Apps like Strava
Great at recording and sharing · then tomorrow is up to you
CritixFit starts every day from how you slept
Each morning your coach reads your sleep and HRV, then tells you how hard to go today
Walk · run · ride · swim · lift
A personal coach
for everyone
CritixFit plans your training, reads how rested you are every morning and talks with you any time of day · it starts from where you are
- Plans your training
- Reads how rested you are every morning
- Talks with you any time of day
- Starts from where you are
Training guidance, not medical advice · your coaches are AI
Works with
20
years of coaching
from an IRONMAN certified coach60
seconds to read your HRV
with your phone camera, no watch92
changes a pro coach made
to how your plan is built4
coaches you can call
training, body, food and mindSound familiar?
Training alone
is hard
Six things people tell us before they start · tap the ones you have felt and see what changes
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CritixFit
Answer a few questions a real coach wrote · your plan starts from where you are today
Try it below -
CritixFit
Every morning CritixFit reads how you recovered · after a bad night, your coach tells you to take it easier
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CritixFit
Four coaches in your pocket · they answer at six in the morning or at midnight
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CritixFit
Plain words · every number comes with what it means for you
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CritixFit
Tell it what hurts · the plan grows slowly and strength work supports it
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CritixFit
A community that cheers you on, challenges to join and a coach who checks in
Why CritixFit
Other apps record your workout
CritixFit coaches you
Apps like Strava
Apps like TrainingPeaks
Built for coaches · charts full of terms like
CritixFit says it in plain words
The same numbers, called what they are FitnessFatigueForm
AI chatbots
Answer one question at a time · then forget your plan, your body and your sleep
Alex remembers you
Your plan, your sleep, what hurts and what works for you, kept in one profile
Features
Everything
in one app
The real app, just as you'll use it, shown with a sample athlete's workouts
- Workout reviewLaps, charts and a map with the weather
- Race time predictorEnter one result and get your time for every distance
- Route finderRoutes that match today's workout
- Training calendarYour whole plan, day by day
- Coach chatAsk a coach anything, day or night
Your plan
Questions a real
coach wrote
In the app it takes seven short steps and about five minutes · answer a few of them here and watch the shape of your plan appear
A typical week
Get my real planA preview from the same rules the app uses · your real plan starts from your own training
Recovery · every morning
Your coach knows
how you slept
Every morning CritixFit reads your HRV, a number from your heartbeat that drops when your body is tired, and tells you how hard today should be
- Every morning CritixFit reads your HRV
- HRV comes from your heartbeat and drops when your body is tired
- Your coach tells you how hard today should be
A training guide only · not a medical device
CritixFitnow
Good morning · Alex
- Readiness
- 78
- HRV
- 68ms
- Resting heart rate
- 48bpm
The same workout, however you slept
With a watch
Your watch sends your sleep and recovery every night · there is nothing to do
Without a watch
Rest your fingertip on your phone's front camera for up to a minute · the screen lights your finger and the app reads your pulse
- 1
Rest your index fingertip on the small front camera at the top of the screen
- 2
Barely touch it · like resting on a bubble · the screen is the light
- 3
Hold still · your pulse appears in about 15 seconds and your recovery score (HRV) in under a minute
On a computer? Scan this to open the page on your phone
SAMPLE READING
72BPM
41.9Recovery (HRV)
90%Signal quality
33/36Beats
The camera reading stays on your phone · nothing is saved or sent from this page
Your watch
Which watch
do you wear?
Tap yours and watch it connect · from then on your data arrives by itself
coming soon
Pick one to connect it
CritixFit on your Garmin · our own watch app is in beta
Your coaching team
Four coaches
who know you
Alex plans your training and leads the team · Marcus looks after your body, Sofia your food and Mia your mind · they are AI coaches, there for you day and night, in seven languages
Want to ask Alex something?
Call him right from this page and ask him anything
These are recorded answers in English, in the coaches' own voices · in the app you chat with them or call them live, in seven languages
The coach behind the AI
Every plan follows
a real coach's method
Before launch, a professional triathlon coach with almost 20 years of experience and an IRONMAN certification went through the plans with us and corrected them, one rule at a time, until he approved them · his method is now built into every plan Alex writes
- A professional triathlon coach with almost 20 years of experience
- IRONMAN certified
- Before launch he corrected our plans one rule at a time, until he approved them
- His method is built into every plan Alex writes
- 20 years
- of coaching, IRONMAN certified
- 92
- changes to how plans are built
- 4 races
- half-distance triathlons the coach raced in just four months, plus a half marathon
Strength and mobility
200 exercises
each with its own video
Strength sessions are part of your plan, at home or in the gym · every move has its own short video · pick a body part, then tap any move to watch it
One plan, every sport
Run, ride, swim
or all three
Training for a triathlon? CritixFit plans all three sports in one week
Community
Train together
cheer each other on
Share your workouts with photos and videos, give kudos, comment and join monthly challenges with people at every level
- Share your workouts with photos and videos
- Give kudos and comment
- Join monthly challenges with people at every level
James just ran his first 10K · tap the heart on his post to cheer him on
AI chatbot or coach
Why not just ask
an AI chatbot?
