personal training

The Month Cartilage Science Changed Everything — And What It Means For Your Knees Right Now

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A few weeks ago I wrote about my own knee osteoarthritis diagnosis — the swollen left knee that wouldn’t quit, the 30cc of fluid my orthopedic surgeon’s staff drained in his office, the Baker’s cyst, the MRI findings, the cortisone shot, the pending hyaluronic acid injection series. I promised updates as things developed.

Here’s the update: I just completed a multi-day karate special training. Strenuous, demanding, the kind of training that tests your entire body and your mind in equal measure. My knee is still not perfect. The inflammation is ongoing. And I did it anyway — not because I was reckless, but because the emerging science told me I should. And because I’m in the business of continuing to do the things that I love, that give my life meaning.

More on that in a minute.

First, I want to tell you about what has happened in cartilage science in the last several weeks. Because I think we are genuinely watching a paradigm shift in real time. And if you have osteoarthritis, or know someone who does, you need to understand what’s coming.

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Three Pieces of Research. One Converging Message.

Let me lay out what’s happened in quick succession, because the timing is remarkable.

**Piece One: The Biological Framework (Howard Luks, MD)**

Howard Luks — sports medicine orthopedic surgeon, one of the most evidence-based voices in joint health — has been arguing for years that the conventional model of osteoarthritis is simply wrong. The “wear and tear” framing that leads patients to stop moving, stop loading, stop doing the things they love is not supported by the biology. As Luks writes, cartilage is a living, biologically active tissue that gets its nutrients from synovial fluid — and the only way synovial fluid circulates through cartilage is through compression and release. Load the joint, unload it, load it again. Movement nourishes cartilage. Inactivity starves it.

The primary driver of OA progression, Luks argues, is not mechanical grinding but chronic low-grade inflammation — specifically the cytokines IL-6 and TNF-alpha — that poisons the cellular environment where chondrocytes (cartilage-making cells) are trying to do their jobs. Your knee is downstream of your systemic biology. Everything that reduces your inflammatory load protects your joints.

This framing matters because it completely reorients what you should be doing about OA. Not resting. Not restricting. Training smartly, sleeping well, eating clean, managing stress — these are joint protection strategies, not just general wellness platitudes.

**Piece Two: The Exercise Intensity Study (Song & Meng, Medicine, May 2026)**

A randomized controlled trial published in Medicine in May 2026 put 120 patients with moderate knee OA (Kellgren-Lawrence Grade 2-3) into four groups: low-intensity aerobic exercise (50-60% heart rate reserve), moderate-intensity (60-70% HRR), high-intensity (70-80% HRR), or a control group. Three sessions per week, 30 minutes of treadmill walking or stationary cycling, continuously heart rate monitored, for 12 weeks.

The results were remarkable across every measure they tracked.

The high-intensity group saw a 28.5% drop in serum CTX-II — a direct biomarker of cartilage breakdown — over 12 weeks. The control group got slightly worse. On MRI, the high-intensity group increased medial cartilage thickness by 4.8% and volume by 4.2%. Pain dropped 52.5%. WOMAC scores — a comprehensive measure of OA pain, stiffness, and function — improved 45.3%. The 6-minute walk test improved by 71 meters, nearly triple the established threshold for clinical meaningfulness. 80% of high-intensity participants achieved clinically meaningful pain relief.

No serious adverse events. Zero dropouts due to exercise-related problems. These were people with moderate osteoarthritis exercising vigorously for 12 weeks.

Loading the joint did not thin the cartilage. It thickened it.

The dose-response data showed a threshold effect between 60-70% HRR where the benefit curve gets dramatically steeper. For most people, the sweet spot appears to be roughly 65-75% of heart rate reserve — vigorous but sustainable. The authors’ own conclusion: current exercise recommendations for knee OA patients are overly conservative, and many patients could safely tolerate and benefit from significantly more intense exercise than has traditionally been prescribed.

**Piece Three: The Stanford Breakthrough (Agarwal, Su, Ancel et al., Science, June 12, 2026)**

And then, just weeks after the Song & Meng paper, Stanford Medicine published what may be the most significant development in OA research in decades.

