Why Male and Female Athletes Do Not Belong in the Same Sport: A Scientific and Moral Case for Protecting Women’s Athletics

Let’s be clear from the start: this is not about hate. It’s about fairness, safety, and science. Biology isn’t bigotry, and defending the integrity of female athletics should not be controversial.

The scientific data is overwhelmingly clear. Men and women are physiologically different in ways that significantly impact athletic performance especially in sports that demand strength, speed, and power.

In 2017, more than 5,000 male athletes including teenagers ran 400-meter times faster than Olympic gold medalists Sanya Richards-Ross and Allyson Felix. These weren’t professional athletes some wouldn’t even qualify as top-tier male performers. Yet they easily outpaced the fastest women in the world.

Allowing biological males to compete against female athletes jeopardizes fairness. It replaces elite female performers with average or above-average male athletes. Girls and boys experience different changes throughout puberty. See this thread on X outlining those differences in strength, speed, power, and muscle in girls and boys.

Eight Biological and Physiological Differences in Athletic Performance

1. Genetic & Chromosomal Differences: Males (XY) have the SRY gene on the Y chromosome which leads to testosterone production and male development. Females (XX) lack the SRY gene and develop under the influence of estrogen and progesterone.
2. Hormonal Profiles: Men have elevated testosterone, resulting in more muscle, strength, and energy availability. Women have more fat storage and cycle-related energy variability.
3. Muscle Mass, Strength & Power: Men typically have ~40% muscle mass vs. women’s ~30–35%. Men are 30–50% stronger in upper body strength and have greater power due to fast-twitch fibers and neural drive.
4. Power Output: Teen boys show significant improvements in vertical jump and explosiveness due to testosterone. Teen girls show smaller gains unless trained.
5. Speed Development: Teen boys post-puberty sprint faster due to limb length and lean mass. Girls plateau unless they receive specific training.
6. Skeletal Structure & Biomechanics: Men have denser bones and stronger joints. Women’s biomechanics increase ACL injury risk and limit force output.
7. Cardiovascular & Respiratory Function: Men have larger hearts/lungs and higher VO₂ max, excelling in endurance sports.
8. Neurological & Metabolic Factors: Men recruit more muscle fibers for explosiveness and rely more on carbs; women are more efficient at fat metabolism but at risk for energy deficiency.

This is not just about stats—it’s about scholarships, safety, and self-worth. If we continue to allow biological males into women’s sports, we will rob female athletes of earned recognition, scholarship opportunities, and safety, while undermining Title IX progress.

Not speaking out is not neutral—it’s harmful. If you’re a female athlete, a coach, or someone who cares about truth, you must advocate for women’s sports.

One reminder of why I do this came while traveling in California. A softball mom recognized me from social media and I ended up leading a devotional for her daughter’s team. These girls are the reason I speak up.This isn’t about discrimination. It’s about fairness. This isn’t about exclusion. It’s about integrity. This isn’t about feelings. It’s about facts.

Women’s sports were created because of biological differences. Denying those differences erases women and robs girls of the chance to compete, thrive, and win on a level playing field.

Let’s stand for what’s right. Let’s follow the science. Let’s protect women’s sports.

Please see references to speed, power and strength in a X Thread HERE.

Notable sources:

Bale, P., Mayhew, J. L., Piper, F. C., Ball, T. E., & Willman, M. K. (1992). Biological and performance variables in relation to age in male and female adolescent athletes. The Journal of sports medicine and physical fitness, 32(2), 142–148.

Doré, E., Martin, R., Ratel, S., Duché, P., Bedu, M., & Van Praagh, E. (2005). Gender differences in peak muscle performance during growth. International journal of sports medicine, 26(4), 274–280. https://doi.org/10.1055/s-2004-821001

Handelsman D. J. (2017). Sex differences in athletic performance emerge coinciding with the onset of male puberty. Clinical endocrinology, 87(1), 68–72. https://doi.org/10.1111/cen.13350