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Physical activity definitely makes a difference, but in my experience it will never cause me to sleep like my kids. That ship has sailed. I was very active last year, and had many days of 30k steps, sometimes although rarely 40k steps and I can't say I ever experienced falling a sleep and sleeping 8h rock solid. Maybe once.

edit: just checked, I did a 120km bike ride this year and the next night I slept for around 6h.

Long bouts of cardio nearly always interfere with my sleep. But I don’t think that’s abnormal; the body should be raising cortisol in response to energy demands.

Try weight training in the morning. I’m someone that doesn’t usually nap… but after starting weight training I find myself needing a nap in the afternoon, and it is much easier to fall asleep.

I do early morning weight training two to three times a week. When I get a good workout I noticed the sleepiness in the afternoon too, but I still do not sleep like my kids. To be clear, I don't have insomnia or a very difficult sleep, but the article is in general about sleeping less as you age. Leading a healthy lifestyle will definitely help get a better sleep, but now being around 40 years old, I just don't sleep like when I was a child, teenager or even in my late twenties. I don't need an alarm anymore for instance, I'll just wake up at 6am 6:30 no matter what I do.

My anecdotal experience agrees with this. Long/intense cardio doesn't improve my sleep but weight training seems to. Occasionally I have to struggle to stay awake to keep my schedule, which is marvelous compared to struggling to fall asleep!

> I did a 120km bike ride this year and the next night I slept for around 6h.

Intensive or prolonged exercise (especially close to bedtime) can actually interfere with sleep. I never sleep very well the night after 10k runs or 60km+ rides. There is a sweet spot (for sleep quality) between zero exercise and too much exercise.

Sleep quality would be a better metric than duration.

HRV is generally the metric used. You can measure that with a cheap chest monitor, or get a fitness watch that tracks it continuously throughout the day and night.

Good HRV levels are highly correlated to activity level, so your base hypothesis still makes sense.

Good point.

Is there a standardized way to measure sleep quality? Or are the numbers one measures only compareable as long as one uses the same device?

I would be interested in suggestions which watches measure the HRV / Sleep quality reliably and display the data on screen. Or let me get it from a Linux laptop. I hate having to install an app to get the info off the watch.

HRV is indeed a good proxy metric for sleep quality, and I can really recommend Garmin watches for measuring it. Even the cheap models track the "Stress" metric 24/7 (which is HRV under the hood). More expensive ones have pulse ox monitoring and a full blown sleep analyzer that provides sleep stage breakfown and a compound sleep quality score. All from just being worn on the wrist normally through the night.

However, HRV is not the whole story about sleep quality. If you develop sleep apnea, for example, your HRV will not react very much, though your sleep quality will suffer. There is no substitute for sleep study to detect such issues.

HRV is indeed a good proxy metric for sleep quality, and I can really recommend Garmin watches for measuring it

I'm a little skeptical about my Garmin's ability to accurately measure sleep quality.

Sometimes I wake up refreshed and felt like I slept very well, only to have my Garmin tell me that I had poor sleep quality (usually because of too little REM sleep), other times I've had a bad night of sleeping (like the dog needed to go out several times) and I wake up tired, and my watch congratulates me on good sleep quality.

I wonder if one of the sleep monitors that uses a pad on the mattress would be more accurate.

Sleep apnea isn't really detected by HRV no bit pulse ox is a pretty good indicator.

My understanding is that different devices measure HRV with different techniques, so they're not necessarily comparable. I've heard Apple Watch is especially bad at measuring HRV, while Garmin and Whoop are good.

One performance and health coach I follow recommends the Polar H10 chest strap to take a measurement every morning.

https://twitter.com/Alan_Couzens/status/1723334537235607989

https://twitter.com/Alan_Couzens/status/1473672665541984259

There's also not an absolute number or threshold that's good or bad. Generally higher is better, but what really matters are the fluctuations from a personalized baseline.

Is "take a measurement every morning" about sleep quality or about something else?

Is it even possible to sleep with the H10 strap?

Taking a measurement at the same time every morning helps to establish a consistent baseline so that you can detect changes from day to day. But the latest generation of smart watches can track HRV continuously throughout the day, so if you have one of those then taking specific measurements is less useful.

Yes, I find I sleep better after some proper exercise during the day. But when I was working I worked from home every work day, with only a tour round the block at lunchtime. I did much less exercise but slept like a baby. Not so now.

What’s the full sleep data, or at least the variance? 31 may be large enough. And if it’s not, getting more by the end of the year may not make a big difference. Power only increases at the square root of the sample size.

End of next year. So in theory I could 10x the number of data points.

But its one of the more annoying experiments to let a coin decide if you have to take another walk :) So I'm not sure how often I will do that. I'm pretty convinced already that walking more is a good thing.

I'm in a hurry right now, but I will probably write a full blog post about the steps-sleep relationship with p values and everything some time next year.

Makes sense. Also, while overfed idle wealthy people faceplant in CPAP machines, older people in traditional cultures with healthy physical activity and consumption levels continue to live long regardless. For example, the Hunza. Experimental results suggest this is because of both their activity levels and a reduced caloric intake of a low protein, plant based diet high in complex carbohydrates. But what would a continuous culture of longevity know?

I've never heard of the Hunza and kind of suspected that these "older people in traditional cultures" sounds too good to be true, and sure enough:

> A widely repeated claim of remarkable longevity of the Hunza people has been refuted as a longevity myth, citing a life expectancy of 53 years for men and 52 for women, although with a high standard deviation.

Like all modern claims, there's probably a kernel of truth. The "standard deviation" probably masks it. As with the whole world, one doesn't doubt the current population has succumbed to modernity. Similar health can be observed in physically active people with conservative consumption levels globally.

I'm not really sure what "succumbed to modernity" means in this context. World life expectancy went from 46 years in 1950 to 72.63 in 2020 to 73.16 in 2023. Is that the right metric to look at? If it is, succumbing to modernity doesn't sound too terrible.

Isn't that figure from 1950 also impacted by the fact they just had a major war killing millions of young people prematurely? After all this calculation is done over a longer term than 1 year as far as I know.

Worth noting that the only source for that excerpt from Wikipedia, for the life expectancy, is some NYT article written by a journalist in 1996 which is now paywalled.

That statistic could be skewed by a high childhood mortality rate.

> older people in traditional cultures with healthy physical activity and consumption levels continue to live long regardless

I agree with the point on physical activity, but the implication that traditional cultures have as long or longer lifespans is easily dismissed as inaccurate.

Can it, if we exclude child mortality (and effects of war, resource stealing, etc)?

All so-called "blue zones" are in traditional cultures (food and general lifestyle wise).

Why would we exclude child mortality? It isn't clear to me that isn't an indirect product of culture any more that any other longevity indicator.

Blue zones seems somewhat ambiguous but if I'm understanding correctly, they are small areas of people who live more traditionally surrounded by mostly modern people? Seems like by definition those zones are made up of cherry picked people and it's unclear to me that those aren't just outliers.

Sleep apnea is not exclusively a lifestyle disorder. I have it with a BMI of under 21.