title: Digit ratio (2D:4D) and physical fitness (Eurofit test battery) in school children.
abstract: BACKGROUND
  The relative lengths of the index finger to the ring finger (2D:4D) is sexually dimorphic and is thought to be a correlate of prenatal sex steroids (low 2D:4D=high prenatal testosterone and low prenatal oestrogen). In adults there have been reports that low 2D:4D is consistently associated with high sports performance.
  
  
  OBJECTIVE
  To investigate correlations between 2D:4D and fitness levels in children.
  
  
  METHODS
  Right 2D:4D and body size were measured, in addition to flexibility, speed, endurance and strength (Eurofit tests).
  
  
  METHODS
  922 boys and 835 girls (mean ages (years): 10.8 ± 1.01 and 10.07 ± 1.00 respectively).
  
  
  METHODS
  height, mass, BMI, triceps and subscapular skinfolds, 20 m shuttle run, sit and reach, standing broad jump, hand grip strength, 10 × 5m sprint, and the sit and reach test.
  
  
  RESULTS
  Boys significantly outperformed the girls in the 10 × 5m sprints, the 20 m shuttle run, standing broad jump, and hand grip strength. In boys but not girls, 2D:4D was significantly negatively correlated with scores in all these tests except the standing broad jump. In girls but not boys, 2D:4D was significantly positively correlated to stature, mass, BMI and waist circumference.
  
  
  CONCLUSIONS
  It is suggested that high prenatal testosterone and low prenatal oestrogen (low 2D:4D) is implicated in high sprinting speed, endurance and hand grip strength in boys. In girls low prenatal testosterone and high prenatal oestrogen is associated with large body size.
authors.affiliation: Sport & Exercise Sciences, Glyndwr University, Wrexham LL11 2AW, UK.
authors.forename: R
authors.initials: R
authors.lastname: Ranson
authors.affiliation: Applied Sports Technology Exercise and Medicine Centre (A-STEM), Swansea University, Swansea, UK; School of Sport Exercise and Health Sciences, University of Western Australia, Crawley, WA 6160, Australia.
authors.forename: G
authors.initials: G
authors.lastname: Stratton
authors.affiliation: Sport & Exercise Sciences, Glyndwr University, Wrexham LL11 2AW, UK. Electronic address: s.taylor@glyndwr.ac.uk.
authors.forename: S R
authors.initials: SR
authors.lastname: Taylor
mesh_terms: D002648:Child; D002657:Child Development; D004967:Estrogens / Q000378:metabolism; D005260:Female; D005385:Fingers / Q000033:anatomy & histology*; D006801:Humans; D008297:Male; D010809:Physical Fitness; D012727:Sex Characteristics; D013739:Testosterone / Q000378:metabolism
chemical_list: D004967:Estrogens; D013739:Testosterone
keywords: 2D:4D; Anthropometrics; Children's fitness; Eurofit; Testosterone