth, biological maturation,and behavioral development and theirvarious interactions.

Individual differences in biologicalmaturation directly and indirectlyimpact the process of talent identifi-cation (24). Direct effects reflect theimmediate impact of variance inphysical and functional attributesupon athletic success, whereas indi-rect effects reflect the psycho-socialinterpretation and management ofgrowth and maturation, by the indi-vidual athlete and the adults (e.g.,coaches, managers) who direct spe-cific sports programs. The body andfunctional characteristics hold signif-icant social stimulus value for thoseinvolved in the identification anddevelopment of young athletes(23,66). More to the point, youth withthe physical and functional attributesdeemed most appropriate for successin a given sport are more likely to beencouraged and rewarded for theirparticipation, obtain more playingtime and opportunity to play impor-tant positions (i.e., captain), andreceive greater access to specializedcoaching and training resources (17).Conversely, youth who may beequally talented yet physically lessgifted, due to delayed maturation,are less likely to experience successand more likely to be overlooked orexcluded (20).

Talent identification strategies that favoryouth on the basis of attributes not fullyrealized until adulthood (i.e., maturesize and build, technical and tacticalskills) may be counterproductive in the



long term. There is a risk in overinvest-ing in youth who are physically mostcapable at the expense of those whomay have the most potential asadults. As previously noted, maturity-associated differences in size and func-tion observed in adolescence are oftenattenuated or reversed in adulthood(47). Selection gradients toward theselection of youth of specific maturitystatus have been documented in a num-ber of sports and tend to increase withage and competitive level (52,53). Thereis, however, limited evidence to suggestthat ability or success in late childhoodand adolescence is predictive of successat the adult level. A 7-year follow-up ofGerman athletes across 7 Olympicsports found that only 15 of 4,972(0.3%) of those selected at the youngestlevel in each sport eventually rankedamong the 10 best international seniorathletes (35). Furthermore, a 3-yearfollow-up analysis noted that only 192of 11,287 athletes in elite sport schools(1.7%) attained a medal in an interna-tional championship as adults. Thesefindings highlight the importance ofencouraging multiple sports participa-tion in youth and providing a varied/sampling training stimulus that teachesa broad range of movement skills andprepares athletes for success acrossa range of activities.

The biggest risk was that we had erred inour assessment of a particular boy andcould have used his slot to work witha more talented youngster. We had to waita little longer to see the real potential insome boys, because not everyone’s physiquedevelops at the same rate.

—Sir Alex Ferguson, former manager ofManchester United Football Club (29,p. 260) author

Observations from studies of the rel-ative age effect provide some addi-tional insights. Youth soccer playersenrolled in the talent developmentprogram of the German FootballAssociation who were born in thefirst quarter of the competitive year(January–March) presented thehighest absolute mean values ona composite index of athletic aptitude

(85). However, the scores fell belowthe median value for age when com-pared against the developmentalcurve for age, that is, the oldestplayers performed the best withintheir age group but were the weakestwhen evaluated relative to thedevelopmental curve. Conversely,players born late in the competitiveyear (October–December) presentedthe lowest mean scores within theircompetitive age groups, yet scoredwell above the median when consid-ered relative to the developmentalcurve. The largest differences inabsolute athletic aptitude scores wereobserved between those players bornat the start of the competitive yearand the players born a month earlier(i.e., December) in their next oldestage group. The observation is seem-ingly consistent with the “underdoghypothesis,” which suggests thatyounger and/or later maturing ath-letes need to be physically, techni-cally, and psychologically “ahead ofthe curve” to remain competitivewithin such programs (34). The re-sults also suggest that older and/orearly maturing males get by on theirphysical prowess rather than theirtechnical or tactical abilities.

CASE STUDY EXAMPLES OF BIO-BANDING FOR TALENTEVALUATION

As part of the EPPP for U.K. soccer,all Premier League and category 1academies conduct a standardizedseries of fitness tests on a tri-annualbasis (22). The data from each club isentered into the Premier League’sPlayer Management Application andused to generate league-wide age-and maturity-specific reference. Ona similar basis, the British Lawn Ten-nis Association (LTA) (Science couldhelp search for the next Andy Murray.Available at: http://www.bath.ac.uk/news/2016/07/04/tennis-biobanding/.Accessed: September 15, 2016)and Bath Rugby Football Club (Atkin-son M. Bio-banding in the academy.Available at: http://www.bathrugby.com/academy-news/bio-banding-in-the-academy/. Accessed: September 15,

