Male Participation in Female Sports

POSITION STATEMENT

American College of Pediatricians | December 2025

Male Participation in Female Sports

Genetics is the primary driver of sex differences, and these differences begin at fertilization when genes that are present on the X and Y chromosomes start to direct the development of the new individual.  Genes are expressed differently in males versus females, and so impact athletic abilities.  For example, there are over 3000 genes that are expressed differently in male and female skeletal muscles.

Testosterone plays important roles in regulating brain development, bone mass and shape, fat distribution, muscle mass, strength and density, heart size, lung capacity, and the production of red blood cells.  The result is a clear male advantage in all these systems even after adjusting for sex differences in height and weight.  Because testosterone is present during fetal life and early childhood, research shows differences between the athletic abilities of boys and girls even before puberty.

Male athletes consistently outperform females in speed, strength, endurance and power as demonstrated by world records that show males have a 10 – 30% advantage over females.  Estrogen use by males results in physiologic changes such as a redistribution of fat and reduction in muscle mass and hemoglobin levels,  but does not eliminate male athletic advantages.  Research shows that males on testosterone suppressants (anti-androgens and estrogen) have athletic performance that is lower than males not taking them, but their performance remains higher than that of women.

Therefore, it is not safe or fair to allow male participation in competitive female sports which require strength, power, endurance and speed. Sports, such as shooting and archery, which do not rely significantly on the aforementioned traits, may be safe and fair when carried out in a coed context even after puberty. This statement is not applicable for the rare individual with a disorder of sexual differentiation.

Corresponding ACPeds Referenced Paper:  Male Participation in Female Sports

Pertinent ACPeds Referenced Papers:  Sex is a Biological Trait of Significance

Fact Sheet:  Male Participation in Female Sports

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