Matthew Walker

The reason is because sleep, unlike those two other criticals of health, which is diet and exercise, is very difficult to subjectively estimate.

So if I were to ask, you know, Eric, how many times have you worked out in the past week?

You'd be able to tell me.

How cleanly or how poorly have you been eating in the past week?

You could tell me.

But if I was to say to you, you know, Eric, how much deep sleep did you get last Tuesday?

And if you don't have a sleep tracker, you'd say, I don't know.

And so there's something useful about tracking, especially a non-conscious process that I think is meaningful to many.

And often in medicine, we say what gets measured gets managed.

And there is that trite sort of statement.

I do think that that's still true for sleep.

So many people I've spoken to have, for example, markedly reduced the amount of alcohol consumption.

because they've been seeing the huge impact that alcohol consumption in the evening has on their ring, smart ring data as a consequence.

So overall, I think they're pretty good.

When people ask me what's the best sleep tracker, I usually say it's the one that you wear most frequently.

Because if I come up with a band, headband, chest straps, all sorts of different things, and it's 100% accurate, but after three uses of it, you stop using it, that's a useless sleep tracker.

So I like to think about sleep trackers that are low friction and no friction.

When we go to sleep, we take things off.

We don't put things on.

That's why I like things like the ring.