March 23, 2012 -- Cycling is great exercise, but if the handlebars are too low, it might be more uncomfortable.
People who spend a lot of time on bicycles or in indoor cycling class often complain of genital numbness, and now a new study in women suggests that low handlebars may be at least partly to blame.
Low Handlebars, More Numbness
The study gauged genital sensation in a group of female cyclists. Women whose handlebars were lower than their bike seats experienced more pressure as they rode and had more genital numbness.
Placing the hands at the top of curved handlebars, instead of at the bottom of the handlebars, can reduce pressure on the genitals, earlier studies have shown.
"Riding in a more upright position takes pressure off the pelvic area and places it on the sit bones," says Sarah N. Partin, who led the new research while studying for her master's degree at Texas A&M’s School of Rural Public Health.
"People who enjoy riding might want to bring their handlebars up some," she says. "It may not look as cool or be the most aerodynamic way to ride, but it could help them avoid problems."
More Pressure on Perineum
The study included 41 women who rode their bikes at least 10 miles per week with their handlebars positioned lower than their seats.
Researchers recorded the way each woman set up her bicycle, and then the bikes were mounted on stationary trainers so that seat pressure could be measured while the women were riding.
Sensitivity was measured at different genital locations, including the clitoris, perineum, vagina, labia, and urethra.
The research, which appears in The Journal of Sexual Medicine, shows that positioning handlebars lower than the seat resulted in more pressure on the perineum -- the area between the opening of the vagina and the anus.
The more a cyclist leans forward while riding, the more pressure is placed on this area, says researcher Steven Schrader, PhD, of the National Institute for Occupational Safety and Health (NIOSH).
He says that when cyclists lean forward, they place up to 40% of their body weight on the nerves and blood vessels near the perineum.
"We are putting a significant percentage of our weight on an area that is not very well protected," Schrader says. "We are designed to sit on our butts, but that isn’t what happens when cyclists lean forward."
'No-Nose' Saddle May Help
In earlier research, Schrader found that male police cyclists who had problems with erectile dysfunction and numbness reported fewer genital issues when they used a special bike seat that did not have the traditional "nose" saddle.
The study findings led the NIOSH to recommend no-nose saddles for people whose jobs involve riding bicycles. That recommendation also holds for recreational riders who want to minimize pressure on their genitals, Schrader tells WebMD.
Cycling endurance coach Gale Bernhardt, who has coached triathlon and cycling teams in two Olympics, says genital numbness is a far less common complaint than saddle sores and other issues among the women she trains.
Bernhardt is skeptical that elite cyclists will alter their riding styles or change their bike saddles based on the research.
"There is a lot of history in cycling and it is a hard group to change," she says.