The statistics show that on average the body size of young female athletes from most sports is the same or greater than 50 per cent of the general population, they say. Female basketball, volleyball, and tennis players, swimmers and rowers all tend to be bigger than their non-sporting peers from the age of 10 onwards.
It is only really ballet dancers and gymnasts that are smaller, and who tend to sexually mature later than the general population. But say the authors, their size is appropriate for their sport, and it may be that girls of this stature self select for these sports, rather than the sport itself stunting growth. This is supported by studies showing that the parents of gymnasts tend to be shorter than average. A restricted diet is also likely to have an effect, say the authors.
Recent research has not been able to identify any link between training and body changes, manifest as thwarted or stunted growth and maturation, they write, even at the peak of the normal growth spurt.
Weight can be affected by training, particularly in gymnastics, ballet, figure skating and diving. But it is not easy to pinpoint weight reduction on training alone and exclude the effects of normal hormonal changes during adolescence.
Several studies have suggested that training delays the start of periods, but say the authors, most studies fail to take into account other factors that might influence this timing, and there is simply not enough evidence to blame training. Male gymnasts also tend to have shorter stature and reach sexual maturity later than their non-athletic peers, but no one blames intensive training for these trends, comment the authors.
'In general,' they conclude, 'the differences observed in stature are mainly the result of nature rather than nurture.' And they suggest that further research must be done before the blame can be pinned on training.
[Intensive training in elite young female athletes 2002;36:13-15]
Journal
British Journal of Sports Medicine