title: Performance development in adolescent track and field athletes according to age, sex and sport discipline.
abstract: BACKGROUND
  Sex-specific differences that arise during puberty have a pronounced effect on the training process. However, the consequences this should have for goal-setting, planning and implementation of training for boys and girls of different ages remains poorly understood. The aim of this study was to quantify performance developments in athletic running and jumping disciplines in the age range 11-18 and identify progression differences as a function of age, discipline and sex.
  
  
  METHODS
  The 100 all-time best Norwegian male and female 60-m, 800-m, long jump and high jump athletes in each age category from 11 to 18 years were analysed using mixed models with random intercept according to athlete.
  
  
  RESULTS
  Male and female athletes perform almost equally in running and jumping events up to the age of 12. Beyond this age, males outperform females. Relative annual performance development in females gradually decreases throughout the analyzed age period. In males, annual relative performance development accelerates up to the age of 13 (for running events) or 14 (for jumping events) and then gradually declines when approaching 18 years of age. The relative improvement from age 11 to 18 was twice as high in jumping events compared to running events. For all of the analyzed disciplines, overall improvement rates were >50% higher for males than for females. The performance sex difference evolves from < 5% to 10-18% in all the analyzed disciplines from age 11 to 18 yr.
  
  
  CONCLUSIONS
  To the authors' knowledge, this is the first study to present absolute and relative annual performance developments in running and jumping events for competitive athletes from early to late adolescence. These results allow coaches and athletes to set realistic goals and prescribe conditioning programs that take into account sex-specific differences in the rate of performance development at different stages of maturation.
authors.affiliation: Norwegian Olympic Federation, Oslo, Norway.
authors.forename: Espen
authors.initials: E
authors.lastname: Tønnessen
authors.affiliation: School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom.
authors.forename: Ida Siobhan
authors.initials: IS
authors.lastname: Svendsen
authors.affiliation: Diakonhjemmet, Oslo, Norway.
authors.forename: Inge Christoffer
authors.initials: IC
authors.lastname: Olsen
authors.affiliation: University of Life Sciences, Ås, Norway.
authors.forename: Atle
authors.initials: A
authors.lastname: Guttormsen
authors.affiliation: Norwegian Olympic Federation, Oslo, Norway.
authors.forename: Thomas
authors.initials: T
authors.lastname: Haugen
mesh_terms: D000293:Adolescent; D000367:Age Factors; D056352:Athletes; D054874:Athletic Performance; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D009043:Motor Activity; D012727:Sex Characteristics; D012744:Sex Ratio; D014142:Track and Field