The study, published in Science, identified a single aging-related enzyme — 15-hydroxyprostaglandin dehydrogenase, which the researchers term a “gerozyme” because it accumulates with age and drives tissue degeneration — as a master regulator of cartilage aging. Block this enzyme, and something remarkable happens: existing chondrocytes undergo transcriptional reprogramming to a more youthful state. They don’t need to be replaced. They don’t need stem cells. They just need the aging brake released.

In aged mice, small-molecule inhibitors of 15-PGDH promoted cartilage thickening and regeneration of functional hyaline cartilage — the smooth, load-bearing kind, not scar tissue. The treatment reversed natural age-related cartilage thinning, improved joint function, and when administered after simulated ACL injuries, strongly mitigated post-traumatic OA progression and associated pain.

Most compellingly: human OA cartilage explants from total knee replacement surgeries — worst-case specimens, cartilage so degenerated it required surgical removal — showed decreased degradation markers and evidence of new articular cartilage formation when exposed to the 15-PGDH inhibitor in the lab.

And crucially, an oral version of the 15-PGDH inhibitor has already completed Phase 1 safety trials for age-related muscle atrophy. The safety profile is established. The path to a cartilage-specific clinical trial is shorter than starting from scratch.

Helen Blau, the Stanford researcher leading this work, put it plainly: “Imagine regrowing existing cartilage and avoiding joint replacement.”

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Why This Convergence Matters

Three independent lines of research — a clinical framework, a randomized controlled trial, and a molecular biology breakthrough — landing in the same window, pointing in the same direction.

The old model: OA is irreversible mechanical wear. Cartilage grinds down. Rest what’s left. Manage pain until you need a new joint.

The emerging model: OA is primarily a biological failure — chronic inflammation, aging-related molecular brakes, a cellular environment that has become hostile to the very cells responsible for maintaining cartilage. And biological failures can be addressed biologically. Through exercise. Through systemic inflammation management. And potentially, soon, through targeted molecular intervention that allows your own chondrocytes to become youthful again.

This is not incremental progress. This is a paradigm shift.

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The Caveats

I’m not going to oversell this, because we all deserve the full picture.

The Stanford study showed human cartilage regeneration in vitro — in a lab dish, not in a living human patient. Mouse-to-human translation in cartilage research has historically been difficult. The jump from promising preclinical results to clinical reality is where most breakthroughs stumble. Realistically, if the 15-PGDH inhibitor clears Phase 2 and 3 trials for cartilage regeneration, you’re probably looking at 3-5 years minimum before it’s available to patients. That’s fast by drug development standards. It is not imminent.

The Song & Meng study lasted 12 weeks with 120 participants. The authors themselves note that the short-term MRI cartilage changes may partly reflect alterations in cartilage hydration rather than true structural remodeling, and that longer-term studies are needed to confirm genuine tissue regeneration.

And the Luks framework, while compelling and well-supported, is still fighting against decades of conventional medical conservatism. Most orthopedic surgeons are still telling their OA patients to take it easy (including my own, sigh).

What I’m saying is: the direction of the evidence is clear and genuinely exciting. The clinical applications require patience.

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What I’m Doing Right Now — And What You Should Consider

I want to share my own protocol, because I think it’s the most practical thing I can do.

**Exercise intensity as medicine.** Based on Song & Meng, my therapeutic target on the bike is 65-75% of heart rate reserve. With my resting HR of 45 and max HR of 175, that’s roughly 128-143 bpm — Whoop Zone 3, comfortably hard, sustainably challenging. Ideally three sessions per week, 30 minutes of work. This is the study protocol, and I’m treating it that way.

**VMO strengthening.** My MRI showed lateral patellar subluxation — my kneecap tracks too far to the outside, which is a primary driver of my patellofemoral OA and inflammation. Terminal knee extensions, backward sled drags (Kelly Starrett’s recommendation), and heavy standing bike climbs are my primary VMO tools. The patella tracks where the VMO tells it to. Strengthen the VMO, improve the tracking, reduce the grinding.

