According to Indian-origin researcher Vinod Nargund of St Bartholomew's and Homerton Hospitals in London, the problems to look out for include genital numbness, erection problems, skin irritations and soreness in the groin area.

He has pointed out that more than 60 per cent of male cyclists who have taken part in research studies have reported genital numbness.

"Numbness is common because the pressure of the saddle can impair the blood supply to this area and put pressure on the nerves in the penis. This can also affect a man's ability to get an erection.

"There is a greater incidence of numbness and erectile problems in men who cycle regularly and over longer training distances. That is why it is important to rest intermittently during prolonged and vigorous cycling," Nargund said.

Men who cycle a lot can also experience changes to their sperm function, because of the excessive heat generated in the pelvic area.

Regular cyclists can run a higher risk of testicular damage and impaired testicular function also. Mountain bikers run a particular risk as studies have shown that they exhibit higher levels of scrotal abnormalities than on-road cyclists.

"The bicycle saddle is in direct contact with the perineum and its underlying structures. It makes contact just behind the scrotum where the nerves and blood vessels enter the back of the scrotum and penis. This area is sensitive, with hair follicles and sweat and sebaceous glands, which are all good breeding grounds for infection. Abrasions, bruising and damaged hair follicles and are among the most traumatic cycling injuries. Sweating in this area can also cause soreness and skin problems," he said.