This is a trace of my heart rate taken as I slept last night. The red line shows my heart rate in beats per minute. The time axis is time since start, but is close to clock time because I went to bed around midnight. When I realized a few months ago that I could do this I was fascinated by the potential of getting a very small glipse into something that takes up 1/3 of our time and is of immense importance. Sleep amazes me. Any departure from consciousness is amazing; from passing out, to sleep to death. Your conscious brain goes away, is unleashed somehow and the results are usually profound. But sleep is also routine. We cut our brains and bodies loose from our “selves” every night.
This particular trace is a good one. I started my monitor about 30 minutes before I hit the light. You can see that, immediately, my heart rate falls. The spike at 30 minutes is when I got up to close the blinds. Soon after, I was asleep and for the next hour my heart rate settled into slow, deep sleep. The stretch from 1:40 through 3:40 is the coolest. I think this is a natural rise out of stage 4 sleep up into REM and then a drop back down. You can “see” dreams happening around 2:50 and again after 3:00 (and throughout the night). Normally, my heart rate would fall to the upper 30s in beats per minute, but I’ve been running a lot this week, so my body has extra work to do at night to repair tissues. One sign of overtraining is a resting heart rate that stays high or higher than normal. I’m not over training, just normal fatigue. After 3:40 where I hit stage 4 sleep again (probably) there’s a subtle rise and then lots of dreaming until about 5:30. I always think that morning sleep is the best and here it is laid out in the data. A solid 50 minutes of very slow heart rate and dead calm. Then lots of tossing and turning into morning (I think this because the trace looses contact around then a couple of times).
This trend toward deepest sleep in the morning rings true to what I know about myself in the morning. The standard sleep cycle chart has the deepest sleep happening early in the night with a gradual transition to shallower cycles as the morning dawns. I, on the other hand, seem to gradually step down into deeper and deeper sleep reaching my deepest sleep in the morning when normal people are already waking up. I am NOT a morning person. Ask anyone who knows me and they will tell you that I stay up late and sleep late and I think this is why. My circadian rhythm wants me to be out cold at around 6 in the morning most mornings. The times I have to wake early to catch flights or what have you, I feel utterly broken. My brain is out repairing itself, it wants to be out and I’m making it do something else and put more wear on it. I start work at 10 and work until 6:30, this will always be so if I have any say in it.
Last night I got more sleep than I have in a long while. Last weekend was rough and this week I’ve been expressing a really bad habit of keeping myself awake with computer screens of one kind or another. As a result of the long sleep, I feel awesome today. Drank a spinache/blueberry/rice protein smoothie for breakfast outside on the sunny balcony of my funky motel room. Yeah, sleep! If you can find the time, be nice to your brain. (note that I will almost never take this advice)