**Systemic inflammation management.** The Slowfit Method® pillars are not just training advice — they are, in the context of OA, direct joint protection strategies. Sleep quality, clean nutrition, stress management, lean body composition: all of these reduce the inflammatory cytokine load that drives OA progression. Every pillar is working in service of every other pillar.

**Voltaren topically, not Aleve systemically.** Topical diclofenac delivers NSAID-level anti-inflammatory action directly to the joint with roughly 6% of the systemic absorption of oral NSAIDs. Lower risk, more targeted. My default post-activity tool. I don’t love the idea of leaning on NSAIDs for anything, but as Kelly Starrett says, to stay ahead of the snowstorm, you’ve gotta sweep the front steps every hour. One of those sweeps, for me, is a little Voltaren.

**Normatec for lymphatic clearance.** Pneumatic compression after training sessions to move fluid and support recovery. Not a treatment — a recovery tool.

**The HA injection series coming next month.** Hyaluronic acid viscosupplementation to restore the joint’s natural lubricating environment before I start loading it with Starrett-level work.

**And the karate.** I just completed a demanding multi-day special training that would have been unthinkable six months ago when the knee was at its worst. Not pain-free, not without managing it carefully before, during, and after. But done. Because the evidence told me that movement is the medicine, fear of movement is the enemy, and an active 57-year-old with moderate patellofemoral OA who keeps training is doing more for his cartilage than one who sits on the couch waiting to feel better.

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A Note on Howard Luks

I’ve reached out to Dr. Luks directly for his perspective on the Stanford study. His read on how the 15-PGDH research intersects with the exercise intensity data — and what it means clinically for active patients managing OA right now — is worth having. I’ll update this post or publish a follow-up when I hear back.

If you’re not already reading Luks’ Substack, you should be. He is one of the authentic, most honest voices in orthopedic medicine writing for a general audience today.

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Why We Do This

The oft-cited Kelly Starrett — physical therapist, coach, mentor, and one of the clearest thinkers in the movement and performance space — talks about training in terms of “spending credits.” The idea is simple: we put in the work so that we can spend the credits on the activities we love. The training is not the point. The training is what makes the point possible.

For me, that means triathlon. It means karate. It means being able to toe the start line at the Escape from Alcatraz, to show up for special trainings, to get smashed around on my surfboard, to keep doing the things that make me feel most alive at 57. The knee work — the Zone 3 cycling sessions, the VMO strengthening, the backward sled drags, the HA injections, the Voltaren, the Normatec, the sleep and nutrition discipline — none of it is the destination. It’s the price of admission for the life I want to keep living.

That’s what the Slowfit Method® is ultimately about. Not optimization for its own sake. Training as a means to a life fully lived. And the emerging science around OA — exercise as cartilage medicine, chondrocytes capable of becoming youthful again — tells us that life can be longer, more active, and more capable than we previously had any right to expect.

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The Slowfit Method® Take

None of this surprises me from a Slowfit Method® perspective. What it does is give us a richer, more precise scientific language for what we’ve been building here.

The Slowfit Method is, at its core, a biological framework for human performance. We train because training creates adaptive signals. We treat sleep, nutrition, stress management, and recovery as pillars — not accessories — because your body is a system and every pillar affects every other one. We monitor training load and recovery state because the dose matters.

The emerging OA science adds a beautifully specific prescription: the active person navigating knee osteoarthritis should not back off. They should lean in — smartly, progressively, with heart rate guidance, with the other pillars in order. The goal is to provide the biological stimulus your cartilage needs, maintain the synovial fluid circulation that nourishes chondrocytes, and keep the systemic inflammatory environment as calm as possible while you wait — with genuine hope now — for the molecular therapies that may soon be able to do what no drug has ever done before.

Repair the joint itself.

More updates to come. In the meantime, keep moving. Your cartilage is counting on it.

