If you find that you need to take a catnap after sex, you're not alone. There are actually several reasons why people feel tired after intimacy.
"One possibility is that you could just be physically exhausted, giving you a similar feeling of fatigue after doing some intense cardio. It's also possible that you're reacting to the change in chemicals that are released during and after an orgasm," Huizenga told Insider.
The neurochemicals that are released building up to and during an orgasm amp up arousal and excitement, he explained.
"Afterward, the profile of chemicals released changes abruptly. Men, more so than women, tend to get very sleepy, likely because they respond more to the morphine-like sedating properties of the endorphins," Huizenga said.