Welcome to the Longevity Blueprint.
I'm Dr.
Linda Friedland,
And I'm so happy to be sharing some ideas with you.
A huge trend in health and longevity right now is measurement,
Specifically the numbers your wearable,
Your watch or your wearable puts in front of you.
If you wear an Apple Watch,
A Garmin,
An Oura Ring,
A Whoop,
You are probably tracking numbers like these every day.
And if you are not,
Question is,
Should you?
You wake up.
Before your feet even touch the floor.
Your wearable may have already told you how you've slept.
Your sleep score could be 62.
Your resting heart rate is elevated.
Your HRV,
Your heart rate variability is down 15%.
What does all this mean?
And if you are watching these measures before you've even had your cup of coffee,
You feel like you're already behind,
Like your body has failed some overnight exam you didn't know you were sitting.
I see this constantly.
Smart people.
Quietly anxious about a number on a screen they don't fully understand.
So let's explore this.
Over three decades of practicing medicine.
I've learned that data without understanding isn't insight.
It's really just noise.
So here's the thesis I want to leave you with today.
The number isn't the whole story.
In this video,
We're gonna walk through what your wearable is actually measuring.
Heart rate,
HIV,
Sleep score,
And a few other signals you've probably seen and wondered about.
We'll talk about what these numbers really mean,
What they don't mean,
And what you can actually do with them.
And then because understanding a number should change how you feel,
Not just what you know.
We'll close with a short practice so you can feel the shift in your own body now,
Today.
Three numbers that do most of the talking.
Your resting heart rate.
This is how many beats your heart beats per minute at full rest,
Usually measured overnight.
Your heart rate or what we used to call it your pulse.
Is the oldest vital sign in medicine.
Now it's just become automated.
Heart rate variability.
This is.
Also spoken of as HIV.
I've created three videos taking a deep dive into HIV because everyone's talking about it.
If you're interested,
It includes breathwork practices.
What is HRV?
It's the tiny variation in time between each heartbeat.
Despite the name,
More variability is actually good.
It reflects how well your nervous system shifts.
Between.
Both being alert and being calm.
A lower HRV usually means strain,
Physical or emotional.
Sleep school?
Is not one measurement,
But it's a blend,
Including total sleep time,
Time to fall asleep,
How often you wake,
And time spent in each sleep stage,
Folded into a single number.
Your device is likely to also track your respiratory rate,
Your blood oxygen,
Your skin temperature.
These are other signals worth knowing,
But for now,
We will just address the three popular measures.
Once again,
I've created a separate talk on each measure for you to follow.
Here's where I want to slow down,
Because this is the part that separates genuine understanding from anxious guessing.
Every number on your watch or your wearable falls into one of three categories.
Measured,
Estimated or inferred.
Remember that could be directly measured.
It's estimated or it's inferred.
What does this mean?
Knowing which is which changes how much weight you should give it.
Measured means a sensor is directly detecting something physical.
Your heart rate,
The optical sensor on my watch,
Is genuinely reading my blood flow,
Beat by beat.
Estimated means that the device takes that raw measurement and runs it through an algorithm to produce something it isn't directly sensing.
HRV is calculated from the pattern of beats.
Your sleep stages,
Light,
Deep REM sleep,
Are estimated from a combination of movement,
Heart rate,
And heart rate variability,
Not directly from your actual brain waves.
A sleep laboratory,
If anyone has ever been into a sleep laboratory,
Uses EEG,
Electroencephalography,
To watch your brain directly.
Your wearable is making an educated guess from the outside.
Inferred is a step further again.
The device or an app layered on top of it draws a conclusion about your state.
Your body is stressed,
You're not recovered.
That's an interpretation,
Not a fact.
Why does this matter?
Because a single bad number is rarely meaningful on its own.
HRV in particular is influenced by alcohol,
A late dinner,
A poor night's sleep,
Even the phases of a menstrual cycle.
None of which means something is medically wrong.
What matters far more is your own trend over weeks,
Not any single morning reading.
Your sleep score specifically.
A device says that you've gotten very little REM sleep.
It's telling you what it estimated from your movement,
From your heart rate patterns,
Not what a clinician who would be watching your brainwaves interprets.
Once you understand what a number is actually telling you,
It stops being a verdict and starts being something useful.
If your resting heart rate is trending up over several days,
It could mean that you're coming down with a virus or maybe it's not a good day to do a fast walk or a run.
Your sleep,
Your hydration,
Your alcohol,
Before assuming anything.
It's often the first gentle signal that your body gives you before anything else changes.
If your heart rate variability is trending down,
That's your nervous system asking for recovery.
It's not a red flag to panic over.
Slow extended exhalations,
A longer out-breath and an in-breath is one of the fastest ways to shift your nervous system back towards calm.
So is a short walk outside,
A lighter training day,
Or simply going to bed earlier tonight.
If your sleep score is low,
Resist the urge to fix it the next night by forcing extra hours.
Look instead at consistency.
The same wake time every day does more for sleep over weeks than any single catch up.
And look at what came before that sleep score.
Were you using screens,
Working late,
Drinking more alcohol,
A late heavy meal the night before.
Or your mind still running through tomorrow's to-do list.
The common thread is your wearable is excellent at showing your trends.
It is not a substitute for how you actually feel.
And it is never a substitute for a conversation with a clinician,
With your doctor,
Who knows your history if you're not well.
Let's feel this,
Not just know it,
For 60 seconds.
Close your eyes.
Breathing gently through your nose for four.
One,
Two,
Three,
Four.
And then slowly breathe out for six.
3,
4,
5,
6.
That longer exhale is the signal that tells your body it's safe to settle.
Once more.
Breathe in gently.
And out long and slow for six seconds.
We.
Four,
Five.
Notice your body.
Drop your shoulders.
Jaw softening.
That's the same shift your wearable would show.
As a rising HRV hours from now.
You don't need the screen to know it's working,
But it's useful.
Keep breathing and open your eyes when you're ready.
So the next time your wearable buzzes with a number,
A low sleep score,
A dip in your HRV,
A heart rate that's a little higher than usual,
Try and remember this.
It's one number,
Not a trend.
Know and understand what's genuinely measured and what's estimated,
What is inferred.
Watch the trend,
Not the single morning reading.
And use that number as an invitation to act.
To breathe,
To rest,
To notice.
Rather than a verdict on how well you're doing.
The number,
The scoring,
The measure isn't the whole story.
In the next series of videos,
We will go deeper.
There are three talks dedicated entirely to heart rate variability and what it reveals about your nervous system.
And another three on REM sleep.
A talk on VO2 max,
Also one on skin temperature and hormonal patterns.
Come back for those.
Until then,
From me,
Linda Friedland,
Age boldly and live well.