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Take the Slowfit Method® With You

If you want to put these principles into daily practice, the Slowfit Method® app is now available on iOS. Training guidance, recovery protocols, and the full Slowfit Method® framework — built into a tool you can use every day. I’ve been building this for a while and I’m genuinely proud of what it’s become.

Get the app

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*Nothing in this newsletter constitutes medical advice. If you’re dealing with joint pain, please see a qualified sports medicine physician or orthopedic surgeon. The information here is intended to complement — not replace — professional medical guidance.

Questions, reactions, pushback? Hit reply. I read everything.

Keir

Foghorn Fitness

foghornfitness.com | foghornfitness.substack.com

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Foghorn Fitness is home to The Slowfit Method® — a science-backed, whole-person approach to human performance. If someone forwarded this to you and you’d like to subscribe, we’d love to have you.

The App I Built Is the Opposite of Everything I’ve Been Warning You About

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“This phone is the devil”

— a childhood friend, via text, this morning

He’s getting off Instagram. Can’t say I blame him.

I’ve spent years writing about your phone. Specifically, about what it’s doing to you. (And to me.)

In January 2024 I wrote about Johann Hari’s Stolen Focus and the trillions of dollars arrayed against your ability to pay attention. In February 2024 I went deeper on why it’s so hard to focus — the dopamine dependency, the slot-machine mechanics, the infinite scroll engineered to exploit our evolutionary hard-wiring. In October 2024 I wrote about Jonathan Haidt’s The Anxious Generation and what the smartphone has done to our kids. And before all of that, Cal Newport’s Digital Minimalism convinced me to deliberately downsize my iPhone use, strip the social media icons off my home screen, and mute the notifications pulling my attention toward that hunk of plastic and glass in my pocket.

The research is clear. Maggie Jackson, in Distracted, put it as starkly as anyone: with our attention scattered among the beeps and pings of a push-button world, we are cultivating a culture of distraction and detachment.

I didn’t just write about this stuff. I lived it. A while back I documented my own month-long attempt to break up with my iPhone — the rubber band around the phone, the grayscale screen mode, a Giants game where I didn’t look at a screen once (one of my prouder moments). The whole messy field report is in the Phone Breakup series if you want to go down that rabbit hole. The short version: it’s hard, it’s worth it, and I failed more than I succeeded. But I kept trying.

And then I went and built an app.

I know.

Here’s the Thing I Had to Reconcile

When I first started thinking seriously about building the Coach Keir AI app, I had a problem. Not a technical problem — that was my developer Alex’s department. Rather, I had to address a philosophical one.

I had spent years making the case that our smartphones are attention-harvesting machines designed by very smart, very well-funded people to keep us glued to screens as long as humanly possible. I had written about Anna Lembke’s Dopamine Nation and the way pleasure-seeking loops get forged into deep neural grooves. I had cited the Center for Humane Technology and Tristan Harris’ warnings about what engagement-maximizing technology is doing to human cognition. I had recommended Catherine Price’s How to Break Up with Your Phone to pretty much every athlete I coach.

And I was about to add another app to the App Store?

The only way I could do it in good conscience was to build the opposite of what everyone else was building.

So that’s what I did.

What “The Opposite” Actually Looks Like

No infinite scroll. No push notifications engineered to pull you back. No streaks. No engagement metrics. No algorithmic filler designed to keep your eyes on the screen.

The app gives you what you need and sends you back to your life. That’s the design spec. Use it as a springboard, not a slot machine. Remember Patagonia’s famous “Don’t Buy This Jacket” ad in The New York Times? Same energy. I want you to use this app. I also want you to use it for two minutes and then go to sleep.

Speaking of sleep.

Meet “Julie”

One of my longtime Foghorn athletes — I’ll call her Julie — has a bedtime habit that will be familiar to a lot of you.

She gets into bed at 10:30. She picks up her phone to “check one thing.” An hour later she’s still on Instagram, heart rate quietly elevated, nervous system humming, cortisol doing what cortisol does when you’ve been consuming a high-speed feed of other people’s highlight reels for 60 consecutive minutes. She falls asleep somewhere around midnight. Her Whoop recovery score the next morning is dismal. She’s groggy, short-tempered, and reaching for an extra cup of coffee by 9 a.m.

