2D:4D Ratio as a Predictor for Swimming Learning- A Pilot Study

Abstract

Introduction: Competitive swimming is one of the popular sports, where physical conditioning and skill have a large contribution in achieving high-level performances. In males, the second to fourth digit ratio (2D:4D) have lower values than females but the mean digit ratio remains the same with age. This ratio is considered to be a biomarker of the balance between Foetal Testosterone (FT) and Foetal Oestrogen in a nearly embryonic stage. Aim: To determine the correlation of 2D:4D ratio in swimming beginners. Materials and Methods: This cross-sectional pilot study was conducted in the swimming pool facility of Banaras Hindu University Varanasi, Uttar Pradesh, India from March 2019 to June 2019. A total of 118 (59 females and 59 males), swimming beginners participants having age between 18 to 27 years were selected and cross-sectional samples were taken for the study. Participants passed all the stages of swimming learning under a well-trained coach for six weeks. In the last week of swimming learning, final performance assessment tests were conducted. For which six minutes was given to each participant and the total distance covered during swimming was measured in meters. Body Mass Index (BMI) was calculated from measured height and weight. The left and right 2D:4D ratio, height and length of participants were recorded and analysed for correlation. The collected data were analysed using a Statistical Package for the Social Sciences (SPSS),16.0 version. Results: A total of 118 participants, 59 males and 59 females, with mean age of the male participants was 21.37±3.52 years and the mean age of the female participants was 20.64±2.63 years. The mean 2D:4D ratio of both right and left hand digits in both sexes was <1. In males, the right hand 2D:4D ratio was negatively correlated (r=-0.444) with swimming learning performance and it was found significant (p-value=0.004) but the left hand 2D:4D ratio was negatively correlated (r=-0.176) which was not significant with swimming learning performance. In female's right hand, the 2D:4D ratio and BMI were negatively correlated which was not significant with swimming learning performance (r=-0.095, r=-0.018, respectively). Conclusion: The study shows a significant 2D:4D ratio correlation with swimming learning performance in males right hand. So, 2D:4D ratios can be used as reliable criteria as a predictor of swimming learning and swimmer's competitive performance however, it needs further extensive study

Keywords

• endurance
• foetal oestrogen
• foetal testosterone
• muscle strength