Tag: ouraring

Posted on
by

A couple of weeks ago the New York Times linked to a new study on age-related declines in human movement. It’s an odd study, but not because of the result (which shows that children start moving less at age 6), because that seems entirely predictable to me, despite the general understanding previously having been that the decline started in adolescence.

Rather, what makes the study seem odd to me is the weird blind spot the researchers seem to have about when and how organisms (including humans) choose to move.

In the study itself the researchers make clear that they had considered the obvious presumption—that kids start moving less when they start going to school: “The overt explanation for this earlier decline could be the increased sitting times due to school.”

The  blind spot I’m talking about is presented in the next sentence, where they immediately qualified that:

However, time-specific analysis of [physical activity] has revealed that in addition to the increased [sedentary behavior] during school hours, there was also a distinct decline on weekends, out-of-school days, and during lunchtime.

Schwarzfischer P, Gruszfeld D, Stolarczyk A, et al. Physical Activity and Sedentary Behavior From 6 to 11 Years.Pediatrics. 2019;143(1):e20180994

What’s weird and horrifying is that they make that statement seemingly without it occurring to them that forcing children to sit still for hours on 5/7ths of the days of the week might affect their behavior on the other 2/7ths of the days.

Right off the top of my head I can think of four obvious reasons that would be true:

  1. The required behavior in school normalizes the behavior of extended sitting.
  2. Even a few weeks of enforced extended sitting will result in the kids becoming deconditioned aerobically, making physical activity more difficult and less appealing.
  3. Extended periods spent in any static posture—especially the static posture of sitting—will begin the process of reducing their range of motion (they’ll pretty quickly lose the ability to squat, for example), again making physical activity more difficult and less appealing.
  4. The addition of “physical education” to the kids’ daily schedule sets the pattern of replacing movement with exercise—a time-bound, regimented activity which attempts to pack the health benefits of a week’s worth of movement into just a few hours. (I’ve written about this before.)

Just one instance of this blind spot is bad enough, but it shows up again in a key reference. The researchers say that it is accepted that physical activity declines with age: “A natural and biologically determined decline of total [physical activity] throughout the life span seems likely.” They support that assertion with a couple of references, one of which looks specifically at movement in non-human animals.

Unfortunately that study (Ingram, D. K. Age-related decline in physical activity: generalization to nonhumans. Med. Sci. Sports Exerc., Vol. 32, No. 9, pp. 1623-1629, 2000, which is sadly behind a pay-wall.) has exactly the same blind spot: All the animals studied were captive animals. That study looked at how animal movement varies when an animal is moved from its “home cage” to some other cage. I can’t say I’m the least bit surprised the behavior of those captive animals closely resembles the behavior of children moved from home to school and back again.

I would be very interested in studies that included some free-range animals. (Which isn’t something I can do, but which seems at least possible now that accelerometers  are cheap.)

Of course school isn’t the only factor that inhibits children from moving more. The restrictions on self-directed play so well documented by Lenore Skenazy of Let Grow no doubt feed in as well.

So it would be great if there were studies of movement in free-range kids as well.

The final weird and horrifying thing isn’t anything new, but is something I hadn’t really been aware of before: The assumption that an age-related reduction in movement is “natural and biologically determined,” has led directly to public policies that normalize it:

This decline is also represented in recommendations from the World Health Organization (WHO): preschool-aged children should accumulate a minimum of 180 minutes per day of total [physical activity], children and adolescents (4–17 years old) at least 60 minutes per day, and adults only a minimum of 30 minutes per day in moderate-to-vigorous physical activity (MVPA).

To which I say, “Argh!”

I probably wouldn’t be so struck by this if I weren’t already tracking my own movement. (Cheap accelerometers again.)

For some time now I’ve been working to a goal of 105 minutes of movement per day, and over the last few weeks I’ve come pretty close, averaging just over 102 minutes of movement per day, according to Google Fit. (This number, based primarily on steps, somewhat underestimates my movement. In particular it gives me almost no credit for the time I spend teaching taiji, because although there’s plenty of movement, there’s not much stepping.)

The WHO recommendations make me strongly motivated to upgrade my goal for movement to 180 minutes per day.

Why should kids under 6 get all the fun?

(The image at the top is topical only in that it is is a photo from our afternoon walk yesterday.)

Posted on
by

For a couple of years now, I’ve been having some trouble sleeping. It’s not a constant problem, but it has become more frequent than the rare thing it used to be.

I think the problem is just a string of one-off instances of stress. During this period I had one older relative begin having cognitive difficulties and have to move to a facility that could provide additional care, my cat got sick and eventually died, had some personality clashes related to volunteer work I’m doing grow into a problem that eventually involved lawyers, and had another older relative began showing signs of cognitive difficulties.

Each of these resulted in a pattern where I’d fall asleep just fine, but then wake up in the middle of the night and start ruminating about the issue of the day and be unable to fall back to sleep for an hour or three.

In the past when I had problems of this sort they tended to be short-lived. I’d stress out about something for a night or two or three, but the issue would be resolved soon enough and I go back to sleeping fine.

Here the issues have stacked up, new ones following the old ones.  Further, some of them don’t go away. They linger on.

As I say, I think that’s what’s happening here. Ordinary life stresses have simply come at me a little too hard and a little too fast, with the result that my sleep has been impacted.

However, maybe that’s not all that’s going on. Maybe there’s more to it. I know there are some other issues. For example, if I don’t keep my carb intake down my nasal congestion returns, and that dramatically interferes with my sleep.

Given that I’m not sure what all might be wrong, I thought it might make sense to investigate further—gather some data, and see if I couldn’t find some patterns in my sleep problems. To that end, I bought an Oura ring, a tracking device along the lines of an Apple watch or a Fitbit, but with its focus specifically on gathering and analyzing data about sleep.

I’ve only had it for a week so far, and I’m really just getting started at looking for trends in the data. For example, three nights ago I slept poorly (awake for almost 2.5 hours of the almost 9 hours I was in bed).

One possible reason was a too-large meal too late in the day. (It was the Winfield Village holiday party.) One piece of data that suggests that possibility is that my body temperature was elevated by 0.3℃ during the night—perhaps because of increased metabolic activity digesting all that food.

Interestingly, I got more deep sleep than I had all week up to now, perhaps because I went for a long run the day before. (Deep sleep is where you get the physical recovery from things like heavy weight-lifting sessions and long runs. Maybe the first few nights had less deep sleep simply because I didn’t need more than that, because I hadn’t had the hard workouts that require deep sleep for recovery.)

Here’s the next night, where I spent less time awake and almost as much time in deep sleep:

My body temperature was still up, though, even without the big meal. We had turned the thermostat down one more degree, but that’s about as low as we want it, so last night I rearranged the covers, removing the down comforter, going with just the wool blanket. I don’t know if that was a key change, but I slept very well last night:

Not only were my quantities of total sleep and deep sleep good, some of the other metrics were good as well. My temperature deviation was -0.3℃, which suggests that maybe I’ve got the covers and thermostat thing balanced just about right. My resting heart rate was down to 47, which suggests that I’ve recovered completely from the long run I took three days ago.

My hope is that by paying attention to this sort of thing, I can gradually eliminate these sorts of problems affecting my sleep. Of course that will leave me with the stress-related problems, but I think I know how to handle those—fixing the ones that can be fixed, accepting the ones that can’t be fixed, and engaging in appropriate self-care to help myself handle the stress better. And, of course, get enough sleep.