We’ve talked about this in our sessions. A lot. She knows the science. She’s read the posts I’ve sent her. She knows that the blue light from her phone suppresses melatonin, that the emotional arousal of social media keeps her sympathetic nervous system activated exactly when she needs to be downregulating, that the unpredictable reward schedule of Instagram is the same mechanism that keeps people at slot machines.

Knowing isn’t the same as doing.

So a couple weeks ago I told her to try something different. Instead of reaching for Instagram when she gets into bed, open the Coach Keir AI app and type in what she’s feeling.

Here’s exactly what Coach Keir said:

Julie, put the phone down right now. Instagram at 10:30pm is gasoline on the anxiety fire — the algorithm is literally designed to keep your nervous system activated. I know it feels like comfort but it’s the opposite.

Here’s your downregulation breathing protocol. Do this right now: Close your mouth. Keep it closed throughout. Start with a quick body scan from head to toe — wherever you find tension (jaw, shoulders, chest), let it dissolve on your exhales. Now breathe:

• 4 counts in through your nose, belly-led

• 8 counts out through your nose, slow and controlled

• No aggressive pauses, circular and gentle

• When your mind wanders to work anxiety, gently bring it back without judgment — no self-criticism, just return to the breath. The extended exhale is the physiological key — it directly activates your parasympathetic nervous system. Your body cannot stay in fight-or-flight with a long nasal exhale. This isn’t woo, it’s autonomic nervous system science. Do this for 5 minutes. Then finish with one big inhale all the way to the top, slight hold, then the longest possible nasal exhale you can sustain. That final exhale is your reset.

One more thing: If you want guided support for this, Headspace has excellent sleep meditations that pair perfectly with this protocol. It’s the only meditation app I use and endorse. Your move: Phone face down across the room. Lights out. Start breathing. You’ve got this Julie. Goodnight.

Two minutes to read that. Five minutes to do the breathing. She was asleep by 10:45. That’s not a miracle. That’s a tool.

The Irony Is Intentional

Yes, this requires using a phone to stop using a phone. I get it. That’s a real tension and I won’t pretend otherwise.

But here’s what I’d offer: the problem was never the device. It’s what the device is typically used for. Instagram, TikTok, and the news feed are engineered for maximum engagement. A breathing protocol is not. One is a slot machine. The other is a tool.

Catherine Price’s framework — ask yourself “What for? Why now? What else?” before you reach for your phone — is the right instinct. Most of the time, the answer to those three questions is damning. But occasionally the answer is: I need a downregulation protocol so I can sleep. And for that, a phone can actually help.

The Slowfit Method® has always been about intentional choices. Being deliberate about how and why we are living our lives, rather than just pouring more water into a glass that is already overflowing and hoping for the best. The app is the method in your pocket. Use it intentionally. For two minutes. Then put it down.

That’s the whole pitch.

Download My App

What “Julie” Said Last Week

“Honestly? I forget sometimes and I end up on Instagram anyway. But when I remember to open the app instead, I’m asleep in under 15 minutes. When I don’t, I’m awake until midnight and I hate myself a little.”

Not a case study. Not a controlled trial. Just a Foghorn athlete who found one thing that works slightly better than the thing that wasn’t working.

Which is more or less what the Slowfit Method® is for.

My buddy from childhood is getting off Instagram. Good for him.

The phone doesn’t have to be the devil. But it’s up to us to make sure it isn’t.

Stick around.

Best,

Keir

P.S. The app is free to download. Coach Keir AI is available to all users. The full Vault — 270+ books, podcasts, tools, and on-demand workouts — unlocks with a paid subscription. Download here.

P.P.S. Want to work on sleep, distraction, or any other pillar of the Slowfit Method® with a real human coach? That’s what the 1:1 work is for. Book a session at foghornfitness.com. I have availability. Hit that button.

Book a Session

P.P.P.S. Paid Substack subscribers get the deeper dives and the full resource library behind every pillar. Upgrade here.

