Millions of people ride bicycles to stay in shape, but some studies show that riding could have a serious side effect for men.
"After six or so years of very aggressive riding, I experienced E-D, Erectile Dysfunction. It was very sudden," says Fred Denapoli patient.
"It's an official, medical, scientific, problem. "We believe that in and around five percent of men who ride bicycles will endure the problem," says Irwin Goldstein Editor in Chief of Journal of Sexual Medicine.
Dr. Goldstein says three recent studies, including one of his own, show the same thing. He studied people who were sitting on a table or sitting on a stationary bike, and he found many bike seats force the rider to lean forward, bearing all the weight on an artery where blood flow is stopped of slowed to that area. Some experienced bike riders say this is not a problem, but Dr. Goldstein says men who ride regularly and suffer sexual dysfunction, may want to look first at that bike seat as a possible reason.