A chatbot only knows what you type · Alex also knows your plan, how you slept last night and any pain you mentioned · here is the same question about the same person, answered both ways
Pick a question
What it knew about you
- A half triathlon in 12 weeks
- Slept badly last night
- Body not recovered this morning
- Slight Achilles pain
Alex, your CritixFit coachHe knows your plan, your night and your AchillesWhat it knew about you
- A half triathlon in 12 weeks
- Slept badly last night
- Body not recovered this morning
- Slight Achilles pain
Both answers were written by the same AI · the only difference is what it knows about you · answers are shown in English
Under the hood
Built on the best
technology of today
The same technology that runs the world's biggest apps · fast everywhere, always on and ready to grow with you
- Google Cloud
- Google Gemini
- Cloudflare
- PostgreSQL
- Redis
- three.js
- React
- TypeScript
- Node.js
- Mapbox
The thinking and the voices behind your four coaches
A global network that serves the app fast, wherever you train
The servers that write your plans and run your calls
A rock solid database, the kind banks and hospitals trust
Engineered with Claude by Anthropic
Security
Your health data
is locked tight
Your sleep, your heart and your body are personal · they are protected at every step, and only you decide what happens to them
- DDoS protection
- TLS 1.3
- AES-256
- Row level security
- Signed tokens
- Google Cloud
- Rate limits
- GDPR
- Consent first
- Invite only
While it travels
- Encrypted on the wayEvery connection uses HTTPS with TLS 1.3
- Signed login on every requestEach request is checked against your secure sign in
- Calls on short ticketsVoice calls use signed tickets that expire in minutes
Where it is stored
- Encrypted at restStored data is encrypted with AES-256
- Only you see your dataDatabase rules lock every record to its owner
- Your watch keys sealedConnections to Garmin, Strava and others are stored with AES-256-GCM
Against attacks
- Protected networkCloudflare shields the app from attacks
- Limits against abuseRate limits stop anyone flooding the service
- Watched around the clockErrors and outages are tracked the moment they happen
In your hands
- Your consent firstHealth data is only used after you say yes
- Delete it all, any timeClose your account and your data goes with it
- Never soldWe do not sell your data, to anyone
Questions we always get
Questions and answers
Still curious?Alex picks up and answers
Is it for me if I'm a beginner?
Yes · CritixFit is for anyone who wants a personal trainer's help, whether you're starting to walk or run, getting back in shape or training for a race
Do I need a smartwatch?
No · with a watch your sleep and recovery arrive on their own · without one, your phone camera reads your recovery in under a minute
How long does it take to start?
About five minutes · seven short steps a real coach wrote, then Alex builds your plan from your answers
How do I get in?
CritixFit opens to new people in small groups · leave your email at the bottom of this page and we'll write when your invite is ready
Is my coach a person or an AI?
Your coaches are AI · Alex and his three specialists · they follow the training method of a real professional coach, who reviewed and approved the plans before launch
Can't an AI chatbot build me a plan?
A chatbot writes one plan from one message · CritixFit follows a real coach's method, reads your recovery every morning and stays with you all the way to your goal
Can I really talk to Alex?
Yes · in the app you can chat with any coach or call them with your voice · on this page you can call Alex right now
Which languages do the coaches speak?
Seven · English, Spanish, Hebrew, Japanese, Korean, Dutch and Traditional Chinese · the whole app speaks them too
Which sports does it cover?
Running, cycling, swimming and triathlon, plus strength sessions · from your first walks and runs all the way to race day
What is HRV?
Heart rate variability · the tiny changes in time between your heartbeats · when it drops below your normal, your body is asking for an easier day
How does the phone camera reading work?
Rest your fingertip on the front camera for up to a minute · the screen lights your finger, and your phone works out your pulse and HRV on its own
What if something hurts?
Tell your coach · Marcus looks after aches and recovery, your plan works around it, and for pain or anything medical you are sent to a professional
Which watches and apps work with it?
Garmin, Polar, Suunto, Wahoo and Strava today, COROS soon · our own Garmin watch app is in beta
Can I keep using Strava?
Yes · connect it once and every workout you record there lands in your CritixFit plan
Is my data safe?
Yes · it is encrypted on the way and at rest, locked to your account, and you can delete everything any time
Do you sell my data?
No · we do not sell your data · the services that run CritixFit work for us under strict data agreements
Early access
Your coach is ready
when you are
CritixFit is opening to new people in small groups · leave your email and we'll write as soon as your invite is ready
Alex will be waiting for you inside
Already have an invite? Log in