P.P.P.P.S. The new Foghorn Fitness site just launched. All ten pillars, the full method, everything in one place. foghornfitness.com.

What Do You Want Written on Your Tombstone?

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I know. Dark opener for a fitness newsletter, right?

Bear with me.

This is the first in a series of deep dives on the ten pillars of the Slowfit Method®. My framework for being as healthy and happy as possible, developed over thousands of hours of coaching, reading, and frankly experimenting on myself and anyone who’d let me. If you’re new here, the full method is at foghornfitness.com — worth a look before or after you read this.

I’m not kicking off with a workout. Not with a supplement protocol. Not even with a breathwork technique, though that’s coming.

I’m starting with a question about your funeral.

Because everything else flows from the answer.

Pillar #1: Purpose

When I designed the Slowfit Method®, I had to decide where to start. Ten pillars, each important. But one has to come first.

The answer was obvious: If you don’t know why you’re here, nothing else is oriented correctly. You can optimize your sleep, nail your Zone 2 training, build a meditation practice. And still feel like you’re running on a treadmill going nowhere if the whole machine isn’t pointed toward something that matters to you.

So we start with purpose. Your mission. Your reason for being.

Your answer to: Why am I here? And most of us have no idea. That’s OK! Keep reading, let’s see if I can help get you there, or at least pointed in the right direction.

The Tombstone Exercise

World-renowned performance psychologist Dr. Jim Loehr has spent his career thinking about exactly this. His book Leading with Character: 10 Minutes a Day to a Brilliant Legacy puts it plainly: at the end of your life, people won’t be praising your money, your title, or your status.

They’ll remember your character. What you gave. How you made them feel.

Loehr’s companion piece, The Personal Credo Journal, walks you through the hard work of crystallizing your life’s purpose. Prompts like: What are the major themes in your life? What words describe you at your best? At your worst? Are you more of a giver or a taker?

I’ve been working through the journaling myself. I won’t pretend it’s comfortable. Nor that I’ve got this thing dialed. I basically find myself disappointed in myself about something I’ve done or not done every single day. But I’m developing a much clearer sense of what I’m actually meant to be doing here. And that clarity is making me more intentional about how I spend my time. The things I choose to do that serve my purpose. The things I choose not to do that don’t. Where I direct my focus and attention (and where I don’t).

I’m also mindful here of Tsutomu Ohshima, the founder of Shotokan Karate of America (the school to which I belong), who famously said: “We must look at ourselves with the strictest eyes.” That’s the work. Not brutal self-criticism. Clear-eyed self-knowledge. Being honest with yourself, no BS. You don’t need to be a karate-ka (though it helps!) to appreciate this one.

This is why Pillar #1 is Purpose. Not double-unders. Not red-faced Tabata on a spin bike. In fact, this heavy topic is something I’ll address with new Foghorn athletes fairly early in a new training relationship. Because everything else flows from there.

Arthur Brooks on Happiness and the Second Curve

A book I kept coming back to while developing this pillar: Arthur C. Brooks’ From Strength to Strength: Finding Success, Happiness, and Deep Purpose in the Second Half of Life. Brooks is a Harvard professor, social scientist, and The Atlantic’s happiness columnist.

The book resonated with me personally. It helped put into perspective my own career arc. Big firm litigator to sports entrepreneur running a major big wave surfing contest to human performance coach. On paper, this doesn’t look like a clean trajectory, does it?

Brooks’ framework made sense of it.

As we age, our “fluid intelligence” naturally diminishes. The dynamism, the raw idea generation, the ability to out-grind everyone in the room. That fades.

But our “crystallized intelligence” rises. The ability to draw on a lifetime of experience, synthesize knowledge, teach, and mentor. If you can let go of your attachment to the first curve and lean into the second, you’re on the road to a different kind of success. And a much deeper kind of happiness.

This is where I’ve landed. I’m here to share what I’ve learned (and continue to learn). This is my purpose, and in it I’ve found a sense of peace.

