It's what's between your legs that counts.
“While seated on a bicycle, the external genital nerve and artery are directly compressed. It is possible that chronic compression of the female genital area may lead to compromised blood flow and nerve injury due to disruption of the blood-nerve barrier.”
...male cyclists can suffer from genital numbness and erectile dysfunction.
That explains the sour mean faces that Lady Cyclists have as they wobble down the road laden down by Greenpeace stickers and sensible shoes in their organic hemp bags. Apart from the short trip to the range at the Pub, laden down with the Lee Metford on my back, you won't catch me risking the old todger by mounting the iron horse. Funny how the anti-car fascists never point out that cycling ruins your tackle....
(Apologies to any readers who are offended by this story).