According to Dr. Billy Goldberg, author of Why Do Men Fall Asleep After Sex?, There are several causes of a man fast asleep after sex. The main reason is that the hormoneoxytocin, prolactin, gamma amino butyric acid (GABA), and several other hormones that make it instantly fell asleep.
"In a man's body chemistry changes after orgasm. Release of prolactin, which is abiochemical substance made man's body becomes very tired," explained Dr. DavidMcKenzie, a sex therapist in Vancouver, Canada, as reported by MSN.
He explained that the force during sex and after climax spent muscle glycogen _produce energy that cause drowsiness.
"Because men have more muscle mass than women, they usually sleepy after sex," he concluded.
