Physiological Perspectives - Maturation

Biological maturation is a critical factor in physiological responses to exercise and therefore to athletic performance. We know that, until puberty, boys and girls do not differ significantly in body size, composition or physiological response to exercise. There is huge individual variation, but it is not gender related. Athletically talented girls often outrun, jump or throw their male peers in the primary and early middle school years.

At puberty, which girls in general reach about two years earlier than boys, the body composition of girls comes under the influence of oestrogen, causing fat deposits to be laid down on hips and thighs and an increase in bone growth.

Significantly for the identification of athletic talent, not only is there huge individual variation in maturational rates in individual boys and girls, there is also huge inter-individual variability. In other words the many different components of maturation do not develop at the same rate in the same individual, meaning that scales of athletic performance related to maturational stage cannot be developed to predict adult ability with any degree of accuracy.

Late maturing boys and early maturing girls are disadvantaged in age group sport. Furthermore, extrinsic determinants are likely to be highly influential on performance at any point on the maturational curve.

To discuss objective selection criteria (performance marks) as a tool for the identification of talent seems an over simplification and a dangerous pathway without methodical assessment of the variables and strategies to improve opportunities for all.

Furthermore, wider social influences have obvious but under-researched effects on age related performance:-

These issues are also likely to be an influence on the retention of teenage participants in sport and therefore also on the social pattern of adult performance.

Fig 8 (Developmental curves for performance on vertical jump in five children over 5 years. Rowland and Cunningham. From Development Exercise Physiology, Thomas W. Rowland 96) emphasises the influence of individual maturational rates on athletic performance.

Sexual Maturation

Puberty, the succession of changes that occur in early adolescence culminating in fertility, is triggered by secretions of hormones from the hypothalamus, pituitary gland and ovaries. It is accompanied by the growth spurt and the development of secondary sexual characteristics (breast development, hip widening, increased body fat and body hair). Menarche (first period) occurs relatively late in the process, more than a year after the point of maximum growth rate during the adolescent spurt.

Although the process of sexual maturation for both sexes takes, on average, 4 years, there is huge individual variation, ranging from 18 month to 8 years. The greater average height of males is due to their much longer growth spurt phase. The changes that occur result in fully mature females being, on average: -

Anthropometric measurements at maturity differ substantially between the sexes. Women have narrower shoulders, broader hips, smaller chest diameters and tend to accumulate more fat in the hips and lower body. The cumulative effects of puberty can have an immediate, negative effect on a young girl’s athletic performance and the longer term effects are difficult or impossible to predict. The more precocious the talent the more obvious the effect of this can appear. Some girl athletes sail through puberty with hardly a hiccup, but for others the changes amount to a fundamental change of body type which demands a reassessment of potential or even of best event. Coaches cannot predict how young girls will be effected and therefore, as a sport, we must be very wary of either formal or informal talent identification processes aimed at girls under the age of 15, or even 17.

This is obviously a fundamental difference in athletics terms between the sexes, but one that, as a sport, we have failed to come to terms with fully. It can be hugely destructive of enjoyment and motivation, particularly if the girl is unprepared for the phenomenon or if it is unsympathetically handled by coach, club, parents and others. (See WSE dropout project)

Youngsters who show exceptional athletic ability at a very young age frequently excite very high, often unrealistic, expectations in those around them. Local media attention and that of family and friends have an impact on the girl, fanning hopes and aspirations for future Olympics at a time when such conclusions cannot realistically be made. These dreams are easily shattered by the performance effects of puberty and it can be equally hard for parents and coach to hide their disappointment. The effect on the girl’s self-esteem and self-perception can be damaging not only to her athletic career (complete drop-out from the sport is a big risk) but also to her as an individual and her relationships.

For the coach, retaining that athlete within the sport and maintaining self esteem and self confidence as a person, via patient support and explanation, needs to take precedence over athletic ambition. Social enjoyment within the club setting can be a crucial factor and is therefore athletically relevant to coaching. With this kind of background girls stand some chance of readjusting to the new realities, regaining equilibrium and appropriate athletic ambition.

It has been shown that menarche tends to come later in highly trained elite athletes in certain sports, but there is no scientific evidence to support the contention that intense training itself causes this delay. It seems more likely that female late maturers with a later menarche are more likely to be successful in sport. There is evidence that girls with tall, slim body shapes do in fact mature later. They also have more time to be socialised into sport and are more mature and therefore better equipped to deal with the social pressures which also contribute to drop-out.

There is a clear need for further, athletic specific study in this area so that coaches and team managers can be assisted to handle this complex process to the best advantage of the youngsters in their care.