Healthier: Building Health & Fitness Businesses

Free founder playbook every Friday: https://healthierco.com

Ari Tulla is a serial health founder and angel investor. He runs Elo Health, a profitable personalised supplement company, and has spent 15 years writing small cheques into founders he believes in.

Ari thinks healthcare is the most impactful place for AI over the next five years. We talk about why the AI labs are turning to healthcare, what large language models can do with messy health data, why companies are losing money to collect that data, and where he thinks founders should build: turning data into meaning, then into a coaching layer that helps people get better.

Then Elo's story: starting a couple of years too early, why food as medicine was so hard to sell, the move to supplements and fertility, and selling through doctors who recommend the product. We also cover why a CEO's job is almost completely selling, the AI outbound playbook behind recent YC growth, the question Ari asks before committing ten years to anything, choosing a co-founder, angel investing with $5k cheques, and the personal operating system (a colour-coded calendar and meeting-free Wednesdays) behind a big life.

Disclosure: Will is an investor in Elo Health.

CHAPTERS

00:00 AI's bad sales pitch

00:20 Intro

01:49 Welcome to Healthier

02:27 Ari's path into health

06:01 Go all in on the new AI tools

07:13 Why healthcare is AI's most impactful arena

08:34 What LLMs can do with messy health data

10:31 Why companies lose money to collect your data

11:07 Will's AI health experiment

12:59 A medical team of one

14:12 Who wins: big tech, model companies or startups?

16:35 How fast the world is changing

18:55 How Elo pivoted

21:50 Food as medicine

23:13 Why customers wouldn't do the finger prick

24:02 Getting CAC and LTV right

24:33 Starting a couple of years too early

25:24 Healthier Notes

25:53 Why Elo moved to supplements

27:30 Fertility, and doctors who recommend

29:39 Make it their idea

30:31 A CEO's job is almost completely selling

31:21 Increase your surface area of luck

32:57 The AI outbound playbook behind YC growth

35:21 The ten-year question

36:41 The decisions that shape a life

38:36 Choosing a co-founder

40:25 The 100-question co-founder test

42:22 Lessons from angel investing

44:56 $30k set aside, $5k cheques

46:12 Why second-time founders win

47:19 Often the first money in

48:00 Ari's personal operating system

49:59 The colour-coded calendar

51:21 Meeting-free Wednesdays

54:47 Who can we trust in health?

Elo Health: https://elo.health

Luminary Vitamins: https://www.luminaryvitamins.com

Ari Tulla: https://www.aritulla.com

Healthier Notes, a founder's playbook every Friday: https://healthierco.com

Healthier is the show for founders in health, fitness and wellness. Subscribe for more.

Andrew Steele won an Olympic medal for Team GB, then built Stride, a preventative health membership with almost 16,000 paying customers in 65 countries.

Stride hit a £4m run rate within three months of launch, bootstrapped, mostly selling DNA tests that nobody can buy twice. We talk about how Andrew went back and worked out why people were really buying, the three jobs customers hire Stride for, the GLP-1 programme nobody wanted, why going direct to consumer first made gyms, resorts and employers easier to sell to later, how he has mixed bootstrapping with VC and non-dilutive funding, and how an £800-a-year membership is heading for 85% renewals.

Disclosure: Will is an investor in Stride and a StrideOne member.

CHAPTERS

00:00 Cold open

01:16 Welcome to Healthier

01:37 What Stride is

02:44 16,000 customers in 65 countries

03:31 Selling whatever was ready

05:12 A £4m run rate in three months

05:31 You can't sell a second DNA test

06:26 Demand with no outlet

07:28 Talk to customers, or trust your instinct

09:14 What the consultation data showed

10:06 Healthier Note

10:31 Three jobs customers hire Stride for

12:48 Why "live forever" is a farce

14:00 Health as identity

16:47 Health optimisation has been hijacked

18:29 One better decision at a time

19:28 How Stride chose its product mix

22:18 The GLP-1 programme nobody bought

24:49 Why consumer first

27:12 Practitioners, gyms, resorts, then employers

29:10 How D2C data helps B2B partners

30:17 Bootstrap first, then raise

31:37 Commodity blood tests plus AI

32:26 The most ambitious research study in human health

34:40 Explaining the value is the bottleneck

37:02 85% renewals on an £800 membership

38:43 Where to find Stride

Stride: https://www.getstride.com/

Andrew's essay, What happened? Stride happened: https://huper.substack.com/p/what-happened-stride-happened

Healthier Notes, a founder's playbook every Friday: https://healthierco.com

Healthier is the show for founders in health, fitness and wellness. Subscribe for more.

