Can bike seats harm your sex life? That's the conclusion of several studies, published recently in The Journal of Sexual Medicine, which blame ill-fitting saddles for erectile dysfunction in a small portion of male cyclists who log long hours in the saddle. Avoid injuries by choosing the right seat. Specialized's Alias ($100; specialized.com ), built for serious riders, features a V-shaped groove down the center to promote better circulation. It's light, feels cushy and comes in three sizes: retailers have a device that measures your undercarriage to ensure proper fit. Mellow bike-path riders can try the Easyseat ($29.95; hobsonseats.com ), a bizarre-looking noseless saddle that supports only the buttocks; it features two cushioned pads that tilt forward independently with each downward pedal stroke. Beyond seats, proper riding technique is crucial. Sit upright whenever possible and do like Lance: stand more, especially on hills.