title: Participation-related relative age effects in Masters swimming: a 6-year retrospective longitudinal analysis.
abstract: Medic and colleagues (Medic, Starkes, & Young, 2007) found that relatively younger cohorts of Masters athletes had higher participation rates and achieved higher performances compared with a relatively older cohort. Considering that Medic and colleagues' (2007) study was cross-sectional in nature, the purpose of this investigation was to employ a retrospective longitudinal study design to examine the participation rates of Masters swimmers as a function of an individual's constituent year within any 5-year age category over a period of 6 years. Using archived data from the 2003 to 2009 US Masters Short Course National Championships, swimmers' attendance was followed for a period of six consecutive years. Results indicated that a participation-related relative age effect was observed among swimmers who, over a period of 6 years, competed in either at least one championship (N = 2596; Cochran's Q₄ = 64.16, r(s) = -0.92, both P < 0.0001) or at least three championships (N = 441; Cochran's Q₄ = 47.51, r(s) = -0.91, both P < 0.0001). Overall, effect size analyses indicated that the odds of a Masters swimmer participating in the championship during the first constituent year of any 5-year age category was more than two times greater than the odds of that athlete participating during the fifth constituent year.
authors.affiliation: School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia. n.medic@ecu.edu.au
authors.forename: Nikola
authors.initials: N
authors.lastname: Medic
authors.forename: Bradley W
authors.initials: BW
authors.lastname: Young
authors.forename: Dragana
authors.initials: D
authors.lastname: Medic
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000502:physiology*; D054874:Athletic Performance / Q000502:physiology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013550:Swimming / Q000502:physiology*