Nicola Telford runs Tabu Ventures, an angel community backing health businesses most investors find too awkward to look at: sexual wellness, women's health, addiction and recovery, and death.

We talk about why culture accepts these markets before capital does, what the founders who break through have in common, and what she learned about taking money. That includes why there's never free money, how to fit-check an investor before you take their cheque, and the problems Tabu wants founders to work on next.

CHAPTERS

00:00 Cold open

01:11 Welcome to Healthier

01:47 What Tabu Ventures is

02:57 The four taboo categories

05:05 Why these categories suit angel investors

06:18 Culture accepts it before capital does

08:45 Early signs capital is catching up

12:19 Healthier Note

13:08 What breakthrough founders have in common

15:30 Why a personal connection keeps founders going

18:54 Rebuilding your motivation after a company closes

22:35 There is never free money

24:50 Bad money and how to fit-check investors

26:32 How syndicates work with founders

29:10 Who invests with Tabu

30:40 How to be a useful angel investor

32:38 Tabu's request for startups

34:40 Addiction businesses with many front doors

35:56 Screen time, NoFap apps and the hype curve

39:13 Who Tabu wants to hear from

Tabu Ventures: https://tabu.ventures/

Taboo + The Hype Cycle: https://tabu.ventures/insights/taboo-and-the-hype-cycle/

Pitch Tabu: https://tabu.ventures/pitch/

Healthier Notes, a founder's playbook every Friday: https://healthierco.com

Healthier is the show for founders in health, fitness and wellness. Subscribe for more.

Iain de Havilland, founder of NADclinic, joins Will Read to discuss building a business that supplies other providers, developing local partnerships and finding opportunities beyond your home market. Explore why Iain chose infrastructure as his route to scale, how practical clinics helped demonstrate products, and what founders can learn from adapting technology used in another industry. Join the Healthier Note for lessons, playbooks and events for founders in health, fitness and well-being: https://healthierco.com Find NADclinic: https://nadclinic.com

How do you keep gym members coming back when they are free to leave? Evgenia Koroleva, founder of ONE LDN, joins Will Read to explain the choices behind a community-led fitness business — from flexible memberships and focused positioning to brand partnerships and new revenue streams.

Evgenia shares how the gym measures community through attendance, retention and referrals; why Nike approached ONE LDN; and how she decides which ideas are worth testing. She also describes three years of approximately 30% year-on-year growth, rebuilding after COVID and planning the next locations.

Practical ideas for founders building gyms, membership businesses and other companies in health, fitness and wellbeing.

CHAPTERS

00:00 How to build a thriving gym

00:44 Meet Evgenia Koroleva, founder of ONE LDN

04:00 Making community a measurable revenue engine

07:25 Choosing who your gym is for

10:43 Why ONE LDN rejected long-term contracts

12:38 Testing pricing, memberships and new ideas

14:49 Spotting trends without chasing every fad

17:21 Finding new revenue in your existing space

20:48 Weighing the cost of recovery facilities

22:28 Keeping your offer simple

23:09 How partnerships led Nike to ONE LDN

26:40 The customer bigger gym brands overlook

28:40 Bootstrapping, rebuilding and deciding to expand

31:03 Three years of growth and the case for expansion

32:03 Choosing locations using customer demand

32:57 Founder resilience and celebrating wins

ONE LDN: https://www.oneldn.com/

More episodes: https://www.healthstacks.ai/episodes

Subscribe to Healthier for more conversations with people building in health, fitness and wellbeing.

Growth and performance figures are reported by the guest.

“Don’t get into hardware if you don’t like being punched in the face 10 times a day.” Stefan van der Fluit has spent six years building FLOWBIO, a wearable that turns sweat into data about sodium and fluid loss for endurance athletes.

He joins Will to explain how childhood dehydration and an attempt to earn a professional IRONMAN card led to the product; why the hard parts of hardware can become a defensible moat; how FLOWBIO shifted from a DTC-first plan to a business where 65% of sales come through retail partners; and why its strategy alongside much larger wearable companies is to go an inch wide and a mile deep.

They also cover authentic athlete relationships, the Tour de France “Spot the Bulge” idea, creating more surface area for luck, leading with humility, and the difference between creating value and capturing it.

Disclosure: Will Read is an investor in FLOWBIO.