2016) combine maturation and fitnessdata to generate age- and maturity-specific references. Use of these refer-ences permits the banding and/orconsideration of athletes by bothchronological age and maturity statuswhen assessing fitness. The strategyshould also enable coaches and practi-tioners to better account for individualdifferences in maturation when evalu-ating athletic ability and potential, andhelp to identify previously unseenstrengths and weaknesses in their ath-letes. The benefits of considering ath-letic performance and/or fitnessrelative to both age- and maturity-specific standards are illustrated inFigures 3 and 4. In Figure 3, the per-formances of an early maturing 12-year-old male soccer player (playerA) on a series of physical fitness testsare plotted relative to reference stand-ards derived from players of the samechronological age. Considering theathletic advantages associated withadvanced maturation in males, it isnot surprising that player A scores con-sistently above the mean on tests ofspeed, power, agility, and aerobiccapacity when compared with hissame-age peers. When player A’s per-formance is compared against stand-ards derived from youth of the samebiological maturation, however, wesee a much different pattern of results(Figure 4). In this instance, player A’sfitness scores only approximate and, insome instances, fall below the mean(i.e., agility and aerobic capacity),revealing previously unidentified weak-nesses. Conversely, a late maturing ath-lete, who may not appear exceptionallyfast or strong compared with same agepeers, may present a much more favor-able performance compared againsttheir maturational peers.

To better monitor long-term changesin the functional capacity of juniortennis players, the LTA is currentlyworking with the Institute for Mathe-matical Innovation at the University ofBath to generate age- and maturityspecific developmental trajectories forfitness (Science could help search forthe next Andy Murray. Available at:




http://www.bath.ac.uk/news/2016/07/04/tennis-biobanding/. Accessed:September 15, 2016). Developmentaltrajectories for fitness should enablepractitioners to better monitor athletedevelopment while taking individualdifferences in maturation into account.The trajectories may also help identifyperiods of acceleration and stagnationand in the partitioning of training-related gains from those that occur as

a result of normal growth and matura-tion. Although the development of age-and maturity-specific references againstwhich a young athlete can be com-pared represent a step in the right direc-tion, it is important to recognize thatfunctional capacities (peak V̇O2, staticstrength, power, and speed) also haveadolescent growth spurts that vary, onaverage, relative to the timing of PHVin boys and girls (10,11,56,69).

Recognizing that a selection bias towardolder and/or more mature soccer play-ers exists as part of the scouting process,a number of English and Scottish pro-fessional soccer clubs have hosted trialsrestricted to youth born in the last quar-ter of the competitive year (15). Simi-larly, a study conducted with the PSVEindhoven’s soccer Academy demon-strated that scouting biases towards rel-atively older players can be mitigatedthrough the use of age-ordered shirtnumbers (62). These strategies and per-haps others attempt to address the rel-ative age bias in athlete recruitment. Theoverall effectiveness of such strategiesmay be limited, however, as they donot account for variation in maturity sta-tus, as noted in the report (62).

Individual differences in maturity statusare not dependent on the calendar.Within a single chronological year, forexample, 11.0–11.99 years or 13.0–13.99years, late, average, and early maturingplayers are observed within each birthquarter. A player born late in the year,yet who is advanced in maturation, maynot be expected to struggle in a compe-tition within their own age group;whereas a player born early in the yearwho is late in maturation may not beexpected to possess an athletic or sizeadvantage over his same age peers. Itshould be also noted that the relativeage effect is a population-based phe-nomenon reflecting appropriation ofathletes of various ages across an orga-nization and, as noted earlier, shouldnot be considered a proxy for maturitystatus in individual athletes. Neverthe-less, organizations and practitionersneed to consider how some of theseaforementioned strategies could be usedto counter selection biases toward olderand/or more mature players in thescouting process.

BIO-BANDING AND STRENGTHAND CONDITIONING

Although bio-banding was initiallyproposed for matching athletes incompetition, it also has potential rele-vance in the context of strength andconditioning. Practitioners have longbeen encouraged to accommodate

Figure 4. Player A’s fitness attributes represented as Z-scores relative to players of thesame maturity status.

Figure 3. Player A’s fitness attributes represented as Z-scores relative to players of thesame chronological age.



individual differences in growth andmaturation when designing, imple-menting, and evaluating training andconditioning programs for young ath-letes (76). In childhood, for example,gains in strength, speed, and powerare best achieved through activities thatencourage adaptations of the neuro-muscular systems, whereas postpuber-tal youth are more able to becomestronger, faster, and powerful throughmuscle fiber hypertrophy and increasesin the cross-sectional area of muscle(50). It has also been suggested thatthe adolescent growth spurt is a periodof increased risk for overuse injuries andthat training and recovery should bemore carefully monitored and adjustedduring this phase of rapid growth(28,63,70). It remains unclear, however,whether the growth spurt, per se, or thecumulative effect of a range factorsrelated to age, size, and maturity—behavioral changes, training volume,changes in the nature of competition,and perhaps others—contributes to theincreased risk of injury. Furtherresearch is clearly warranted.

