Many cyclists, over 60% according to Sommer et al., experience genital numbness and even ED (Erectile Dysfunction). ED, a persistent inability to achieve and/or maintain an appropriate erection for satisfactory sexual performance, may possibly be caused by an impeded blood flow and pressure on the penile nerves as a result of extended periods of time on the saddle. It has been shown that pudendal nerve (innervates the posterior aspect of the scrotum and the penile base) neuropraxia may lead to numbness and an altered sensation during ejaculation. ED has been associated with reduced NO production and/or its bioavailability to the corporeal smooth muscle. In addition, the increase in contractile factors and generation of superoxide anions have been shown to contribute to ED. Tiredness and fatigue can affect the ability to get or sustain an erection. This may sound strange but being tired can reduce sexual desire and libido to the extent that it is impossible to get or maintain an erection. Exhaustive endurance exercise, especially in overreaching/overtraining states can certainly be fatiguing to the athlete and may, therefore, possibly lead to ED.