My Longevity Journey

WHOOP MG Review: Improved Accuracy, New Features, and How WHOOP Age Compares to Blueprint’s Speed of Aging

Published

12 months ago

May 14, 2025

Sean Callahan

A full breakdown of WHOOP MG’s new features, performance accuracy, and how it compares to Blueprint’s Speed of Aging results.

Unboxing the new WHOOP MG: WHOOP’s first medical-grade sensor, now bundled with the WHOOP Life membership and advanced features like ECG and WHOOP Age tracking.

Today, I hit 48 hours with my new WHOOP MG, and the upgrades are already clear. One of the most noticeable improvements is heart rate tracking during my runs, which now feels more accurate than ever. I’ve completed two identical runs using WHOOP MG, and each time, the strain score came in slightly lower than it did with WHOOP 4.0. It feels like I need to push a bit harder to reach the same daily strain targets, which suggests the new sensors are both smarter and stricter. I’m all for it.

On top of the hardware improvements, the WHOOP Life membership unlocks a deeper level of insight. From real-time ECG scans to biological age tracking, WHOOP MG is more than just a fitness tracker. It’s a full-fledged health optimization tool.

WHOOP MG vs. WHOOP 4.0 Strain Test

On back-to-back runs at the same speed and distance, WHOOP MG consistently logged slightly less strain than WHOOP 4.0. That might sound minor, but for anyone training by the numbers, it’s a big deal. No more sporadic jumps in heart rate at the beginning of my workout. This suggests the new MG sensors are better calibrated and more precise. You may need to work just a little harder to hit the same thresholds.

If you’ve been using WHOOP as a guide to pace your effort, or to play Don’t Die, the MG upgrade might tighten your game. This aligns well with those of us following a Blueprint protocol where precision matters.

WHOOP Age vs. Blueprint Speed of Aging

This is where things get interesting. According to my recent Speed of Aging blood test from Blueprint, my biological age is 29.1 despite being 45 chronologically. WHOOP MG puts my WHOOP Age at 34.2, which is 11.2 years younger than my real age but about 5 years older than what Blueprint shows.

WHOOP also offers practical suggestions to lower your WHOOP Age further. The two biggest levers for me are more time in heart rate zones 4 and 5 and better sleep. That matches up exactly with what Bryan Johnson has said about sleep being one the most important factors for health and longevity.

New WHOOP MG Features That Actually Matter

I asked WHOOP’s in-app AI to walk me through what’s new in WHOOP MG and give me some stats about my health. Here’s what stands out:

Heart Screener (ECG)

This gives you on-demand ECG readings to track your heart’s electrical activity. It’s not for diagnosing conditions but it’s a useful tool for staying aware of your heart health.

Blood Pressure Insights (Beta)

Still in beta and not yet medical-grade, this feature estimates daily systolic and diastolic numbers. It gives a general sense of cardiovascular wellness over time.

Healthspan

One of my favorite features. It shows both your WHOOP Age and your Pace of Aging. It makes the idea of longevity visible and trackable.

Stress Monitor

This tracks your stress levels in real time and helps you spot patterns. It’s a powerful tool for anyone trying to manage recovery and avoid burnout.

Health Monitor

This screen tracks your key baselines daily including HRV, resting heart rate, respiratory rate, blood oxygen, and more. It’s a quick check on whether your system is staying within a healthy range.

My Health Snapshot Today

Here’s what WHOOP MG reported for me today:

HRV: 34 ms (above my usual range of 26 to 31 ms)
Resting HR: 48 bpm (right in the middle of my normal range)
Respiratory Rate: 13 rpm (slightly lower than usual)
Blood Oxygen: 95% (normal for me)

This snapshot shows my recovery is trending well and my cardiovascular system is doing great. The fact that I can check in with this level of detail daily is part of what makes WHOOP MG so valuable.

Final Thoughts

WHOOP MG feels like a legitimate step forward. It’s a smarter and more powerful tool for people serious about healthspan and performance. Whether you’re tracking sleep, heart rate zones, or biological age, this device gives you the data you need to make informed decisions every day. And for someone already deep in the Blueprint world, WHOOP MG feels like a perfect complement to blood-based insights.