To optimize training effects and ensureathlete safety and well-being, practi-tioners should consider individual differ-ences in maturity status (51). The LongTerm Athlete Development (LTAD)Model was the first model of athletedevelopment to gain worldwide recog-nition and was adopted and imple-mented by numerous organizationsworking with young athletes (4). TheLTAD model proposed that thedevelopment of young athletes couldbe accelerated and optimized byimplementing the most appropriatetraining stimuli at specific phases of mat-urational development known as “win-dows of opportunity.” The authorsproposed that through the assessmentand monitoring of the pubertal growthspurt, it was possible to adapt trainingprograms relative to their stage of devel-opment of individual athletes, therebymaximizing potential benefits. Althoughthe concept of matching training relativeto maturity status is intuitively appeal-ing, the LTADmodel has been criticizedon several accounts (32). Key criticisms

included the use of chronological agegroups and not maturational bands fordefining key phases of development,limited evidence to suggest that a failureto exploit windows of opportunity in-hibits athletic development, and too lateof an emphasis upon muscular strengthdevelopment (50). A further limitationof the LTADmodel was the lack of con-sideration of growth spurts in other di-mensions and functions, in addition tooveremphasis on the importance of theadolescent growth spurt.

Addressing the limitations of the LTADmodel, an alternative paradigm namedthe Youth Physical Development(YPD) model has been advanced (50).The YPD model offers a more compre-hensive and detailed framework forunderstanding athlete development inyouth and the impact of maturationon trainability in children and adoles-cents. A key tenet of the YPD model isthat all fitness attributes are responsiveto training throughout childhood andadolescence. The most efficacioustraining modes are, however, those thatcomplement physiological adaptations,which occur as a result of growth andmaturation. Referred to as “synergisticadaptation,” the principal holds that theathletes’ training program (assumingtechnical competence has beenachieved) should expose athletes totraining stimuli that complement theirstage of maturation (49). Beforepuberty, optimal strength gains instrength and power are achievedthrough enhanced neural coordination.Maximum gains in strength and powerduring and after puberty are achievedthrough a combination of both neuraland structural adaptations, with thelatter resulting from a combination offactors, including hormonal and meta-bolic changes, training stimuli, andnutrition (32). From a bio-bandingperspective based on PAH, youth,85% would be considered prepuber-tal (Table) and training programswould be designed to primarily facili-tate positive neural adaptations toenhance force, speed, and power.Youth between 89 and 95% of PAHwould be in the mid to late stages of

puberty and thus programs shouldbe modified to facilitate both neuraland structural changes. Youth at 95%PAH and beyond would be postpuber-tal and more capable of achieving sub-stantial performance gains throughhypertrophy.

Through the consideration of individualdifferences in maturation and the provi-sion of developmentally appropriatetraining programs, practitioners may beable to reduce the risk of injuries relatedto growth and training load. The adoles-cent spurt is often indicated as an inter-val during which youth are moresusceptible to overuse and growth-related injuries (18,19,28,40,63,70). Theprevalence of apophyseal injuries, suchas Osgood Schlatter’s disease and Sever’sdisease among youth soccer playerspeaks during and just before the adoles-cent growth spurt, respectively, follow-ing a curve that is very similar to that ofgrowth velocity in stature (70). The ear-lier increase in the incidence of Sever’sdisease may reflect the fact that thegrowth spurt in the foot typically occurs6 months in advance of the lower andupper segments of the legs. In line withthis reasoning, an increased risk of over-use injuries in Dutch Academy soccerplayers were noted in the year beforeand during predicted age at PHV (84).Additional risk factors for such injuriesinclude sex (i.e., being male), neuromus-cular control, overtraining, and participa-tion in sports that require running,jumping, and sudden changes of direc-tion (73).

Through regular assessment of growthand maturity status, in addition to con-comitant risk factors, practitioners canbetter identify intervals of greater risk ofinjury and adjust training programsaccordingly. Such strategies may beparticularly beneficial for the earlymaturing athlete who may experiencea more intense growth spurt and thelate maturing athlete who experienceshis or her growth spurt at an age whenthe demands of training and competi-tion are typically greater and in turnmay enhance the risk of injury (84).Consistent with this hypothesis, balletinstructors argue that early maturation




is favorable for dancers in that it “gets thegrowing out of the way” at an age whentraining demands are lower and beforeimportant phases of evaluation andselection (66). On a similar basis, de-layed maturation in female gymnastshas been identified as a potential riskfactor for chronic spine injuries asa result of prolonged exposure of thegrowth plates to unfavorable mechani-cal factors, such as repetitive pressures,microtrauma, and impacts (79,87).Through the application of bio-banding, it may be possible to accom-modate individual differences in thematurity status of young dancers andadjust training and evaluation practicesaccordingly. Dancers going through thegrowth spurt might have their trainingload adjusted to place a greater empha-sis on quality and diversity in contrast toquantity while corresponding adjust-ments and assessments may be delayeduntil after the growth spurt in latermaturing dancers.

