Low Second-To-Fourth Digit Ratio Has High Explosive Power? A Prepubertal Study

Area of Science:

• Endocrinology
• Pediatric Sports Science
• Human Physiology

Background:

• The second-to-fourth digit ratio (2D:4D) is a proposed marker of prenatal androgen exposure.
• Previous research has hypothesized a link between lower 2D:4D ratios and enhanced physical fitness, including explosive power.
• Conflicting findings exist regarding the correlation between 2D:4D ratio and lower limb explosive power.

Purpose of the Study:

• To investigate the relationship between the 2D:4D ratio and lower limb explosive power in Taiwanese prepubertal children.
• To replicate previous findings and explore potential sex differences in this association.

Main Methods:

• A cohort of 541 Taiwanese children (257 girls, 284 boys, aged 9-10 years) participated.
• Lower limb explosive power was assessed using the standing long jump (SLJ) test.
• The 2D:4D ratio was calculated from measurements of the second and fourth fingers of the right hand.

Main Results:

• A significant negative correlation was observed between the 2D:4D ratio and SLJ distance in boys (r = -0.144, p = 0.015).
• This correlation remained significant in boys after controlling for age and BMI (r = -0.134, p = 0.024).
• No significant correlation was found between the 2D:4D ratio and SLJ performance in girls.

Conclusions:

• Prenatal testosterone exposure, as indicated by the 2D:4D ratio, may be negatively correlated with lower limb explosive power in prepubertal boys.
• The findings suggest a potential sex-specific relationship between prenatal androgen exposure and physical fitness traits.
• Further research is warranted to elucidate the mechanisms underlying these sex differences.