For decades, it’s been used as a gentle dig at people who earnest, well-meaning, maybe a little over the top, and care deeply about the natural world. But here is what we now know with a fair degree of scientific certainty: those tree huggers are onto something.

Overall, every indicator that I have seen shows that sex can positively impact sleep by triggering the release of hormones like oxytocin and prolactin, which promote relaxation and sleepiness, and also by reducing levels of a primary stress hormone called cortisol.

What is sleep?  Sounds like a silly question, but in reality, it isn’t. While we know its crucial for health and cognitive function, we still don't fully understand why we sleep, the precise mechanisms of sleep, and the full extent of its impact on the brain and body.