Bio-banding may also be used to betteridentify and accommodate athleteswho experience decreases in move-ment skills during the adolescent spurt.Commonly referred to as “adolescentawkwardness,” some evidence suggeststhat the rapid changes in size and pro-portions that accompany the pubertalgrowth spurt coupled with changes inhow the brain processes informationabout body positioning (12,71) mayadversely impact neuromuscular con-trol and proprioceptive ability duringthe interval of rapid growth. Althoughempirical evidence remains somewhatlimited, it has been argued that decre-ments in neuromuscular control duringthe growth spurt result in a decline inmotor and functional performances (9),a need to relearn motor skills (18), andan increased potential risk of injury(12,18,19,37,69,72). Similarly, it hasbeen argued that an asynchronybetween rates of growth in standingheight and bone mass accumulation,occurring between stages 2 and 3(PH) of puberty, may predispose youthto a high incidence of fractures duringthis period (3,16,33,46).

To alleviate the potential impact ofgrowth and maturation on skill perfor-mance, practitioners should routinelyscreen athletes to identify any notabledeficiencies in fundamental movementskills, especially during the phase ofrapid growth. The observation of ath-letes in training and competition wouldalso help determine the extent towhich any such changes impact theperformance of sport-specific skillsand/or present an increased risk ofinjury. Note, however, that not all indi-viduals experience decrements in per-formance during the adolescentgrowth spurt. Likewise, not all decre-ments in performance can be attributedto the growth spurt and may arise fromtraining overload, competing interests,lack of motivation, or poor coaching.

Athletes entering phases of rapiddevelopment should also be educatedon the potential risks to skill perfor-mance and their training programsshould be adjusted accordingly (18).Both education and implementationshould be delivered by individuals (e.g., coaches, sports scientists, or medi-cal staff ) who have been trained in theassessment and interpretation ofgrowth and maturity status and whooperate as part of a multidisciplinaryand integrated athlete support pro-gram. A variety of strategies might beimplemented to mitigate the effects ofgrowth on skill performance, includingthe integration of fundamental move-ment skills in warm-ups and technicalsessions, a greater emphasis on move-ment skills training and a reducedemphasis on performance gains (i.e.,quality over quantity), the use ofvisual and kinesthetic feedback, con-trolled movement, reaction andmotor co-ordination training, andthe retraining of functional abilities(i.e., running, lifting, and jump-landing mechanics) (15).

CASE EXAMPLES OF BIO-BANDING FOR TRAINING

When assigning athletes to variousbands based on maturity status, it isimportant to initially consider the resis-tance training competence and/or psy-chological maturity (i.e., cognitive and

emotional) of the individual athlete.For example, an integrated 3-step pro-cess for bio-banding athletes for thepurpose of training had been advo-cated; it includes the assessment oftechnical, psychological, and matura-tional development before the athleteis assigned to a specific training group(15). A number of professional soccerclubs in England are already using as-sessments of biological maturation andtechnical competence are to groupplayers for the purpose of conditioning(27). Such approaches can also be usedto create individualized developmen-tally appropriate training programsfor young athletes.

A progression model (e.g., bronze, sil-ver, gold, platinum), whereby individ-uals are graded on the basis of theirtechnical, psychological, and matura-tional attributes, may facilitate theassessment and monitoring of a youngathlete’s “readiness” to move into andthrough different stages of a trainingprogram (e.g., bronze level 5 poortechnical competency, prepubertal,psychologically immature; platinum5 high technical competency, postpu-bertal, psychologically mature). Astage-based progression model canalso help practitioners to monitor andaddress potential regressions in techni-cal competency in some athletes,which may be related to the adolescentgrowth spurt (i.e., awkwardness). Acoach might, for example, encouragean athlete to revisit a particular stage(e.g., silver to bronze) should theyexperience a sudden decrement intechnical competence. Such modelsshould emphasize the holistic develop-ment of the young athlete and any de-cisions to move an athlete up or downa level should be made on the basis ofscientific evidence and input froma specialist practitioner/integratedsports performance team.

SUMMARY

The practice of bio-banding is receiv-ing renewed interest in the context ofyouth sports and is being applied ina variety of contexts (i.e., competition,training, assessment). Emerging evi-dence suggests that bio-banding, as



an adjunct to age group competition,can benefit both early and late matur-ing players in academy soccer. Furtherresearch is required to replicate thefindings and evaluate the extent towhich they may generalize to differentsports or samples. Some evidence sug-gests that bio-banding may also haveapplication to the training of youngathletes and the processes of talentidentification and confirmation. Moreresearch is, however, required to sub-stantiate these positions.

Although the process of bio-bandinghas the potential to contribute posi-tively to the experiences and develop-ment of young athletes, it is importantto recognize that it is not a panaceaand that it should operate as part ofa multifaceted and holistic programof development. Bio-banding is oneof many tools that can be used to bet-ter understand and promote the devel-opment and well-being of youngathletes. It is not a substitute for agegroup training or competitions; rather,bio-banding is an adjunct activity thathas the potential to challenge the ath-lete in a unique manner and to createa more diverse and developmentallyappropriate learning environment. Inline with this reasoning, a more effec-tive athlete development programmight include the provision of bothage group and bio-banded activities,which offer athletes a more diverse,multifaceted, and developmentallysensitive learning stimulus. A “hybridapproach” (82) might involve monthlyor bimonthly bio-banded competitionsas part of the existing game program.Such a system would retain the ben-efits of age group competition whilesimultaneously addressing its limita-tions. It would also expose athletes toa broader range of challenges andlearning contexts, which may opti-mize athlete development, skillacquisition, and welfare. A hybridapproach would also permit coachesand scouts to assess abilities andpotential of athletes across a widerrange of learning environments.

