The Key Metric No One Talks About With Sleep
And it makes a huge difference to waking up feeling rested
If you’ve read any of my work when it comes to health and athletic performance, you’ve probably cottoned on to the fact that I’m a bit of a metrics junkie. I’m not someone who is obsessed with metrics just for the sake of it though — I love metrics because they show me trends and patterns, which I can then experiment with to get better results.
Sleep is something I’ve been collecting a lot of data on over the past 9 months thanks to my Whoop tracker. So much of what I thought I knew was barely scratching the surface. And in the last couple of weeks, I’ve realised that even with all the mainstream health advice on sleep — how to sleep more, how to sleep better, how much sleep to get, no one has talked about what I think might be the most important part of a good night sleep.
REM and Slow Wave Sleep
REM (rapid eye movement, ie dreaming) sleep gets all the buzz and it’s totally important. The thing is, I’ve found that I always get plenty of REM sleep, it’s a non-issue. I usually get a lot of slow wave sleep (the cycle where you physically recover) as well. Yet sometimes I still wake up feeling tired and struggling. So what gives?
