Age-related variation in anthropometric and maturity characteristics of soccer goalkeepers aged 11-14 years

The purpose of this study was to compare variation in body size and physique considering somatic maturity status of young sub-elite soccer goalkeepers within two competitive age-groups. The sample included 17 sub-elite male soccer goalkeepers in two competitive age-groups, 11-12 years (n=8) and 13-14 years (n=9) proceeding from three clubs in the midlands of Portugal. Height, weight, arm span, body mass index, bicristal/biacromial ratio, sitting height/height ratio and four skinfolds were measured. Somatotype of Carter & Heath was calculated. Somatic maturity was assessed using the maturity offset and percentage of predicted mature height (%PMH). To analyse differences between young soccer goalkeepers of contrasting age-groups, the Mann- Whitney U test was performed. In sequence, the 11-12 and 13-14 years old groups differed significantly in chronological age, maturity offset and %PMH (p <0.01). Estimates for age at peak height velocity, expected to occur, respectively at about 13.97 years of age (95% CI: 13.63-14.31) and 14.07 years (95% CI: 13.62-14.53) show that the older group already experienced this event in 0.15 years (95% CI: -0.33-0.63). For anthropometric characteristics differences were found for weight (p <0.05), height, arm span and sitting height (p <0.01), but not for the other variables. In conclusion, variation in body size associated with the age-group in young soccer goalkeepers is mostly related to growth and maturation and the use of somatic indicators can be a very practical and useful instrument for coaches.