We did our homework before upgrading from WHOOP 5.0 to WHOOP MG, and the jump has been well worth it. If you’re serious about tracking your health and optimizing for longevity, WHOOP MG is one of the most advanced wearables out there. Thinking about joining the WHOOP community? Use my referral link for a free 1-month trial and see the difference for yourself.

WHOOP MG Screenshots

🩺 Disclaimer

The content on I Won’t Die is for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with any health concerns.

🚀 Get Started with Blueprint

Start optimizing your health today with $25 off your first order! Use our referral code to begin your Blueprint journey and take control of your longevity.

🏋️‍♂️ Track Your Sleep, Workouts & Recovery

Boost your performance and recovery with Whoop. Join with my referral link to get a free WHOOP 5.0 and one month free!

📲 Download the I Won’t Die App

Stay ahead with the latest news, updates, and insights. Download the I Won’t Die app now on the Apple App Store and Google Play!

📩 Contact Us

Have tips, photos, or questions? Want to collaborate? Reach out at [email protected] — we’d love to hear from you!

🔗 Stay Connected

📬 Subscribe to I Won’t Die Newsletter

Get the latest longevity breakthroughs, Blueprint updates, and exclusive content straight to your inbox — sign up now!

Up Next

Does Bryan Johnson’s Sleep Routine Actually Work? We Put It to the Test

Don't Miss

New WHOOP 5.0 and Medical Grade Devices: What We Researched Before Upgrading

Click to comment

0 Comments

Oldest

Newest Most Voted

Inline Feedbacks

View all comments

My Longevity Journey

Electrolytes: The Small Habit That Quietly Changed My Recovery

Published

3 weeks ago

April 14, 2026

Sean Callahan

From lab data to daily routine, how one simple addition is improving hydration, HRV, and how I feel every morning.

I’ve tried a lot of electrolyte drinks over the years.

If you’ve ever run a 5K, 10K, half marathon, or marathon, you know the drill. There’s always a sponsor handing out cups along the course. Some are great. Some… you take one sip and immediately regret your life choices.

So I never really thought much about electrolytes beyond race day.

That changed after my labs.

What the Data Actually Said

After my WHOOP Advanced Labs last November, one small thing stood out.

Not a red flag. Not a major issue.

Just a signal.

My BUN and BUN to creatinine ratio were slightly elevated, which often points to mild dehydration or high protein load at the time of testing.

The interesting part is that I already drink a lot of water.

Usually over one hundred ounces a day.

Hydration has always been one of my stronger habits.

But the takeaway was simple.

Water alone is not always enough.

The Adjustment

I did not overhaul anything.

I made a small change.

Electrolytes.

I started adding one scoop of electrolyte powder to about 24 ounces of water each day. On harder training days, or after a sauna or jacuzzi session, I might have two or three.

That’s it.

No complexity. No big protocol.

Just consistency.

What I Noticed

This is where it got interesting.

My HRV started improving.

Not overnight, but steadily.

Recovery scores became more predictable. Morning readiness felt smoother. Less variability.

And one pattern stood out.

If I have a glass of electrolytes before bed, I often wake up with a green recovery on WHOOP.

Not always. But often enough to notice.

There is a tradeoff.

I also wake up at night to use the bathroom more.

Worth it.

The One I Landed On

After trying a few options and doing a bit of research, I landed on:

KEY NUTRIENTS Electrolytes Powder (available on Amazon)

What I like:

No sugar
Sweetened with stevia
No unnecessary additives
Clean ingredient profile
Easy to mix and drink

I started with lemonade and now rotate between:

Strawberry Lemonade
Pink Lemonade
Orange
Lemonade (again, still my favorite)

They also offer a range of other flavors and even unflavored options, which I may try next.

A 90 serving container usually runs around $40, but I’ve seen it closer to $25 when it goes on sale.

Why This Matters

It is about listening to small signals, not about adding another supplement to my daily routine.

My labs did not say “you have a problem.”

They said “there is an opportunity.”

Hydration is one of the fastest levers you can pull, and if your body is human like mine, you’ll feel the results right away!

It affects:

HRV
recovery
sleep quality
training output
how you feel when you wake up

And unlike most things, it responds quickly.

Final Thoughts

The biggest improvements in my health this past year have not come from dramatic changes.

They have come from small, consistent adjustments.

This is one of them.

Easy to implement. Easy to maintain. Quietly effective.

And once it becomes part of your routine, you don’t really think about it anymore.

