Is there any proven link between biking a lot and erection problems? Fertility problems?
A decade ago, a study (1) reviewed the evidence regarding the effect of cycling on impotence (due for example to pudendal nerve entrapment) and the effect of repeated scrotal temperature on spermatogenesis. While sparse evidence suggested a possible link, the author concluded that those results needed to be replicated in larger studies.
Some years later, several studies have indirectly investigated this:
- A study examined sperm quality among male partners (2261) of couples attending IVF (2)
Conclusion: in men who reported bicycling as their primary form of exercise, bicycling of ≥5 hours per week was associated with low sperm concentration and total motile sperm
- A cross sectional study of 10 cyclist (compared to 10 sedentary controls) (3)
Conclusion: compared to controls, cyclists had a lower proportion of spermatozoa with normal morphology. However, they did not report any significant difference in semen volume and sperm motility, viability and count.
- A study including 24 healthy non professional cyclists (4)
Conclusion: a 16-week low-to-intensive cycling training could possibly impact negatively on spermatozoa
Finally a larger and recent study (5) conducted in the UK in 2014 among 5284 male cyclist reported no associations between cycling volume erectyl dysfunction and infertility.
So to summarise, current evidence is controversial and larger studies are needed to investigate this potential association.
Southorn et al. Great balls of fire and the vicious cycle: A study of the effects of cycling on male fertility. The Journal of Family Planning and Reproductive Health Care. 2002: 28(4)
Wise LA, Cramer DW, Hornstein MD, Ashby RK, Missmer SA. Physical activity and semen quality among men attending an infertility clinic. Fertility and sterility. 2011;95(3):1025-1030. doi:10.1016/j.fertnstert.2010.11.006.
Gebreegziabher et al. Sperm Characteristics of Endurance Trained Cyclists. Int J Sports Med 2004; 25(4): 247-251
Maleki B. et al. Long-term Low-to-Intensive Cycling Training: Impact on Semen Parameters and Seminal Cytokines. Clin J Sport Med. 2015 Nov;25(6):535-40.
Hollingworth Milo et al. An Observational Study of Erectile Dysfunction, Infertility, and Prostate Cancer in Regular Cyclists: Cycling for Health UK Study. Journal of Men's Health. July 2014, 11(2): 75-79.