The General Public Now Understands That Puberty Provides a Game-Changing Advantage to Males. What About Younger Children?
Updated August 12, 2025
Here’s what the recent research shows: Even pre-puberty, males have substantial testosterone-based advantages, which begin before birth. In utero, male fetuses receive an infusion of testosterone that is later associated with young boys’ somewhat greater strength and somewhat greater propensity for aggression – the androgenic effects of testosterone. For example, fitness data from over 85,000 children in Australia showed that, compared to nine-year-old females, nine-year-old males were 9.8 percent faster in sprints (running) and 16.6 percent faster in the mile run. They could jump 9.5 percent farther, could complete 33.3 percent more pushups in 30 seconds, and had a 13.8 percent stronger grip.
Significant male advantage was also found in a study of Greek children pre-puberty. Compared with six-year-old females, six-year-old males completed 16.6 percent more shuttle runs in a given time and could jump almost ten percent farther from a standing position. Another Danish study showed six- and seven-year-old males had a higher aerobic capacity (VO2max) than girls in the same age group.
A 2022 analysis of American swimming records showed that boys’ records in the ten- and-unders (nine and ten-year-olds) average 0.57 seconds faster per 100 yards than girls’ records. Boys’ records jump to an average of 3.01 seconds faster per 100 yards for the 12-and-under group and more than 4.5 seconds faster per 100 yards between the ages of 13 and 18. Jerry Giordano, an attorney who conducted the analysis, concluded that “about two-thirds of the eventual male-female differential in the performance of top swimmers emerges by the age of 12.”
The pattern is even more dramatic in children competing in track. Every USA Track & Field age-group national championship record is better than the girls’ record. This is true beginning with the youngest competitive age group (eight-and-under), with the gap growing dramatically during and after puberty.
According to Greg Brown, professor of Exercise Science at the University of Nebraska at Kearney and a leading researcher on this topic, “Before puberty, boys tend to outperform girls of the same age in tests measuring muscular strength, muscular endurance, running speed, aerobic fitness, ball throwing, and kicking distance. Conversely, girls typically exhibit better performance in tests focused on flexibility. While physical fitness tests do not always accurately predict success in competitive sports, physical fitness is often a prerequisite for success in sports.”
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References
Atkinson, Mira A., et al, “Sex Differences in Track and Field Elite Youth,” Sport Rxiv, 2023.
Boys vs. Women: Male High School Athletes vs. Female Olympians
Brown, Gregory, “Are There Sex-Based Differences in Athletic Performance Before Puberty?” Reality’s Last Stand, Aug 31, 2023.
Brown, Gregory, “Concerning Male Physiological and Performance Advantages in Athletic Competition and the Effect of Testosterone Suppression on Male Athletic Advantage,” White Paper, December 14, 2021.
Brown, Gregory, “Males and Females Are Different and That Matters in Sports,” Women’s Liberation Front, October 2, 2024.
Brown, Greg, et. al., “Sex-based differences in track running distances of 100, 200, 400, 800, and 1500m in the 8 and under and 9–10-year-old age groups,” European Journal of Sport Science, February 5, 2024.
Brown, Gregory and Mary O’Connor, “Fatal Flaws In the IOC Sponsored Research Study on Transgender Athletes,” Reality’s Last Stand,” May 8, 2024.
Catley, Mark and Grant R. Tomkinson, “Normative health-related fitness values for children: analysis of 85347 test results on 9-17-year-old Australians since 1985,” British Journal of Sports Medicine, January 4, 2013.
Clark RV, Wald JA, Swerdloff RS, Wang C, Wu FCW, Bowers LD, Matsumoto AM 2019 “Large divergence in testosterone concentrations between men and women: Frame of reference for elite athletes in sex- specific competition in sports, a narrative review.” Clin Endocrinol (Oxf) 90:15-22.
Eiberg S, Hasselstrom H, Grønfeldt V, et al. “Maximum oxygen uptake and objectively measured physical activity in Danish children 6–7 years of age: the Copenhagen school child intervention study.” Br J Sports Med. 2005;39(10):725–30.
Falkner, Frank, et al., Human Growth, “Boys demonstrate, on the average, greater strength than girls at all ages. Sex differences throughout childhood are consistent, although small.” 1978, Page 286.
Giordano, Jerry, “The Boy-Girl Difference in Swimming Records,” Ricochet, June 25, 2022.
Hilton, Emma and Tommy Lundberg, “Transgender Women in The Female Category of Sport: Perspectives on Testosterone Suppression and Performance Advantage.” Sports Medicine. 2021;51: (PMID 33289906 and doi: 10.1007/s40279-020-01389-3). This research is one of the most cited ever in academic literature. It definitively establishes that no amount of testosterone reduction can make male competition in women’s categories fair or equal, even when the athlete has been on testosterone blockers for many years.
Hooven, Carole, T: The Story of Testosterone, the Hormone That Dominates and Divides Us. New York: Henry Holt, 2021.
Joyner, Michael, et. al, “Evidence on sex differences in sports performance,” Journal of Applied Physiology, 2025 Jan 1, 2025, 274-281.
Tambalis KD, Panagiotakos DB, Psarra G, et al. “Physical fitness normative values for 6–18-year-old Greek boys and girls, using the empirical distribution and the lambda, mu, and sigma statistical method.” European Journal of Sport Science. 2016;16(6):736–46.
Women’s Sports Policy Working Group, “Pre-Puberty, Children Show Marked Differences in Sport Performance,” July 20, 2025.
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For more about why it’s unfair for boys and men, regardless of gender identity, to compete against girls and women, see Our Position.