You just feel the difference.

🩺 Disclaimer

🚀 Get Started with Blueprint

Start optimizing your health today with $25 off your first order! Use our referral code to begin your Blueprint journey and take control of your longevity.

🏋️‍♂️ Track Your Sleep, Workouts & Recovery

Boost your performance and recovery with Whoop. Join with my referral link to get a free WHOOP 5.0 and one month free!

📲 Download the I Won’t Die App

Stay ahead with the latest news, updates, and insights. Download the I Won’t Die app now on the Apple App Store and Google Play!

📩 Contact Us

Have tips, photos, or questions? Want to collaborate? Reach out at [email protected] — we’d love to hear from you!

🔗 Stay Connected

📬 Subscribe to I Won’t Die Newsletter

Get the latest longevity breakthroughs, Blueprint updates, and exclusive content straight to your inbox — sign up now!

My Longevity Journey

Mission Accomplished: My Speed of Aging Result Is In and Blueprint Confirms the Trend

Published

1 month ago

April 6, 2026

Sean Callahan

From 0.95 to 0.67 in a year, with WHOOP now showing 0.60, the signal is clear: steady habits are changing the trajectory.

A few weeks ago, I took another shot at the Blueprint Speed of Aging test due to a bad sample.

This time, it worked.

No failed sample. No retest request. Just a clean blood spot card, a little patience, and now a result I have been waiting to see.

And it’s a good one.

The Number

My new pace of aging came back at:

0.679503063641104

That means my body is aging at about 67% of the expected rate.

Put another way, for every calendar year that passes, my biology is aging closer to eight months.

What makes this result more meaningful is the trend.

In January 2025, my pace of aging came back at 0.95. Now, a little over a year later, it is 0.67.

That’s a real drop. Not a rounding error. Not wishful thinking. A real shift in the rate at which my body is aging.

Blueprint also says I am aging slower than 98.15 percent of people my age who have taken the same test.

What This Test Measures

The Blueprint Speed of Aging test is based on DNA methylation, which looks at how your cells are changing over time.

It’s a measurement of the rate at which your body is biologically aging at the cellular level, not a broad wellness score.

A score of:

1.0 means you are aging at a normal pace
below 1.0 means you are aging more slowly
above 1.0 means you are aging more quickly

So moving from 0.95 to 0.67 in a year is exactly the kind of direction I hoped to see.

A Second Signal From WHOOP

What makes this even more interesting is that my other aging data points tell a similar story.

As of this morning, my WHOOP pace of aging is 0.60.

Different system. Different inputs. Different model.

But the message is almost identical.

And to me that matters.

When independent tools start pointing in the same direction, the story becomes harder to ignore.

What Changed: Nothing Flashy

I have stayed consistent with the same core routine I built last year:

Mediterranean diet
Same supplements I started last year
Daily cardio, averaging about 7 miles of running per day
Strength training 4 to 5 days a week (down from 7)
Better recovery and sleep consistency

That last one matters more than most people think.

I did this without hacks, rather through repetition, day after day.

Why This Result Matters

The best part of this result isn’t the number itself, but the confirmation.

The work is landing.

The changes I made aren’t only improving how I feel or how I perform, but they are showing up in the biology underneath everything else.

That’s what I wanted to know.

The Bigger Picture

A year ago, I was focused on risk reduction of heart disease.

Lower inflammation.
Improve cholesterol.
Stabilize blood sugar.
Get healthier on paper and in practice.

Now the conversation is a little different. The question is no longer just whether I’m lowering risk, but whether I’m changing trajectory.

This result says yes.

Final Thoughts

Now this becomes the new benchmark.

The goal is simple:

Keep doing what works.
Stay consistent.
Protect recovery.
See if the number keeps moving in the right direction or plateaus.

For me, this wasn’t really about one test. It was about being on a better path.

And right now, the path looks better than it did a year ago. 🙌

🩺 Disclaimer

🚀 Get Started with Blueprint

Start optimizing your health today with $25 off your first order! Use our referral code to begin your Blueprint journey and take control of your longevity.

🏋️‍♂️ Track Your Sleep, Workouts & Recovery

Boost your performance and recovery with Whoop. Join with my referral link to get a free WHOOP 5.0 and one month free!

📲 Download the I Won’t Die App

Stay ahead with the latest news, updates, and insights. Download the I Won’t Die app now on the Apple App Store and Google Play!

