Sam Tackeff 👋

Co-Founder @ – online fitness + mindfulness. Culinary Adventurer. Runkeeper / Square / Omnivore Books. Exeter/Wellesley

[Sam Tackeff 👋 @alphaprep]

If you don't have enough time this week.... quit something. Seriously. I love updating my "not doing" list. Do you have one? It's liberating.

[Jonathan Levitt @JWLevitt]

I've been getting bloodwork 3-6 times a year since 2014. I have 51 panels going back twelve years. I spent a decade at InsideTracker, the main innovator when it comes to blood analytics.

And I still didn't notice that my ferritin craters every summer.

The data was never the issue. Having something that could hold all of it in working memory at the same time was.

I wrote about what happened when I pulled 12 years of Strava, 51 blood panels, and my full training log into Claude and asked it to tell me what was interesting. Here's the short version:

IRON
My ferritin craters every summer and I never noticed. Moving to Colorado dropped my average ferritin 19% permanently. Altitude forces your body to make more red blood cells, and that process drains your iron stores as a structural tax whether you're training hard or not. My best performances cluster around my highest ferritin readings. My worst effort ever; Four Pass Loop, no power on any climb; was ferritin 45, Tsat 19%. My marathon PR of 2:59 was run with ferritin 17 points below my career average. I don't know what I left on that course.

INJURY
Most predictable trigger across 8 years: a travel-related volume drop followed by a full return to normal load with no adjustment. 50 mile week → 18 mile week → back to 50. Something breaks every time. October and January are my highest injury months. The fix: never exceed 1.25x your 4-week average after a down week, no matter how good you feel.

SAUNA
331 sessions logged since 2018. Weeks with 2+ sessions correlate with a 36% lower injury signal the following week. When already dealing with something, sauna weeks resolve 35% faster. My best fitness years had the most sauna. I'm currently at 3.6% of days and my hip is flaring. Not a coincidence.

FITNESS
VO2max 63.3 at sea level. LT2 at 6:19/mi. Both tested September 2025. Controlled HR at 142 bpm while training at 5,280 feet. I'm probably in the best aerobic shape of my life and haven't had the right race to prove it.

RUNNING PARTNERS
Pulled pace and subjective feel scores across every logged run, classified by partner. Two people consistently get me to 7:44–7:49/mi on what should be easy runs; highest feel scores in the dataset. Running is measurably better when you're not doing it alone.

WEATHER
0.27 seconds per mile slower per degree Fahrenheit on road runs. Below 45°F I average 8:24/mi. Above 75°F it's 8:50/mi. November is my fastest month. June is my slowest.

All of this is the easy part. Pattern matching is becoming a commodity.

The hard part is what happens next; someone accountable who can examine you, order the follow-up test, and adjust the plan when your labs come back.

That's what I wrote about this week, and it's what @Eternal is built to be: https://t.co/Q42g2uTCaR

[Sam Tackeff 👋 @alphaprep]

HELL YES AUBRY

[Sam Tackeff 👋 @alphaprep]

@canva Shout out to the engineer who fixed this ◡̈ 👋

[Sam Tackeff 👋 @alphaprep]

There's an annoying @canva regression where emoji no longer render in PDF downloads.

Was working in early March, broken sometime before I did flyers for April. (This was one of the best things they had fixed a few years ago, and now we're back to the dark ages 😭)

[Sam Tackeff 👋 @alphaprep]

@checkpluss *or rage bait

[Sam Tackeff 👋 @alphaprep]

@checkpluss "fun"

[Sam Tackeff 👋 @alphaprep]

Intercom announces the FIN OF AN ERA #GigglesInPolyglot

[Eoghan McCabe @eoghan]

https://t.co/woWlW57HQf

[Sam Tackeff 👋 @alphaprep]

@stephsmithio Hit 50% of my city last week which is pretty fun!

[Sam Tackeff 👋 @alphaprep]

@stephsmithio CityStrides ◡̈

[Sam Tackeff 👋 @alphaprep]

@SahilBloom Running in circles in front of my house.

[Sam Tackeff 👋 @alphaprep]

@Ed_Dale @bertramfrenchie Thank you, Ed <3

[Sam Tackeff 👋 @alphaprep]

Bertram the Frenchie, age 11 and two weeks, has crossed the rainbow bridge.

He had a very nice final afternoon on a perfect sunny spring day, getting outside to porch sit in his new galaxy harness, snuggling his humans and giving lots of kisses, and most importantly voraciously eating some of his very favorite food: chicken! and cheese (some of his Trader Joe's Unexpected Cheddar Shreds.)

