The impact of maturity differences

We humans grow and mature very differently from childhood through adolescence to adulthood. The biggest differences arise in the pubertal years, as some adolescents progress relatively fast through puberty, whereas others progress much slower. This creates large maturity gaps between adolescents, even though they are the same age. This means that young athletes on the same sports team have very different preconditions for competing and developing in their sport. Studies show that the maturational differences influence team selection, physical performance, and training optimisation.

Team selection

One important area where maturity status impacts sports, is when athletes are either rejected or accepted into a team or academy. A study measuring maturity on 158 elite youth football players in France, showed a distribution of 62% being average maturers, 16% late, and 22% early.1 Another study, measuring 111 Portuguese and Spanish elite and regional youth players, had results of 57% average maturers, 8% late, and 35% early.2 A third study of 246 elite and local youth players from Portugal, Spain, Belgium, Italy, and Mexico, revealed 43% average maturers, 13% late, and 44% early.3

Study Early maturers Average maturers Late maturers
French elite players 22% 62% 16%
Portuguese & Spanish elite and regional level players 35% 57% 8%
PT, ES, BE, IT, MX elite and local level players 44% 43% 13%

It should be noted that the distribution of maturational status naturally will differ among groups of players, but also due to different methods of measuring and calculating maturational status. Despite these differences, the pattern in these studies suggests that there is a larger proportion of early maturers, meaning adolescents going faster through puberty, than late maturers on youth football teams. This is problematic, since maturational status is not a permanent condition. Late maturers will eventually catch up and maturity differences will even out. However, when late maturers are rejected early, even though they might have future potential, sports teams miss an opportunity to strengthen their own roster.

Physical performance

Another aspect affected by maturational status is physical performance. A study of a total 490 Belgian youth football players revealed significant differences in physical performance according to maturational status. There were notable differences in test results of strength, power, and flexibility among U14 and U15 players, and for sprint speed and cardiorespiratory endurance among U15 and U16 players.4 Another study of 78 Belgian youth football players on international level showed that early maturers outperformed late maturers on almost all fitness tests. The tests with significantly different results were handgrip strength, standing broad jump, countermovement jump, sprint 10 meters, sprint 20 meters, and sprint 30 meters.5

The maturational impact on physical capacity is bound to also affect performance in training and matches, which is problematic if coaches do not adjust for this in their selection and assessment of players. At the same time, physical trainers, whose mission is to develop the athletic capacity of players, will deduce a wrong impression of players, their performance, and development if not including maturational differences in their assessment and calculations.

Training optimisation

Several researchers have pointed out the importance of including growth and maturity assessment in the development of youth athletes. This includes an increased focus on developing muscle size after athletes have reached a point of maximum growth (peak height velocity), meaning at a relatively advanced maturational stage. At this point, testosterone and growth hormone levels are rising. It is also recommended that maturational status is considered when training other physiological attributes such as power, speed, and endurance. These attributes are suggested to be trainable right from early childhood to adulthood, but change with in importance and what results should be pursued in terms of training. Early and late maturers should therefore be on individual training and development programs, as they will benefit from different focus areas at different times.6 Conversely, if all athletes are on the same training program throughout their childhood and adolescence, based on chronological age, it will be disadvantageous to their development. Early maturers can miss out on advanced training and physical gains even though they would be ready, and late maturers can be enrolled in training that might not be beneficial yet, relative to spending time on increasing sports specific skills.

References

(1) Carling C, Gall FL, Malina RM. Body size, skeletal maturity, and functional characteristics of elite academy soccer players on entry between 1992 and 2003. Journal of Sports Sciences 2012 Nov;30(15):1683-93.

(2) Roche AF, Chumlea CW, Thissen D. Assessing the skeletal maturity of hand-wrist: Fels method. American Journal of Orthodontics & Dentofacial Orthopedics 1988 Nov;95(5): 449.

(3) Malina RM. Skeletal age and age verification in youth sport. Sports Medicine 2011 Nov;41(11): 925-47

(4) Vaeyens R, Malina RM, Janssens M, Van Renterghem B, Bourgois J, Vrijens J, Philippaerts RM. A multidisciplinary selection model for youth soccer: the Ghent Youth Soccer Project. British Journal of Sports Medicine 2006 Sep;40: 928-34.

(5) Vandendriessche JB, Vaeyens R, Vandorpe B, Lenoir M, Lefevre J, Philippaerts RM. Biological maturation, morphology, fitness, and motor coordination as part of a selection strategy in the search for international youth soccer players (age 15–16 years). Journal of Sports Sciences 2012 Nov;30(15): 1695-1703.

(6) Lloyd RS, Oliver JL. The Youth Physical Development Model: A New Approach to Long-Term Athletic Development. Strength and Conditioning Journal 2012 June;34(3): 61-72.