title: Factors associated with the ability to estimate actual speeds in recreational alpine skiers.
abstract: OBJECTIVE
  To measure on-slope speeds of alpine skiers and to compare their ability to accurately estimate their actual speed with regard to measured speed, age, sex, skill level, helmet use, and risk-taking behavior.
  
  
  METHODS
  Skiing speeds of 416 adult skiers (62% men, 38% women) were measured with a radar speed gun. Skiers were interviewed about their age, sex, skiing ability, helmet use, and risk-taking behavior. Additionally, skiers had to estimate their measured speed as accurately as possible. The difference between estimated and measured speed was described as error of estimation (EE).
  
  
  RESULTS
  Mean measured speed (±SD) of all participants was 48.2 (±14.3) km/h. Pearson correlation coefficient between the actual speed and the estimated speed was 0.57 (P < .001) for all participants. Skiers underestimated their measured speed on average by 5.8 km/h or 8.1%. A multiple hierarchical linear regression analysis revealed that when skiing speed is increased by 1 km/h the EE significantly decreases by 0.5 km/h. Male sex, higher skill level, risky skiing behavior, and younger age groups showed a significantly better ability to estimate skiing speed, whereas ski helmet use did not.
  
  
  CONCLUSIONS
  Skiing speed, age, sex, skill level, and risk-taking behavior seem to influence the ability to estimate actual speeds in recreational alpine skiers.
authors.affiliation: Department of Sport Science, University of Innsbruck, Innsbruck, Austria. gerhardruedl@uibk.ac.at
authors.forename: Gerhard
authors.initials: G
authors.lastname: Ruedl
authors.forename: Friedrich
authors.initials: F
authors.lastname: Brunner
authors.forename: Tomas
authors.initials: T
authors.lastname: Woldrich
authors.forename: Martin
authors.initials: M
authors.lastname: Faulhaber
authors.forename: Martin
authors.initials: M
authors.lastname: Kopp
authors.forename: Werner
authors.initials: W
authors.lastname: Nachbauer
authors.forename: Martin
authors.initials: M
authors.lastname: Burtscher
mesh_terms: D000367:Age Factors; D054874:Athletic Performance; D005260:Female; D006260:Head Protective Devices / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D012309:Risk-Taking; D012737:Sex Factors; D012865:Skiing / Q000293:injuries / Q000523:psychology*; D013647:Task Performance and Analysis