I have been tracking (quantifying) my sleeping solidly for about 3-5 years and its surprising to see the effect of the things like different alcohol drink, cheese, coffee, milk and chocolate. I also been to many events, with the last one being Cafe Sci: Myth and Science of Sleep. I generally track my dreams now, which is quite different from previously when I use to track them with a lot more detail.
Tracking sleep can seem a but of nonsense; I mean leaving your phone on your bed while you sleep or using a wristband device to collect data can seem poor for data collection. However with some calibration and a few months data, it becomes clear through the patterns whats good quality and bad quality sleep; oppose to the length of sleep. The key being the cycles of sleep… Light sleep into REM into deep sleep into light sleep and over again.
Here is me sleeping in a hotel for 5hrs 49mins after drinking cocktails in London during the week of Mozfest. You can see the alcohol puts me into deep sleep quickly but it takes a while for my body to get back into its normal sleep pattern. I also had a done a lot of walking that day.
This clearly shows although I had 7hrs 21mins of sleep when I woke up, I felt like crap. To be fair I had red wine, and was on cold meds to get rid of my long lingering cold. Once again I was in a hotel, this time in Sarajevo. No coffee this time.
This is from todays sleep, even with a few scoops of ice cream and coffee, I slept extremely well and woke up feeling pretty fresh and ready to take on the world.
Ultimately I would clearly say I have learned so much by looking at the patterns, especially over a longer period of time.