📩 Contact Us

Have tips, photos, or questions? Want to collaborate? Reach out at [email protected] — we’d love to hear from you!

🔗 Stay Connected

📬 Subscribe to I Won’t Die Newsletter

Get the latest longevity breakthroughs, Blueprint updates, and exclusive content straight to your inbox — sign up now!

My Longevity Journey

Take Two: The Speed of Aging Redemption

Published

2 months ago

March 11, 2026

Sean Callahan

A second attempt at Bryan Johnson’s Blueprint Speed of Aging test, two lancets, warmer hands, and a little more determination.

Back in January I attempted Bryan Johnson’s Blueprint Speed of Aging test.

And it failed.

Not philosophically. Not emotionally. Not metaphorically.

After waiting longer than anticipated for the results, the lab said they simply could not process my sample. Ugh!

A couple weeks ago, Blueprint sent a replacement kit and yesterday I gave it another shot.

Round two.

The Speed of Aging Kit Arrives

The Blueprint kit showed up looking exactly like the last one. Clean packaging, everything neatly organized, and a reminder that this tiny box holds the key to measuring something pretty profound.

Your biological aging rate.

Inside the kit were the usual suspects:

two spring loaded lancets
alcohol wipe
gauze and bandage
the blood spot card
biohazard bag and return envelope

Everything you need to run a small longevity experiment from your kitchen counter. And that is exactly what I did last night!

Preparing for the Finger Prick

Last time I did this test the blood flow was strong and the sample filled quickly.

This time, not so much.

I followed the same advice the Quest technician gave me earlier in the year.

Warm hands.

So I ran them under hot water for a bit and set up my little testing station on the counter.

Alcohol wipe.
Lancet ready.
Sample card open and waiting.

I stared at the lancet again like it was a tiny plastic jack in the box.

The anticipation is still the worst part. I don’t mind at all having vials of blood drawn from my arm, but the anticipation of pricking my own finger is nerve-racking. Ha ha!

Pop. Again.

I pricked my finger and waited for the blood to flow.

It started slowly.

Slower than last time. I massaged my finger and it didn’t help much.

So naturally my brain went straight to the logical conclusion.

Better open a second blood source.

Second lancet.
Second finger. Ouch!

Now I had two active production sites.

Not exactly what the instructions call for, but efficiency matters.

Between the two fingers I was able to steadily blot the sample card until the circle filled and the blood absorbed through to the back.

That’s the key indicator that enough sample has soaked into the card for proper analysis.

Mission accomplished.

The Waiting Game

Once the card was fully saturated, I let it dry for about three hours.

After that it went into the biohazard bag, then into the return envelope.

Now it’s on its way back to the lab via USPS.

Results typically arrive digitally about two weeks after the sample is received.🤞

Why This Test Matters

The Blueprint Speed of Aging test is built on DNA methylation analysis, one of the most advanced methods currently available for measuring biological age.

Instead of looking at a handful of biomarkers, it analyzes epigenetic changes across thousands of DNA sites to estimate how quickly your body is aging. It measures the age of your lungs, blood, liver, kidney, heart, hormones, etc.

In other words, it measures the pace of aging itself, not just risk factors.

My Current Biological Age Signals

While I wait for the results, I already have two other aging indicators.

From my most recent Function Health panel:

Biological age: 35.3
About 10.8 years younger than my chronological age.

And from WHOOP:

WHOOP age: 30.8

WHOOP also tracks pace of aging, which currently shows 0.30x as of this morning.

Meaning my body is aging at roughly one-third the expected weekly rate based on recovery, sleep, HRV, and training load.

Different models. Different inputs.

But the signals are pointing in the same direction.

The Number I’m Watching

The Blueprint result is the one I’m most curious about.

The last time I ran this test in January 2025, my epigenetic age came back at 29.1 years old, roughly 15 years younger than my chronological age.

Since then I’ve doubled down on:

Mediterranean eating, consistent aerobic training, strength work, sleep discipline, and biomarker tracking.

So the big question now is simple…

Did the needle move or did the universe decide to humble me?

We’ll find out in about two weeks.

🩺 Disclaimer

🚀 Get Started with Blueprint

Start optimizing your health today with $25 off your first order! Use our referral code to begin your Blueprint journey and take control of your longevity.