The science backs her up: sex boosts the body’s oxytocin levels and decreases its production of the stress hormone cortisol, Dr Saralyn Mark from Yale School of Medicine told Women’s Health, making you feel more relaxed.
"Plus, having an orgasm releases a hormone called prolactin, which makes you feel relaxed and sleepy," says Morrison. "All of that leads up to a nice, drowsy state that's perfect for falling asleep."
The post-coital estrogen boost a woman experiences can also lead to deeper, more restful sleep, according to a study published in the Journal of Women’s Health.
In honour of World Sleep Day (yes, that’s a thing), Morrison also shares some equally steamy tips: “A magnesium bath soak can be a great way to relax and get ready for bed,” she says, “and eating primary nutrients that promote sleep, such as cherries, banana, walnuts, milk and herbal tea.”