On April 25, 2025, inside a Los Angeles film studio, excitement filled the air as if a major sporting event was about to unfold. The event: Sperm Racing. The concept was born from a conversation about sperm health between 17-year-old Eric Zhu—a startup entrepreneur—and a group of friends during a concert.
Zhu, who later co-founded and organized Sperm Racing, remarked, “Everyone talks about sperm in such a degenerate way…but if I could associate [sperm] as a biomarker in a competition or a sport…it was such a fascinating concept.”
Over the past four decades, studies report a sharp decline in sperm counts, linked to lifestyle changes (poor diet, obesity, smoking), environmental exposures, and biological factors such as swollen veins in the scrotum.1-3 Despite his limited biology background, Zhu saw an opportunity to reframe the conversation around male fertility.
As a former swimmer, Zhu drew parallels between training for athletic performance and optimizing sperm health. He remembered how his diet and flutter-kick drills helped improve his swimming. Why not apply that same logic to sperm and make it a sport?
With help from scientists, including then molecular biology student Jibraan Kadri at the University of Guelph, Zhu and a team of young entrepreneurs built a five-millimeter two-lane course microfluidic racetrack. Four contestants, including college students from rival Los Angeles schools, trained for weeks by cutting alcohol, exercising, and improving their diets.
In each lane, roughly 200 washed sperm cells swam upstream using rheotaxis toward the finish line. The race played out in real time on a big screen, enhanced by computer vision software that turned the microscopic action into a 3D experience.
While the event can raise awareness of lifestyle factors that can lead to altered semen quality, Ricardo Bertolla, a male infertility researcher at Wayne State University, remarked that looking at the fastest sperm is not a good proxy for understanding male fertility. He added that many other factors such as sperm count, morphology, acrosome integrity (enables sperm to penetrate the ovum), DNA fragmentation, and mitochondrial activity can underlie male fertility. “The main thing here is we need to normalize men looking at their fertility status early to get individual baselines.”
While the spectacle came and went, Zhu remarked that there are plans for an even bigger event. He hopes that sperm racing will inspire young men to take their health—and their sperm health—more seriously.
- Levine H, al. Hum Reprod Update. 2017;23(6):646-659.
- Skakkebæk NE, et al. Nat Rev Endocrinol. 2022;18(3):139-157.
- Agarwal A, et al. Asian J Androl. 2016;18(2):163-170.