FLOWBIO: https://flowbio.com/

Max Cotton fought MMA professionally, then spent five years building Vor, an AI exercise programming engine that deliberately avoids LLMs. He tells Will about the founder who spent $40,000 in tokens on an LLM that produced the same workout every time, how PureGym founder Peter Roberts came to join the board and fill the round, the two pivots that took Vor from consumer coaching to B2B infrastructure, and why starting a company tested him more than cage fighting and ultramarathons combined.

Hamish Grierson, co-founder and CEO of Thriva, gives a screen-share tour of how the UK blood-testing company turns your results into action.

We go through Compass (three tests a year, chosen for you based on your goals and history), how Thriva benchmarks your markers against people your own age and sex rather than a sick population, and the difference between being "in range" and actually being optimal.

Then Hamish shows the Healthspan dashboard — blood data sitting alongside Oura, Garmin and Whoop in one view — and demos the new Thriva Health Assistant live, fielding a cholesterol question and an Omega-3 dinner query with full longitudinal context.

This is what happens when a purpose-built AI has your actual blood history, not just the test you paste in.

Timestamps

00:00 Cold open

00:32 Why Hamish co-founded Thriva

02:10 The problem with standard blood test ranges

04:05 Thriva Compass: choosing your three tests a year

07:20 Live demo: reading a Thriva results dashboard

09:45 Optimal vs in-range

12:00 Healthspan dashboard: blood + wearables in one view

15:30 Why wearables without blood context miss half the picture

17:45 Introducing the Thriva Health Assistant

19:10 Demo: cholesterol question with full blood history

22:00 Demo: Omega-3 dinner query

24:15 What the Health Assistant cannot do

25:30 Wrap-up

Mike Hudack (CEO of Sling Money, former executive at Meta, Monzo and Deliveroo) built a personal health data platform almost entirely using Claude Code — connecting his whole genome sequencing, blood tests, Oura Ring, 13 years of Withings data, and workout logs into one AI system. He did it as a side project, with prompts, while running a startup and raising three kids.

In this episode, Mike walks through the exact system and how it caught something none of his individual apps could: a specific overtraining period, identified by cross-referencing HRV data with blood tests and workout logs. He also demos a food tracker he built in 10 minutes and explains why he's returning his Whoop.

LINKS & RESOURCES

- Claude Code: https://claude.ai

- Oura Ring: https://ouraring.com

- Withings: https://www.withings.com

- Strong App: https://www.strong.app

- DNAComplete.com: https://www.dnacomplete.com

- SNPedia: https://www.snpedia.com

- ElevenLabs: https://elevenlabs.io

- OpenAI API: https://openai.com

TIMESTAMPS

0:00 Introduction

1:30 Mike's background — Facebook, Deliveroo, Monzo, Sling Money

3:02 Building a food tracker in 10 minutes

3:59 AI detects overtraining from cross-referenced data

5:30 Whole genome sequencing analysis with Claude Code

8:23 Why conversational AI beats dashboards

9:46 Claude vs ChatGPT as your doctor

11:00 Layering data: Oura, Withings (13+ years), Strong app

13:30 The FatSecret problem — £1,500/month for UK access

15:00 MCP server architecture

16:50 Why Mike is returning his Whoop

18:00 WhatsApp-based health AI via Open Claude

19:24 "Most exciting thing in the last hundred years"

20:30 Proactive daily health summaries

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ABOUT HEALTHSTACKS

AI workflows for training, nutrition, and recovery you can steal today.

Hosts: Will Read & James Grant

Website: https://healthstacks.ai

Subscribe for new episodes every Wednesday

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#HealthStacks #AIHealth #ClaudeCode #OuraRing #Whoop #GenomicData #HealthData #PersonalAI

James McAulay connected his Garmin, Strava, TrainingPeaks, gym app, and a 65-page blood work report into a single AI coaching system inside Claude Desktop — no code required. He runs four live demos showing exactly how it works.

The system critiques recent runs using sleep and HRV data, designs structured workouts based on readiness metrics, spots gaps in gym programming, and personalises post-workout nutrition from specific blood markers.

What you'll learn:
- How to connect multiple health data sources to one AI agent using MCP servers
- A system prompt structure that gives AI enough context to actually coach you
- How to turn blood work into personalised, actionable nutrition guidance
- The honest limitations — what AI coaching can and cannot replace

Resources: www.healthstacks.ai/episodes/ep3-james-mcaulay