Finally, bio-banding competition,much like age-group competition, hasits limitations. Maturity assessmentsapplicable to field conditions need fur-ther study and validation. Biologicalgrowth and maturation and psycho-logical and social development donot progress in synchrony. Knowinghow to best assess and evaluate biolog-ical, psychological, and social readi-ness is essential for improving theeffectiveness of bio-banding strategies.Bio-banding, as both a practice andtopic of scientific inquiry, is also stillin its infancy. Thus, more research isneeded to determine its effectivenessand understand its limitations.

Conflicts of Interest and Source of Funding:The authors report no conflicts of interestand no source of funding.

Sean P.

Cumming isa senior lecturerin Sport andExercise Sciencesat the Universityof Bath.

Rhodri S. Lloyd

is a senior lec-turer in strengthand condition-ing and Chair ofthe Youth Phys-ical Develop-ment Centre atCardiff Metro-

politan University.

Jon L. Oliver isa reader inApplied Paediat-ric ExerciseScience and co-founder of theYouth PhysicalDevelopmentCentre at CardiffMetropolitan

University.

Joey C.

Eisenmann isthe director ofSpartan Perfor-mance in theCollege of Osteo-pathic Medicineat MichiganState University.

Robert M.

Malina is profes-sor emeritus inthe Departmentof Kinesiologyand HealthEducation at theUniversity ofTexas at Austin.

REFERENCES1. Albuquerque MR, Franchini E, Lage GM,

Da Costa VT, Costa IT, and Malloy-Diniz LF.

The relative age effect in combat sports: An

analysis of Olympic judo athletes, 1964–

2012. Percept Mot Skills 121: 300–308,

2015.

2. Albuquerque MR, Fukuda DH, Costa VT,

Lopes MC, and Franchini E. Do weight

categories prevent athletes from the

relative age effect? a meta-analysis of

combat sports. Sport Sci Health 12: 1–7,

2016.

3. Bailey DA, Wedge JH, Mcculloch RG,

Martin AD, and Bernhardson SC.

Epidemiology of fractures of the distal end

of the radius in children as associated with

growth. J Bone Joint Surg Am 71A: 1225–

1231, 1989.

4. Balyi I and Hamilton A. Long-term athlete

development: Trainability in childhood and

adolescence. Olympic Coach 16: 4–9,

2004.

5. Baxter-Jones ADG. Growth and

development of young athletes: Should

competition levels be age related. Sports

Med 20: 59–64, 1995.

6. Baxter-Jones ADG. Growth and maturation.

In:Paediatric Exercise Science andMedicine.

Armstrong N and Van Mechelen W, eds.

Oxford, UK: Oxford University Press, 2009.

pp. 157–168.




7. Baxter-Jones ADG. Growth, maturation,

and training. In: Handbook of Sports

Medicine and Science: Gymnastics. Caine

DJ, Russell KW and Lim L, eds. Chichester,

UK: John Wiley & Sons, Ltd, 2013. pp.

17–27.

8. Baxter-Jones ADG, Eisenmann JC, and

Sherar LB. Controlling for maturation in

pediatric exercise science. Pediatr Exerc

Sci 17: 18–30, 2005.

9. Baxter-Jones ADG, Thompson AM, and

Malina RM. Growth and maturation in elite

young female athletes. Sports Med Arth

Rev 10: 42–49, 2002.

10. Beunen GP and Malina RM. Growth and

physical; performance relative to the timing

of the adolescent spurt. Exerc Sport Sci

Rev 16: 503–540, 1988.

11. Beunen GP, Malina RM, Van’t Hof MA,

Simons J, Renson R, and Van Gerven D.

Adolescent Growth and Motor

Performance: A Longitudinal Study of

Belgian Boys. Champaign, IL: Human

Kinetics, 1988.

12. Bisi MC and Stagni R. Development of gait

motor control: What happens after

a sudden increase in height during

adolescence? Biomed Eng Online 15: 47,

2016.

13. Blakemore SJ. Brain development in

adolescence. J Neurol Neurosurg

Psychiatry 85: e3, 2014.

14. Blakemore SJ, Burnett S, and Dahl RE. The

role of puberty in the developing

adolescent brain. Hum Brain Mapp 31:

926–933, 2010.

15. Blanchard S. Bio-banding. Available at:

https://media.brighton.ac.uk/CRS2/Bio-

Banding_-_20150225_132718_11.html.

Accessed: September 15, 2016.

16. Blimkie CJR, Lefevre J, Beunen GP,

Renson R, Dequeker J, and Vandamme

P. Fractures, physical-activity, and

growth velocity in adolescent Belgian

boys. Med Sci Sports Exerc 25: 801–

808, 1993.

