Concerns about riding-related impotency are not new - doctors have suspected this link since the 1970s - but it wasn't until Bicycle Magazine ran an article in August 1997 that this issue became more widely known.
The problem is mainly the saddle, though improvements in their design have been introduced since the mid-1990s when champion cyclist Lance Armstrong discovered he had testicular cancer. Our bodies are designed so when we are in a sedentary position the weight is distributed on two sit bones (ischial tuberosities) that are protected by muscle and fat. This area doesn't have any arteries or nerves so it's perfect for sitting on flat surfaces such as chairs. A bicycle saddle, on the other hand, is much narrower than a chair and tends to fit between these bones. It's this area, called the perineum, that has all the nerves (particularly the pudendal nerves) and arteries (cavernosal artery) leading to the penis and which are responsible for the blood flow that causes erections. While sitting on a chair doesn't cause any obstruction of blood flow, a narrow bicycle can reduce the flow by up to 66 per cent.
But the bad news doesn't stop there. Once crushed, these arteries don't always return to normal. Dr Irwin Goldstein, a renowned impotence researcher from Boston University, emphasises that any numbness after a long bike ride isn't part of the pain of training, but could lead to serious problems. And other studies have found this type of bicycle injury early in life could cause sexual dysfunction later. While the studies have focused mainly on men, researchers believe women are also prone to these types of bike-related injuries because of similarities in certain parts of the male and female anatomy.
Many of the studies on impotence problems in sport have compared cycling with swimming and long-distance running. While many cyclists reported erection problems and numbness, very few of the other athletes had these problems.
Another researcher, Dr Roger Minkow from California, estimates that 50 per cent of men who ride a bike for two to three hours continuously experience numbness or pain. Goldstein feels there is such a strong link between bike riding and sexual impotence that he recommends giving up cycling all together. However, not all specialists agree with him. Dr John McConnell, head of urology at the University of Texas, advises men who are worried about impotence to stop smoking and manage cholesterol levels first, in order to keep the arteries clear, before they give up bike riding.
Regardless of whether you believe the research, here are a few techniques that will encourage blood flow during long bike rides.