Time-tracking revelation: I don’t need 8 hours of sleep

I began tracking my time continuously in April 2015. It is now October 2018, which means that I have been tracking for three-and-a-half years.

When I mention this in talks, people sometimes ask what I’ve learned. I have a few standard stories I tell, about work hours, reading time, and time in the car.

But here’s another epiphany that is having a surprisingly big impact on my life: I don’t actually need 8 hours of sleep.

Before anyone thinks that I am suggesting skimping on sleep as a productivity tactic — no. Getting the amount of sleep your body needs is important for health and, frankly, getting stuff done. Sleep-deprived people rarely operate at their best.

But how much sleep does one’s body need? This is a different, and very personal question. The “8 hours” figure is so common that this is the number I have in mind for a good night. It is the number I am thinking about when planning my time. Time-tracking has revealed that this probably isn’t the right number, at least for me.

I am not sure why this is so revelatory. I learned very early in my time-tracking journey that I wasn’t, generally, sleeping 8 hours per day. I gravitated pretty strongly to somewhere between 7.3 and 7.4 hours. (7 hrs 18 minutes and 7 hrs 24 minutes in case anyone needs help with the math.) Over any long period of time — like 6 months — this is what my average would be.

At some point I discussed this with my husband — that this was my set point — and he mentioned another possibility: what if this is the minimum my body can get away with? It was possible that I should be getting more (like 8 hours) but if I dipped below 7.3/7.4 for more than a few weeks, that’s when the catch-up impulse would be triggered. I’d be exhausted, go to bed early, nap, whatever.

It’s certainly a theory. After all, for the first 2.5-3 years of my time-tracking, my youngest child was doing his best to make my sleep as disordered as possible. My logs show a lot of middle-of-the-night wake-ups, long after this “should” have stopped. There were bedtime battles (as one example, I recall a horrible night in August 2017 when he would not go to bed until 1:30 a.m. — that’s at more than 2.5 years old). I went through a lot of 4:30 a.m. wake-ups, necessitating naps somewhere in the day, or crashing early.

In the past few months this has gotten much, much better. I worry about jinxing myself but in general, the little guy is in bed by 8 p.m. On the nights I put him to bed, I can read him a story, get him in his bed, give him a kiss and he stays there. Most nights. Not all nights, but most. Even in May I couldn’t rely on that (on Instagram, there’s a selfie of me sitting outside his bedroom, trying to keep him in. We had child locks on the doors but he figured those out). He either sleeps until 7 a.m., or stays in his room until some time around then, looking at stories.

So, for the first time in a long, long time (minus a short window in early 2014) I am setting an alarm that I believe might actually be the thing waking me up.

I need to wake my eldest child up around 7:15 a.m. on week days for everyone to get to school on time. Sometimes I run around 6:15/6:30 in the morning if it’s going to be a busy day, but I’m mixed on that. If I’ll be working at home, I prefer a mid-afternoon run outside. If I want to shower, dress, and have my coffee before I wake up my 6th grader, I need to be up by 6:45 a.m. If I don’t care (and hey, I work from home…I just need to avoid surprise video chats!) then it’s really 7:10.

I turn off the older boys’ lights at 10:00 p.m. So there is a seemingly large window of time — at least 10:15 p.m. to 6:45 a.m. — during which sleep is an option (it definitely beats 10:15 p.m. – 4:30 a.m.!) I can sleep 8 hours. And as a proponent of good sleep hygiene, I have tried to take advantage of this window, doing my best to go to sleep around 10:30 or 11 at the very latest.

But when I do, I wake up before my alarm. Or I lie awake in bed (more rare — I tend to fall asleep relatively quickly).

It makes sense. Looking back on my logs I see that in 3.5 years I have had very, very few weeks featuring 56 hours or more of sleep. I wasn’t always around the little guy. Sometimes I was on vacation away from him. Sometimes I was in hotel rooms. Sometimes my husband was on baby-duty. If I needed 8 hours of sleep, I would have seen more of these weeks. Instead the handful (and I mean just a handful) of 56-hour weeks tended to happen on the heels of 46-hour weeks, nudging me back to the 7.3/7.4 hour average.

The reason this is revelatory is that it’s helped me think differently about sleep in general. Now that I can choose when I wake up (at least within a far more civilized window), I can choose when I go to bed. I can optimize for when I want my leisure. And I can relax a lot more about individual nights too.

In the past I would get slightly stressed about shorter nights. If I needed to wake up at 5:15 a.m. to get to the airport, I’d think it was a problem to go to bed at 10:15/10:30 — because I only had 6.75-7 hours to sleep. I now know that 6.75 is actually closer to 7.3 than 8 is. This night will be fine. Aiming for 7 on a normal weeknight is perfectly acceptable. If I sleep 7 hours for 4 nights and 8 for 3, I’m at 52 hours/week, which is above my set point.

This means that if I don’t want to be up at the crack of dawn — and honestly, most days there’s no reason* — I don’t need to go to bed at 10:30. I can stay up past 11. Heck, if I’m waking up at 6:45 a.m., my actual set-point bedtime would be 11:21-11:27 p.m. I can turn off the lights at 11:30, go to sleep at 11:45, and be fine.

For someone who spent the past three years trying to race into bed after the boys’ 10:00 p.m. lights out, this is very exciting. I can hang out with my husband! I can read another chapter in that book!