17. Bloom BS and Sosniak LA. Developing

Talent in Young People. New York, NY:

Ballantine Books, 1985.

18. Bowerman EA, Whatman C, Harris N, and

Bradshaw E. A review of the risk factors for

lower extremity oversue injuries in young

elite female ballet dancers. J Dance Med

Sci 19: 51–56, 2015.

19. Bowerman E, Whatman C, Harris N,

Bradshaw E, and Karin J. Are maturation,

growth and lower extremity alignment

associated with overuse injury in elite

adolescent ballet dancers? Phys Ther

Sport 15: 234–241, 2014.

20. Cobley S. Talent identification and

development in youth sport. In: Routledge

Handbook of Youth Sport. Green K and

Smith A, eds. Abingdon, United Kingdom:

Routledge, 2016. pp. 476–491.

21. Crampton CW. Physiological age: A

fundamental principle. Amer Phys Educ

Rev 8: 141–154, 1908.

22. Cumming SP and Bunce J. Maturation in

Playere Development and Practical

Strategies in Premier League Academies.

Rugby Football Union (RFU) Player

Development Conference: The Future

Player. Twickenham Stadium, United

Kingdom, 2015.

23. Cumming SP, Eisenmann JC, Smoll FL,

Smith RE, and Malina RM. Body size and

perceptions of coaching behaviors by

adolescent female athletes. Psychol Sport

Exerc 6: 693–705, 2005.

24. Cumming SP, Sherar LB, Pindus DM,

Coelho-e-Silva MJ, Malina RM, and Jardine

PR. A biocultural model of maturity-

associated variance in adolescent physical

activity. Int Rev Sport Exerc Psychol 5: 23–

43, 2012.

25. Cumming SP, Standage M, Loney T,

Gammon C, Neville H, Sherar LB, and

Malina RM. The mediating role of physical

self-concept on relations between

biological maturity status and physical

activity in adolescent females. J Adolesc

34: 465–473, 2011.

26. Delorme N. Do weight categories prevent

athletes from relative age effect? J Sports

Sci 32: 16–21, 2014.

27. Depledge M. Application of Growth and

Maturation at Southampton FC. Team

Bath Professional Development Seminar

Series: Bath, UK: University of Bath,

2015.

28. DiFiori JP, Benjamin HJ, Brenner JS,

Gregory A, Jayanthi N, Landry GL, and

Luke A. Overuse injuries and burnout in

youth sports: A position statement

from the American Medical Society for

Sports Medicine. Br J Sports Med 48:

287–288, 2014.

29. Ferguson A. Leading. London, United

Kingdom: Hodder & Stoughton, 2015.

30. Figueiredo AJ, Coelho Silva MJ, Cumming

SP, and Malina RM. Size and maturity

mismatch in youth soccer players 11-to 14-

years-old. Pediatr Exerc Sci 22: 596–612,

2010.

31. Figueiredo AJ, Goncalves CE, Silva MJCE,

and Malina RM. Youth soccer players, 11–

14 years: Maturity, size, function, skill and

goal orientation. Ann Hum Biol 36: 60–73,

2009.

32. Ford P, De Ste Croix M, Lloyd R, Meyers R,

Moosavi M, Oliver J, Till K, and Williams C.

The long-term athlete development model:

Physiological evidence and application.

J Sport Sci 29: 389–402, 2011.

33. Fournier PE, Rizzoli R, Slosman DO,

Theintz G, and Bonjour JP. Asynchrony

between the rates of standing height gain

and bone mass accumulation during

puberty. Osteoporos Int 7: 525–532,

1997.

34. Gibbs BG, Jarvis JA, and Dufur MJ. The rise

of the underdog? The relative age effect

reversal among Canadian-born NHL

hockey players: A reply to Nolan and

Howell. Int Rev Sociol Sport 47: 644–649,

2012.

35. Gullich A, Emrich E, and Schwank B.

Evaluation of the support of young athletes

in the elite sport system. Eur J Sport Soc 3:

85–108, 2006.

36. Hedstrom R and Gould D. Research in

Youth Sports: Critical Issues Status. East

Lansing, MI: Michigan State University,

2004. pp. 1–42.

37. Hewett TE, Myer GD, and Ford KR.

Decrease in neuromuscular control about

the knee with maturation in female athletes.

J Bone Joint Surg Am 86A: 1601–1608,

2004.

38. Hunter Smart JE, Cumming SP, Sherar

LB, Standage M, Neville H, and Malina

RM. Maturity associated variance in

physical activity and health-related

quality of life in adolescent females. A

mediated effects model. J Phys Act

Health 9: 86–95, 2012.

39. Johnson A. Growth and Maturation of

Youth Football Players: Medical

Considerations and Implications. Premier

League Performance Leadership

Conference. Silverstone, United Kingdom,

2015.

