Founder, Rethryv

Dr. Matt Walker

Longevity and cardiometabolic health expert, twenty-plus years in practice, and a family man who coaches his kids' teams. Today he runs Rethryv — the metabolic health and longevity program he built after his own bloodwork told him something his training never had.

See how Rethryv works His credentials

Credentials & training

Who he is, and why he's the one reviewing your care.

Dr. Matthew Guy Walker is a licensed chiropractic physician whose post-doctoral education reads like a specification for a metabolic longevity program — functional medicine, clinical nutrition, neurophysiology — layered on top of twenty-plus years of reading real patients.

Doctor of Chiropractic Completed his D.C. education while holding a full rugby scholarship and playing at a semi-professional level.
Licensed chiropractic physician Active state licensure, held continuously since he entered practice. Rethryv works with clients nationwide.
Post-doctoral certifications Functional medicine, clinical nutrition, spinal biophysics, pediatric neurophysiology and personal injury. Every one of them research-based — chosen to turn data into evidence he can use on the person in front of him.
Twenty-plus years in practice Thousands of patients have been under his care since he opened his first practice at 28 — two decades of reading real bodies, not just research.
Metabolic & longevity focus The disciplines a longevity program actually runs on — metabolic function, glycemic regulation, inflammation, recovery, body composition and nutrigenomics — are the ones he spent years certifying in and then a decade applying. It's why he thinks about care as a system, not a series of appointments.
Founder, non-profit Built an organization supporting athletes who wanted to become chiropractors, with more than a thousand doctors following him into it.

Biography

Start with the person, not the résumé.

Community-based and genuinely so. He sits on non-profit boards, stays engaged with faith-based organizations, and coaches his kids' teams — and he'll give you the same reason every time.

“You must give to receive.”

The version he says out loud more often: you've got to give them your time, talent, and treasures. Rethryv is the infrastructure he's building so he can give back everything he's learned — to help everybody, everywhere, no matter where you're at in life.

Coaching

On the sideline for his kids' teams more often than not — and usually the one running practice.

Fixer-uppers

A house that needs work is a feature, not a problem. He'd rather do it himself.

Wilderness

Happiest a long way from pavement, on trips that ask something of him.

Beaches, with his wife

The trade-off for the wilderness trips, and the one he never argues about.

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He's down to earth, by his own description. He likes a house that needs work and the satisfaction of fixing it himself. He'd rather be deep in the wilderness than in a hotel lobby, though he and his wife will happily trade the woods for a beach when the chance comes up.

What ties it together is that his instinct is to give — to the people he connects with and the causes he believes in. Ask people who've worked with him and the same words come back: humble about what he's accomplished, quick to raise other people up, more interested in building a team than a personal brand. He wants to help the people in his own community with their businesses and their health, and he has never treated those as separate problems.

He also races. He competed for Team USA and finished 6th in a World Championship swim/bike, then completed his 13th Ironman on his way to Legacy status.

Then his own bloodwork told him something his training never had.

From the outside he looked like the definition of health — multiple Ironman finishes, relentless discipline, the kind of lifestyle people call peak performance. Like most driven people, he'd equated effort with health. What he actually found was metabolic decline running quietly underneath all of it.

You can look healthy, perform well, and still not be truly well.

It broke an assumption he'd never thought to question. Outward fitness and internal health are not the same thing — real health is how well the body works at a systems level: energy regulation, recovery, inflammation, blood sugar stability, resilience.

So he went looking for the mechanism instead of accepting the decline. Advanced diagnostics, deeper analysis, intentional sequencing. He stopped chasing isolated fixes, started addressing root causes, and rebuilt his own health from the ground up.

Then he hit the harder problem: the level of care that worked for him isn't the level of care most people can get. Not because the knowledge is missing — because nobody is looking at all of your data at once, and nobody is there on the ordinary days that actually decide the outcome.

Closing that gap is what Rethryv does. Running it is what he does now.

You don't have to guess at your own health.

Rethryv reads every part of it together, then guides you through what to do about it.

See how Rethryv works

Metabolic longevity

Where Rethryv's philosophy comes from.

The program isn't a collection of tactics he assembled. Every principle in it traces back to something he trained in, then spent years testing on real people.

The shift is from subjective observation to continuous, data-driven metabolic engineering.

Traditional care leans on retrospective recall — how have you been feeling, what have you been eating — which is unreliable at best. Rethryv replaces that with a real-time, continuously evolving map of one person's biology, read by someone trained to interpret it.

Functional medicine Where the first principle comes from: the body operates as an interconnected system. Symptoms are patterns, not isolated faults — so the program looks for the mechanism underneath rather than treating the complaint.
Clinical nutrition The four metabolic pillars below are his. Not calorie math — glucose curves, muscle as the organ of longevity, fiber as a mechanical tool, and the clock your metabolism actually runs on.
Neurophysiology Why sleep, recovery, stress load and nervous-system regulation are treated as metabolic inputs rather than lifestyle extras.
Spinal biophysics A measurement discipline. It's where the habit of demanding objective proof before and after an intervention comes from — and why every phase of Rethryv is benchmarked instead of assumed.
Systems thinking The reason two more principles exist: sequence matters more than intensity, and clarity increases compliance. He builds care as an ordered system with a critical path, not a pile of good advice.

The four metabolic pillars

Every plan is individual, but all of them are built on the same four non-negotiables.

Glycemic precisionFlattening the glucose curve. Fewer high-frequency insulin spikes protects the pancreas and limits the glycation of proteins that accelerates aging.
Cellular fuelingProtein prioritized to defend muscle mass — the organ of longevity — and fats chosen around how your genetics actually process them.
The fiber matrixFiber as both a mechanical and a prebiotic tool: it slows nutrient absorption and feeds the microbiome that immune resilience depends on.
Circadian signalingWhen you eat matters as much as what. Feeding windows aligned to your internal clock to maximize fat oxidation and cellular self-cleaning.

What he's doing now

Rethryv.

A metabolic health and longevity program for people who know something is off — even after being told they're fine.

Real optimization means every variable of your life gets looked at, in context, in real time. Not a protocol handed down and left to chance — a plan built around your biology, your data, and what you're actually trying to do with your life, then guided every single day.

Every variable, together

Bloodwork, genetics, sleep, glucose, nutrition, movement, stress, recovery — read as one interacting system, because the same habit produces different results in different bodies.

A plan built on your biology

Comprehensive diagnostics set the baseline. Clinical interpretation turns it into a prioritized strategy: what matters most, what comes first, how each piece connects to the next.

Technology that sees all of it at once

Continuous data streams into one place where it can be interpreted together rather than one report at a time. That whole-picture read is what lets the care team act precisely instead of generally.

Guidance on the days that decide it

Change doesn't happen on a call. It happens in daily decisions and moments of friction. Rethryv puts support exactly there — adjusting as conditions change, catching friction before it becomes failure.

Rethryv

Find out what your own data says.

What's included, how it starts, and who it's for — all of it lives on the Rethryv site.

See how Rethryv works