Known by many different names, including Bertram, Bubba, Bubba Bean, Sweet Bean, Sweet Potato, Sunpatch Boi, and Baby Bean, to name a few, Bertram was a very happy pup who really brought joy to everyone's world.

Named after his human great-grandfather, with whom he shared some personality traits, it ended up being a coincidental delight that he also shared a name with a well-loved butler character (played by Kevin Chamberlin) from the Disney TV show Jessie, much to the delight of pretty much everyone under the age of 25.

He was loved by so many, and loved us all right back.

In his vibrant life, Bertram was particularly fond of his daily walkies and his MANY many* friends around the neighborhood and around the world!

He never turned down a good treat – okay, sometimes he did, let's face it, he had high standards! – but particularly liked visiting his many shop friends on Walnut and Austin, including at Henry Bears, Dogish, AnkFit, the former Craft Beer Cellar, and the Rockland Trust Bank.

He loved the outdoors, and was happiest when grass rolling in the fields, saying hi to kiddos at the high school, sitting outside of Starbucks or on the front porch to greet the neighborhood, traipsing through the woods, on the trails at Wellesley, wading in Bulloughs pond (or the opportune deep puddle), snacking on lemony weeds, running on the beach in Rye, seeing all of his friends at the dog park, and directing us to all of his favorite buddies houses: canine, feline, and human.

Bertram was not a morning dog, but instead preferred getting cozy in one of his many beds and in front of a heater, or snuggling up directly so that his snoozles could appropriately hit the Zoom microphone. He enjoyed lounging in the "leg canoe". He loved having visitors over so he could let them pat him for as long as they wanted.

He never missed a good warmth opportunity, and in his later years, was fond of letting you know that it was sun patch (or fire bed) time, and "we really should *all* be in the other room right now."

Unsurprisingly, on that note, Bertram had a very strong point of view about pretty much everything. (A family trait!)

Bertram was not a toy obsessed dog, although he did have a few favorites as a puppy, including his pig, and his hedgehogs, and was a big fan of a bully stick.

Not one to destroy a toy or rip anything to shreds, he had one notable exception early in life where he went to town on an LL Bean Wicked Good Slipper. Just couldn't control himself! But would you blame him?

He very much enjoyed practicing his tricks skills, including sitting, shake, and spin, and was a skilled communicator, particularly by tapping a person (or the refrigerator) with his paw to let people know his ardent desires.

One of his earliest tricks was as an escape artist: managing at mere months old to parkour over a gate, or unlatch a double latched crate! Fortunately he was never one to wander away, as he much preferred the company of his people to traveling solo. (And would always make sure his whole traveling party was together - no pup left behind!)

One of his most important jobs was surveying the neighborhood from his ottoman at the window, and was known to many at night as the bat-dog, where his silhouette was formidable and the comfort to many.

He was a very big fan of the small humans in his life. Waving to him daily was part of our small human neighbor's nightly bed time routine, and he loved going over to play with his littlest buddies. He was also a fan of FaceTime with his littlest friends all over the world.

He deeply loved his family, and was the love of our lives.

Like so many of our loved ones, Bertram lived life until the fullest until the very end, where he was diagnosed suddenly with fast-moving cancer on his last day. Dogs make us better people, and while he had a truly great run at life, it never feels like enough.

Bertram is joining his many friends over the rainbow bridge, including his human grandfather, Matt, for some spareribs and many skritches in the great beyond.

In lieu of traditional condolences, Bertram would have very much liked you to go out and treat yourself to a little ice cream or snackie, so please do that in his honor!

[Sam Tackeff 👋 @alphaprep]

@maiab sorry for this curse 😅 🤣

[Sam Tackeff 👋 @alphaprep]

@canva Ah thank you! Would love if you could keep me posted ◡̈ will send special vibes to whoever is working on this fix!

[Sam Tackeff 👋 @alphaprep]

@jerryjamesstone I think 2010 Earthquake Twitter was my favorite Twitter

[Sam Tackeff 👋 @alphaprep]

@0xgaut @lessin Guy next to me at the start line of a 50k trail race was wearing them 🤣

[Sam Tackeff 👋 @alphaprep]

Okay looks like it’s Tassel and includes a suite of ticketing, and all sorts of graduation ops.

[Sam Tackeff 👋 @alphaprep]

At a Northeastern graduation and *very curious* how much this AI name announcement software costs. They train the names but it’s definitely hit or miss.

The part that is super odd is that if it matches some naming pattern the AI “accent” tries to match native speaker?

[Sam Tackeff 👋 @alphaprep]

@canva Broke sometime between Feb 23rd and March 23d!

[Sam Tackeff 👋 @alphaprep]

@canva The problem is upon pdf download. PNG downloads of same image are supporting. But the PDFs strip.