Cycling can affect man's fertility

Cycling for at least five hours a week can affect a man’s fertility, according to researchers. Previous studies have shown that professional cyclists are likely to suffer lower sperm counts and poor semen quality, reports express.co.uk. Now it appears the risk is the same for casual cyclists too.

Men who cycle at least five hours a week have fewer and less active sperm than men who do not exercise at all, the study said. Researchers at Boston University surveyed 2,200 men attending fertility clinics who all agreed to provide a semen sample.

After adjustment for body weight, blood pressure, choice of underwear and other variables, they found that men who exercised regularly were no more likely to have problems with the quality or quantity of their sperm than men who never exercised. But when they looked at specific types of exercise, men who said they spent at least five hours a week cycling were twice as likely to have both a low sperm count and relatively poor sperm mobility.

This may be due to trauma or temperature rises in the scrotum, said study leader Lauren Wise.  "More studies are needed to replicate our findings before they can be considered causal," she said.