Digit ratios and motor and health-related fitness in pre-adolescent females. 
Background: Assessing different aspects of physical fitness in children whose abilities are undeveloped and their associations with second-to-fourth digit ratio (2D:4D) may better determine the potential athleticism of an individual.  Aim: The purpose of the study was to examine relationships between the digit ratios and selected motor and health-related fitness parameters in a large sample of pre-adolescent females.  Subjects and methods: Participants included 8-12 year old Iranian and Afghan girls.  The length of the left and right second and fourth digits was measured by scanning and computer-assisted image analysis.  Motor- and health-related fitness tests were evaluated.  Results: No significant correlations were noted between right 2D:4D ratio and physical fitness components.  Left 2D:4D and physical fitness components were not correlated, with the exception of handgrip strength (r = -0.193).  However, right and left second digit lengths were negatively correlated with predicted VO2max (p ≤ 0.01).  In addition, right-left 2D:4D was significantly negatively correlated with flexibility, and significantly positively correlated with height and body fat percentage.  Conclusion: In contrast to previous investigations, it seems that left 2D:4D is a predictor of strength, but not aerobic exercise.  It is suggested there may be a potential relationship between prenatal androgen exposure and high flexibility, low body fat percentage and the generation of muscular strength in pre-adolescent females.