40. Kemper GLJ, van der Sluis A, Brink MS,

Visscher C, Frencken WGP, and Elferink-

Gemser MT. Anthropometric injury risk

factors in elite-standard youth soccer. Int

J Sports Med 36: 1112–1117, 2015.

41. Khamis HJ and Roche AF. Predicting

adult stature without using skeletal

age—the Khamis-Roche Method.

Pediatrics 95: 504–507, 1995.

42. Koziel SM and Malina RM. Validation of the

modified maturity offset equations in

a longitudinal sample of boys In

preparation.

43. Krause LM, Naughton GA, Denny G,

Patton D, Hartwig T, and Gabbett TJ.

Understanding mismatches in body size,

speed and power among adolescent rugby



union players. J Sci Med Sport 18: 358–

363, 2015.

44. Kreipe RE and Gewanter HL. Physical

maturity screening for participation in

sports. Pediatrics 75: 1076–1080,

1985.

45. Krogman WM. Maturation age of 55 boys

in the Little League World series, 1957.

Res Q 30: 54–56, 1959.

46. Landin L and Nilsson BE. Bone-mineral

content in children with fractures. Clin

Orthop Relat Res 178: 292–296, 1983.

47. Lefevre J, Beunen G, Steens G,

Claessens A, and Renson R. Motor-

performance during adolescence and

age 30 as related to age at peak height

velocity. Ann Hum Biol 17: 423–435,

1990.

48. Lintunen T, Rahkila P, Silvennoinen M,

and Osterback L. Psychological and

physical correlates of early and late

biological maturation in 9- to 11-year-old

girls and boys. In: Young Athletes:

Biological, Psychological, and

Educational Perspectives. Malina RM,

ed. Champaign, IL: Human Kinetics,

1988. pp. 85–91.

49. Lloyd RS, Cronin JB, Faigenbaum AD, Haff

GG, Howard R, Kraemer WJ, Micheli LJ,

Myer GD, and Oliver JL. The National

Strength and Conditioning Association

position statement on long-term athletic

development. J Strength Cond Res 30:

1491–1509, 2016.

50. Lloyd RS and Oliver JL. The youth physical

development model: A new approach to

long-term athletic development. Strength

Cond J 34: 61–72, 2012.

51. Lloyd RS, Oliver JL, Faigenbaum AD, Myer

GD, and De Ste Croix MBA. Chronological

age vs. biological maturation: Implications

for exercise programming in youth.

J Strength Cond Res 28: 1454–1464,

2014.

52. Malina RM. Children and adolescents in

the sport culture: The overwhelming

majority to the select few. J Exerc Sci Fit 7:

S1–S10, 2009.

53. Malina RM. Skeletal age and age

verification in youth sport. Sports Med 41:

925–947, 2011.

54. Malina RM. Assessment of biological

maturation. In: Oxford Textbook of

Children’s Sport and Exercise Medicine.

ArmstrongN and van MechelenW, eds.

Oxford, UK: Oxford University Press, In

press.

55. Malina RM and Beunen G. Matching of

opponents in youth sports. The child and

adolescent athlete. In: The Child and

Adolescent Athlete. Bar-Or O, ed. Oxford,

United Kingdom: Blackwell Science Ltd.,

1996. pp. 202–213.

56. Malina RM, Bouchard C, and Bar-Or O.

Growth Maturation and Physical

Activity. Champaign, IL: Human

Kinetics, 2004.

57. Malina RM, Choh AC, Czerwinski SA, and

Chumlea WC. Validation of maturity offset

in the Fels Longitudinal Study. Pediatr

Exerc Sci 28: 439–455, 2016.

58. Malina RM and Cumming SP. A non-

invasive method for estimating maturity

status. Application to young athletes.

Insight 6: 34–37, 2004.

59. Malina RM and Koziel SM. Validation of

maturity offset in a longitudinal sample of

Polish boys. J Sports Sci 32: 424–437,

2014.

60. Malina RM and Koziel SM. Validation of

maturity offset in a longitudinal sample of

Polish girls. J Sports Sci 32: 1374–1382,

2014.

61. Malina RM, Rogol AD, Cumming SP, Silva

MJCE, and Figueiredo AJ. Biological

maturation of youth athletes: Assessment

and implications. Br J Sports Med 49:

852–859, 2015.

62. Mann DL and van Ginneken PJ. Age-

ordered shirt numbering reduces the

selection bias associated with the relative

age effect. J Sports Sci 35: 784–790,

2017.

63. Mansfield MJ and Emans SJ. Growth in

female gymnasts—Should training

decrease during puberty. J Pediatr 122:

237–240, 1993.

64. Meylan CMP, Cronin JB, Oliver JL, Hopkins

WG, and Contreras B. The effect of

maturation on adaptations to strength

training and detraining in 11–15-year-olds.

Scand J Med Sci Sports 24: E156–E164,

2014.

65. Mirwald RL, Baxter-Jones ADG, Bailey DA,

and Beunen GP. An assessment of

maturity from anthropometric

measurements. Med Sci Sports Exerc 34:

689–694, 2002.