It might not seem like getting an extra 4.2-4.9 hours per week to play around with (realizing I can plan to sleep 51.3 – 51.8 vs. 56 hours) would be life-changing, but it kind of is.

How much sleep do you think you need? I think most people are between 6.5-8.5 hours/day averaged over the long term, though some people need more, and some people are short sleepers who require less (though these people are pretty rare).

* Yes, I wrote a book called What the Most Successful People Do Before Breakfast, but no, my natural tendency is not to wake up in the wee hours. Mornings are a great time for getting things done if you have other constraints on your time, like a full-time in-the-office job, or you’re home with little kids and trying to write a novel or start a business. I don’t have either of these constraints. Most week days I view 7-8:30 a.m. as family time as I get the kids up and ready and off to school. Then I start my work day.

Photo: Throwback Thursday shot of the little guy napping, back in the 4:30 a.m. wake-up days.

13 thoughts on “Time-tracking revelation: I don’t need 8 hours of sleep

  1. You seem to post on this a lot, and I’m wondering whether there is a back story. My number is 8.5, unfortunately. I often dream about all I could accomplish if I were to need less.

    1. @Omdg – I just find it such a fascinating topic! Partly because tracking data is often different from quick response survey data. Also, because sleep is something we all experience (frequently!) so it’s frequently top of mind. I understand the frustration with having a higher sleep need number — an hour makes a big difference in a very full life with a lot of responsibilities. I have certainly sometimes fantasized about being a Martha Stewart type (a short sleeper) but I don’t think it’s easily physically alterable, so no point really entertaining that fantasy much.

      1. Well in fairness to myself, I’m a good example of all that one can accomplish even though I need 8.5 hours. It certainly hasn’t held me back, I just need to be mindful about going to bed on time, about not driving home after a 28 hour call, and not letting what other people do dictate what I do to take care of myself.

  2. I love the topic sleep. Actually, I feel I still have not figured out how much sleep I need. I know I really don’t feel great if I get less than 6.5 hours, but I am not sure how much I need 8. It might also have to do with the quality of sleep and sleep cycles?

  3. I started tracking my time a few weeks ago. I love data so I’m really interested to see how much sleep I get (and how much time I spend doing other things). My instinct is that I’m about the same as you – averaging out to 7.5ish over time. My goal is to track for all of Q4 and then analyze!

  4. I could function indefinitely on 7 solid hours of sleep a night. Sometimes, I get less sleep than that, but I rarely get more. My typical sleep schedule is from 10:15 p.m. until 5:15 a.m. (with flexibility to sleep until 6:00 if I stay up late). I think there really is something to the ability to sleep uninterrupted. During the years when I had nursing babies, I could piece together 8 or more fragmented hours of sleep, but I was so tired all the time because it wasn’t restful sleep. These days, I rarely feel tired during the day, so 7 hours must be working for me.

  5. Hello, Laura, thanks for posting on this topic—very relevant. Since sleep factors so prominently in so many key issues of both physical and mental health, it’s a great question to ask onself—how much sleep do I need and am I getting enough? I’m good with about 7-7.5 hrs—too much leaves me feeling irritable and dissatisfied (as does too little!) It’s about self-care and knowing what I need to function best—also good to teach our children to think about their week. As always, thanks for sharing so generously—

  6. Random question Laura—are you doing nanowrimo this year? Always enjoy your progress updates and I’m toying with doing it this year.

  7. This article sounds like you are a kid who has just been granted a later bedtime! It’s so cute. It also made me realize I have no idea how much sleep I need. Some nights I work until 3 am and then am at work again at 9 am. But given the chance on weekends I can easily sleep 10 hours.
    After having kids I was pretty obsessed with sleep, and especially with when it was my turn to sleep in.

  8. Same. I think I do best on 7.5. Sometimes when I sleep 8.25+, I actually feel pretty groggy. I’m sure that’s just because of a sleep cycle issue, but it still affects my day. I’m going to start actually tracking my sleep quality soon, so that will be interesting (you should do this!). Expectations of sleep requirements do make a huge difference in overall attitude. I feel perfectly content going to sleep knowing I will get 7 hours, but start to stress when this dips below 6.5. And 30 extra minutes of leisure time makes a huge difference as well. One thing my husband and I disagree on is that he will prepare everything for the morning at night. Even though it’s more “organized” I’m not always inclined to do this, because it basically just shifts work I can do frantically in the morning (finishing touches on my lunch, packing up my bag, etc.) to the night (leisure/relaxation time), and there’s no net gain in time.

  9. Laura coincidentally I just read a ton of articles online about how sleeping more than 8 hours a night is associated with a host of health problems, including increased risk of stroke, depression, obesity, etc. So you might be on to something! Sleeping longer than 9 hours is even associated with MORE fatigue, not less. Shocker.

  10. Sleep is something I feel passionate about. I’ve always seemed to need more than most people around me. I definitely need more than eight hours. At one point, it was closer to ten hours. I think I’ve come to need a little less in the past couple years – eight and a half to nine would probably be ideal. I’ve discovered this during time off – after the first couple of days of reset, I settle into these natural blocks of time and feel rested and awake when I get that amount. Unfortunately, my normal work-day/life-day schedule doesn’t allow me to sleep that much so I live on a perpetual deficit.

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