Brooks defines happiness not as a feeling but as a combination of elements: enjoyment, satisfaction, and purpose. That third ingredient is the one most people skip. We optimize for enjoyment. We track our accomplishments for satisfaction. But purpose is the ballast. Without it, the good days feel thin and the hard days feel bottomless.

His prescription is strikingly aligned with what I built the Slowfit Method® around. Detachment from empty rewards. Genuine service to others (like you!). Deep relationships. Some form of contemplative practice.

Not hustle more, achieve more. That’s an endless treadmill. Instead be thoughtful—mission-focused—along the way. And slow down, go deeper, figure out what actually matters. Focus your efforts on that.

What the Science Says

Just like everything else I write about here, this isn’t soft stuff. The research treats purpose the same way it treats sleep quality or exercise frequency. It’s a health variable.

A 2024 peer-reviewed study found that purpose in life is a more robust predictor of mortality than life satisfaction itself. People with the highest sense of purpose had a 46% reduced risk of mortality compared to those with the lowest. They were 24% less likely to become physically inactive. And 33% less likely to develop sleep problems.

Then in the fall of 2025, UC Davis published findings from a 15-year study of more than 13,000 adults. People with a stronger sense of purpose were 28% less likely to develop cognitive impairment, including mild cognitive impairment and dementia. The effect held across racial and ethnic groups and remained significant even after controlling for education, depression, and the APOE4 gene—a known genetic risk factor for Alzheimer’s.

As lead researcher Dr. Aliza Wingo put it: purpose helps the brain stay resilient with age. Her co-author, UC Davis neurologist Dr. Thomas Wingo, added something I’ve been saying for years in different words: purpose is something we can nurture. It’s never too early or too late to start thinking about what gives your life meaning.

And the biological punchline: people with higher purpose scores show reduced epigenetic aging. They are aging more slowly at the cellular level.

So yeah, purpose isn’t a soft goal. It’s a physiological variable.

So What Do You Actually Do?

Start with Loehr’s tombstone exercise. Not morbidly. Seriously.

Sit somewhere quiet and write out, in three to five sentences, what you’d want your obituary to say. Not your title. Not your achievements. Not your stock portfolio. The kind of person you were. The impact you had. What people will remember.

Then ask: is the life I’m actually living pointed toward that?

Not perfectly. Nobody’s life is perfectly aligned with their stated values. But roughly. Generally. Is the trajectory right?

If yes: keep going with more intention.

If no, or “I’m not sure”: that’s useful information. That’s where the work starts.

That work, figuring out why you’re here and structuring your life accordingly, is in my view one of the most important health interventions available to you. More important than your VO2 max. More important than your sleep score. More important than your supplement stack.

What to Read

Want to dig a bit deeper on your own? Start with Leading with Character and The Personal Credo Journal by Jim Loehr.

Then From Strength to Strength by Arthur Brooks. And his follow-up, Build the Life You Want (co-written with Oprah Winfrey, which sounds odd but is genuinely good).

For a more philosophical angle: Iddo Landau’s Finding Meaning in an Imperfect World. His central argument is that most of us are far too hard on ourselves when we conclude our lives lack meaning. Your life is almost certainly more meaningful than you think.

Next up in this series: Mindset—specifically, why the story you tell yourself about your own abilities, how you perceive stressors, how you view the world around you— is one of the single most important variables in your health and performance.

Stick around.

Best,

Keir

P.S. Want to work through Purpose — and all ten pillars — with a real human coach? I work with clients 1:1 in person in San Francisco and via Zoom. Book a session at foghornfitness.com.

P.P.S. Paid Substack subscribers get deeper dives, workout programming, and access to archived content behind the paywall. Upgrade here.

P.P.P.S. Want the Slowfit Method® in your back bpocket? Coach Keir AI is trained on all ten pillars and ready to answer your questions 24/7. Download the new Slowfit Method app.

P.P.P.P.S. Plus, the new Foghorn Fitness site just launched! All ten pillars, the full method, and everything else in one place. Check it out at foghornfitness.com.