66. Mitchell SB, Haase AM, Malina RM, and

Cumming SP. The role of puberty in

the making and breaking of young

ballet dancers: Perspectives of

dance teachers. J Adolesc 47: 81–89,

2016.

67. Moore SA, Mckay HA, Macdonald H,

Nettlefold L, Baxter-Jones ADG,

Cameron N, and Brasher PMA.

Enhancing a somatic maturity prediction

model. Med Sci Sports Exerc 47: 1755–

1764, 2015.

68. Petersen AC and Taylor B. The biological

approach to adolescence: Biological

change and psychological adaptation. In:

Handbook of Adolescent Psychology.

Adelson J, ed. New York, NY: Wiley-

Interscience, 1980.

69. Philippaerts RM, Vaeyens R, Janssens M,

Van Renterghem B, Matthys D, Craen R,

Bourgois J, Vrijens J, Beunen G, and Malina

RM. The relationship between peak height

velocity and physical performance in youth

soccer players. J Sports Sci 24: 221–230,

2006.

70. Price RJ, Hawkins RD, Hulse MA, and

Hodson A. The football association medical

research programme: An audit of injuries in

academy youth football. Br J Sports Med

38: 466–471, 2004.

71. Quatman-Yates CC, Quatman CE,

Meszaros AJ, Paterno MV, and Hewett TE.

A systematic review of sensorimotor

function during adolescence: A

developmental stage of increased motor

awkwardness? Br J Sports Med 46: 649–

655, 2012.

72. Read P, Oliver JL, De Ste Croix MBA, Myer

GD, and Lloyd RS. Injury risk factors in

male youth soccer players. Strength Cond

J 37: 1–7, 2015.

73. Read PJ, Oliver JL, De Ste Croix MBA,

Myer GD, and Lloyd RS. Assessment of

injury risk factors in male youth soccer

players. Strength Cond J 38: 12–21,

2016.

74. Roche AF, Tyleshevski F, and Rogers E.

Non-invasive measurements of physical

maturity in children. Res Q Exerc Sport 54:

364–371, 1983.

75. Rotch TM. A study of the development of

the bones in children by roentgen method,

with the view of establishing

a developmental index for grading of and

the protection of early life. Trans Assoc Am

Physicians 24: 603–630, 1909.

76. Sanderson L. The importance of

considering growth and development when

designing and implementing training plans

for young athletes. World Athletics Symp

2: 88–95, 1989.

77. Sherar LB, Cumming SP, Eisenmann JC,

Baxter-Jones ADG, and Malina RM.

Adolescent biological maturity and physical

activity: Biology meets behavior. Pediatr

Exerc Sci 22: 332–349, 2010.

78. Stang J and Story M. Adolescent growth

and development. In: Guidelines for

Adolescent Nutrition Service. Stang J and

Story M, eds. School of Public Health,

Minneapolis and Saint Paul, Minnesota,

University of Minnesota, 2005. pp. 1–8.




79. Tanchev PI, Dzherov AD, Parushev AD,

Dikov DM, and Todorov MB. Scoliosis in

rhythmic gymnasts. Spine (Phila Pa 1976)

25: 1367–1371, 2000.

80. Tanner JM. Growth at Adolescence:

With a General Consideration of the

Effects of Hereditary and Environmental

Factors upon Growth and Maturation

from Birth to Maturity. Oxford, United

Kingdom: Blackwell Scientific

Publications, 1962.

81. The New York State Education

Department Office of Elementary,

Middle, Secondary and Continuing

Education. The New York state

selection/classification program for

interscholastic athletic programs. New

York state selection. Available at:

http://www.p12.nysed.gov/ciai/pe/

documents/scrivised2005.pdf2005.


82. Tucker R, Raftery M, and Verhagen E.

Injury risk and tackle ban in youth Rugby

Union: Reviewing the evidence and

searching for targeted, effective

interventions: A critical review. Br J Sports

Med 0: 1–6, 2016.

83. Vaeyens R, Lenoir M, Williams AM, and

Philippaerts RM. Talent identification and

development programmes in sport—

Current models and future directions.

Sports Med 38: 703–714, 2008.

84. van der Sluis A, Elferink-Gemser MT, Brink

MS, and Visscher C. Importance of peak

height velocity timing in terms of injuries in

talented soccer players. Int J Sports Med

36: 327–332, 2015.

85. Votteler A and Honer O. The relative age

effect in the German Football TID

Programme: Biases in motor performance

diagnostics and effects on single motor

abilities and skills in groups of selected

players. Eur J Sport Sci 14: 433–442, 2014.

86. World Rugby. Weight consdieration

guideline. Available at: http://playerwelfare.

worldrugby.org/?subsection564.


87. Wyatt H. Physical Development

Contributions to Biomechanical Injury

Risk in Female Gymnasts [thesis]:

Cardiff, UK: Cardiff Metropolitan

University, 2015.



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