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Biobanding: A New Paradigm for Youth Sports and Training

2018; American Academy of Pediatrics; Volume: 142; Issue: 5 Linguagem: Inglês

10.1542/peds.2018-0423

1098-4275

Alan D. Rogol, Sean P. Cumming, Robert M. Malina,

Cardiovascular Effects of Exercise

Sports programs are an important activity for children and adolescents. They provide opportunities for regular engagement in physical activity, the development of motor skills, teaching values and life skills, and enhanced physical and psychological health. The benefits of sports participation are not, however, automatic. Negative experiences can result in a range of harmful outcomes, including injury; increased risk of eating disorders, and violence and aggression, including sexual abuse; poor sportsmanship; perceptions of low competence; and burnout. Pediatricians are often the medical professionals who know their patients best and are thus well placed to advise on the potential benefits and risks associated with sports participation.The significance of individual differences in biological maturation on children's involvement in sports and physical activity is well documented. Maturity-associated variation in size, strength, and power plays a significant role in the popular sports, such as soccer, American football, baseball, and ice hockey, among others. Success in these sports tends to favor boys who mature early, as documented many years ago in a survey of participants in the Little League World Series.1 Corresponding trends among female youth participants tend to favor girls who mature later in distance running, gymnastics, ballet, figure skating, and diving. Girls who mature in advance of their peers are more likely to drop out of sports and be less active at an earlier age, although they may more likely be represented in sports that demand greater size, strength, and power, such as tennis.A recent effort to address individual differences in biological maturation among participants in youth sports is labeled "biobanding."2 In biobanding, attempts are made to group youth athletes within a specific chronological age range on the basis of maturity status in an effort to reduce maturity-related mismatches in size, strength, power, etc. In biobanding, a noninvasive indicator of maturity status is used (the percentage of predicted height attained at the time of observation to delineate categories or "bands" of youth who are reasonably similar in maturity status). Given 2 youngsters of the same chronological age, the one closer to adult height is more mature.2Concern for individual differences in biological maturation has long historical roots. It was expressed >100 years ago in the context of the readiness of boys for the workforce when Crampton3 proposed the label "physiological age" on the basis of pubic hair development, with prepubescent representing the lack of pubic hair, pubescent representing rapid growth and pigmentation of pubic hair, and postpubescent representing the appearance of the kink or twist in pubic hair. In the context of the widely used stages described by Tanner,4 Crampton's3 pubescent stage would include stage 2 and perhaps stage 3, whereas the postpubescent stage would include stages 4 and 5 of pubic hair development, which also include the distribution of pubic hair. At approximately the same time, Rotch5 proposed the use of hand-wrist radiographs to determine "anatomical age" and suggested that it be applied in school, child labor, and athletics.The concept of matching youth athletes on the basis of growth- and/or maturity-based characteristics was mentioned by Krogman1 and is currently applied in a number of sports.6 In combat sports, youth are grouped on the basis of age- and weight-based criteria for the purpose of optimizing safety and equity of competition. Similar practices can be seen in youth rugby and American football in which particular teams and/or positions are restricted to youth who fall in line with specific age- and weight-based criteria. The New York State Public High School Athletic Association also proposed a systematic procedure in the early 1980s for evaluating the biological and behavioral readiness of seventh and eighth grade boys to "play up," that is, participate in interscholastic sports.7 Note that in many small communities, eighth grade boys are often called on to play with the high school football team.Biobanding is in many ways a recent iteration of the maturity-matching concept. It is a process whereby youth athletes are grouped on the basis of maturational rather than age-based criteria. It has implications for competition, talent identification, and training and is most relevant during puberty (age 9–15 years in girls and age 10–16 years in boys), when maturity-associated differences in size, function, and physiologic adaptation are greatest.Although the process of biobanding may appear complicated, it is actually simple and easy to apply. By using the percentage of predicted adult stature attained at the time of observation as the indicator of maturity status, groups or bands of youth who are similar in maturity status are defined. For example, maturity bands based on the percentage of predicted adult stature among 151 youth soccer players 11 to 14 years of age are summarized in Table 1. The influence of banding on the maturity and size of the players is obvious. The band spanning 85% to 89.9% has been applied in several soccer competitions for youth 11 to 14 years of age in an effort to reduce maturity-associated mismatches in size and athleticism.8 Similarly, a coach running a conditioning session that is designed to benefit youth who are prepubertal or early pubertal might limit the session to boys who are <85% of the predicted adult stature.Biobanding does not preclude the consideration of psychological and/or technical development and should be considered as an adjunct to, rather than a replacement for, age-group competition. Age-groups have many benefits and are ideal for matching players on the basis of experience, training, and cognitive social and motor development, all of which are more closely aligned with chronological rather than biological age.The practice of biobanding for competition recently has been trialed by the English Premier League with several apparent benefits. When competing against and playing with physically matched, yet older and more experienced, players, boys who mature early are exposed to a greater level of challenge and can no longer rely on their physical dominance. To succeed, they have to use their technical, tactical, and psychological skills and adjust to a style of play that is more advanced and played at a faster speed. Boys who mature early also benefit from being mentored by, and learning from, the older peers. Boys who mature late describe the experience of playing down as less physically demanding and technically less challenging. They do, however, benefit from having more opportunities to use and demonstrate their technical, tactical, and physical competencies and adopt positions of leadership.Biobanding strategies also are increasingly being applied in the design and provision of developmentally appropriate training programs for youth. In the principle of synergistic adaptation, training programs (allowing for technical competence) are more effective when they expose children to stimuli that complement their maturity status. Before puberty, optimal gains in strength, speed, and power are best achieved through neural adaptation. However, maximal gains during and after puberty are more likely to result from a combination of neural and structural adaptations.In summary, biobanding, as currently applied with a noninvasive indicator of biological maturity status, has been well received in the youth soccer community in the United Kingdom. The protocol, however, requires further systematic study of potential benefits and risks and applications in other youth sports.