1. Men have several erections at night A healthy man has between three and five erections each night, each lasting 25-35 minutes. It is common for men to wake up with an erection, the last of the night’s series. The reason for their occurrence is not completely clear, but studies indicate that nocturnal erections are closely related to the REM phase of sleep. That’s when dreaming happens most often. Regardless of the reason for their appearance, according to most doctors, night erections are a sign that everything is fine with a man’s health. 2. Penis length is not related to foot size The idea that penis size is proportional to shoe size is a myth according to a study published in the British Journal of Urology International. The researchers measured the penises of 104 British men, including teenagers and pensioners. The researchers found that the average size of the penis among the study participants was 13 cm, but found no relationship between its size and that of the foot. NEWS_MORE_BOX 3. The penis is not a muscle Contrary to popular belief, there are no muscles in the male genital organ. For this reason, he cannot move much when he is erect. The penis can be likened to a sponge that fills with blood during sexual arousal. Blood accumulates in two cylindrical chambers, causing the organ to swell and harden. The swelling blocks the veins that take blood away from it. When the erection wears off, blood flow to the chambers decreases, they narrow, allowing blood to drain through the veins.