Why sleep matters

Teenagers need 9-10 hours of sleep per night. Adults need 7-8 hours of sleep per night. That’s according to the Mayo Clinic. They also state that a lack of sleep increases the risk of illness after exposure to viruses. How much of an increased risk is it?

According to Cohen et al (2010), the risk is increased almost three-fold. Less than seven hours of sleep per night was associated with an increased risk of 2.94 times! Those whose sleep was less than 92% efficient (whatever that means) were a whopping 5.50 times more likely to get ill from virus exposure than those with sleep efficiencies above 98%.

Imagine there was a pill you could take each day that could reduce your risk of catching a cold by 66%, or another pill that could reduce the risk by 82%, would you take them? I suspect most people would!

Yet I usually go to bed at 10pm and awaken at 5pm, seven hours later. Usually I’ll have fallen asleep on the sofa long before 10pm anyway due to fatigue. Falling asleep on the sofa and then waking up to go to bed isn’t compatible with a ‘good night’s sleep‘. Cohen et al would say that is inefficient sleep.

We could naïvely say that if lack of sleep increases the risk by 294% and poor quality sleep increases the risk by 550% then both lack of sleep and poor quality of sleep combines those risks to 884%. Someone who is not getting enough sleep, and the sleep they do get is broken, is 8.84 times more likely to get ill when exposed to the same viruses as someone who gets sufficient good quality sleep each night. Again, we could naïvely say that means that someone with insufficient and broken sleep gets ill 8.84 times as often. Yikes! That means that sleep reduces the risk by a whopping 88.7%.

I am sure that isn’t exactly what the Cohen et al study said; I suspect there was considerable overlap in the samples of people with insufficient sleep and people with inefficient sleep. Nevertheless, the role of sleep in maintaining physical health is clear.

All this is to say: I’m ill again, for the second time this year. I thought it was hay fever from using the lycopodium powder with the Kundt’s tube yesterday, but now I’m not so sure.

So why do I get up so early? I am a morning shower person, I like to meditate in the morning, and I have to travel to get to work. It takes me at least 20 minutes when driving, 40 minutes when cycling (or up to an hour when the wind is in my face), or about 35 mins when getting the train unless I time it wrong and have to wait. I like to get into work for about 7am because it gives me a solid 1½ hours to get work done before my colleagues or students start interrupting me. Some teachers turn up at 08:30 and leave at 17:00, I turn up at 07:00 and leave at 15:35.

When I worked at a school in Greater Manchester, I would aim to get to work between 06:00 and 06:30. This was to avoid the horrendous traffic. I got into the routine of getting to work early, it works for me. I’ve no hope of marking in the evening, my brain turns off. I need to get marking done in the morning whenever I can.

So if I cannot wake up later, I’ll have to go to sleep earlier, right? Well that won’t work either. To get eight hours of sleep, I’d have to go to bed before 21:00. Given that I often fall asleep on the sofa, I might as well go to bed that early, but my wife usually works in the evenings and so the only time I get to see her is late in the evening or at weekends between her work (yup, she works weekends too). I wouldn’t want to sacrifice that time with her.

My situation is by no means unique. I have colleagues who I know work well past midnight each day marking students’ work, and commute over an hour each way each day. When teachers say they need more non-contact time to get work done, this is what we mean.

So, I’m ill yet again, but I’ll carry on working because my workload sharply increases when I am forced to take time off work (setting cover work, and then checking it has been effective afterwards, whilst catching up with the emails and meetings that were missed). COVID-19 was terrible in many many ways, but I miss being at home, exposed to far less sickness, having no commute, getting enough sleep.

During exam season, students will not want to get ill. Their best defence, it seems, is getting a good night’s sleep.