Shindo - What it is
- An endurance-coaching app for iPhone — running, cycling, swimming, strength and triathlon
- Platform
- iPhone, iOS 26.4 or later. No Android, iPad, Mac or web version
- Data source
- Apple Health — any watch, strap or app that writes to it
- Account needed
- None. No sign-up, no cloud account, data stored on the device
- Price
- Free to download. Shindo Pro is $12.99/month or $109.99/year on the US storefront
- Free tier
- Readiness, plan, workout detail, widgets and Apple Health sync, for the most recent 60 days
This page answers what people ask before installing Shindo. If you already have the app and something is not working, the support centre is the better starting point — it covers troubleshooting, permissions and how to reach a person.
What Shindo is
What is Shindo?
Shindo is an endurance-coaching app for iPhone. It reads your recovery and training data from Apple Health, computes a daily readiness score and your training load on the device itself, builds a weekly training plan, and gives you one decision each morning: what to train today, and why. It covers running, cycling, swimming, strength work and triathlon.
Who is Shindo for?
Endurance athletes training for a goal — a marathon, a half, a triathlon, a gran fondo — who already wear something that records sleep and heart rate, and who want the numbers interpreted rather than just displayed. It assumes you train several times a week and care why a session is prescribed. It is not a couch-to-5K app and not a general fitness tracker.
Is Shindo a medical device?
No. Shindo is a training tool. Every score, flag and forecast is an estimate computed from wearable data — not a clinical measurement and not a diagnosis. It does not diagnose, treat, cure or prevent any disease, it does not replace professional care, and it is not for emergencies. Check with a doctor before making decisions about your health, training or nutrition.
What makes Shindo different from other readiness apps?
The numbers are computed by deterministic algorithms on your iPhone, and the AI is only allowed to put them into words. The same inputs always produce the same score, and where the AI's wording disagrees with a computed number, the number wins — that is enforced in code, not by policy. The methodology page explains exactly what is computed and how.
Data, devices and privacy
Do I need a Garmin watch to use Shindo?
No, and no other particular watch either. Shindo reads whatever your devices already write into Apple Health, so a Garmin, an Apple Watch, a Polar, a Whoop, a Coros or a chest strap paired to another app all arrive the same way. There is nothing to link and no second account to create.
Does Shindo work with an Apple Watch?
Yes. An Apple Watch writes sleep, heart-rate variability, resting heart rate and workouts into Apple Health, which is everything Shindo needs. There is no separate watch app to install — Shindo does not run on the watch, it reads what the watch already recorded.
What data does Shindo read?
Sleep, heart-rate variability, resting heart rate, workouts and the daily metrics Apple Health already holds. It writes back only the daily totals of meals you log yourself — four nutrition channels and nothing else. It never records a workout, never tracks you live, and does not use your location in the background.
Where is my data stored?
On your iPhone. There is no account, no sign-up, no cloud database of your training, and no iCloud sync — the app stores its data locally on the device. If you delete the app, that data goes with it.
Does any of my health data leave my iPhone?
Only if you switch the AI on, and only the specific numbers a piece of coaching text needs. Those requests go to our own relay, which forwards them to the language-model provider; the relay is what holds the credential, so the app itself carries no provider key. Nothing is sent for the deterministic metrics — readiness, load, plan and nutrition targets are all computed locally. The privacy policy is specific about what goes where.
Do I need to create an account?
No. Shindo has no accounts, no login, no feed, no leaderboard and no social layer. It is built for one athlete on one iPhone.
How do I delete my data?
Delete the app, and the local database goes with it. You can also revoke the Apple Health permissions at any time in the Health app, and withdraw AI or analytics consent separately in Shindo's settings — both fail closed, meaning the feature stops immediately rather than degrading quietly. The support page walks through each route.
The numbers
How is the readiness score calculated?
From your sleep, heart-rate variability, resting heart rate and the training load you are carrying, each compared against your own rolling baseline rather than a population average. The score is deterministic: the same inputs always produce the same number. Shindo shows you the four drivers behind it, so a low score always comes with a reason. The full calculation is documented here.
What are CTL, ATL and TSB?
They are fitness, fatigue and form. CTL (chronic training load) is a long exponential average of your daily training stress and stands for fitness; ATL (acute training load) is a short one and stands for fatigue; TSB (training stress balance) is CTL minus ATL and stands for form, or freshness. Shindo computes all three and charts them. There is a full guide to reading them.
Why is my readiness low when I slept well?
Because sleep is one of four drivers, not the whole score. Accumulated load, a suppressed heart-rate variability reading or an elevated resting heart rate can each pull the score down on a night you slept fine — and that is usually the useful signal, because it is the one you could not feel. This guide works through the common causes.
What is a good HRV?
There is no good absolute number — heart-rate variability varies enormously between people, and comparing your value to somebody else's tells you nothing. What matters is your own trend and how far today sits from your personal baseline, which is exactly how Shindo uses it. This guide explains what the number can and cannot tell you.
Does Shindo estimate my thresholds and training zones?
Yes, from your own training history rather than from "220 minus age". It models critical power and W' for cycling and critical speed and D' for running and swimming, and derives zones from those. This sits in the Pro tier; the underlying workout data and the zone breakdown of each individual session are free.
What happens when a metric has no data?
It stays empty. Shindo does not substitute a zero, a population average or a placeholder for a missing measurement, because a fake number is worse than an absent one — it looks like information and is not. If your watch did not record HRV last night, the driver shows as unavailable and the score is computed from what does exist.
Training plans
Does Shindo build me a training plan?
Yes, and the plan is free. Shindo builds a weekly plan with training phases, an 80/20 easy-to-hard intensity split, a capped weekly ramp and step-by-step session structure, fitted to the days you say you are available. You can reschedule, swap or skip anything by hand.
What happens if I miss a week?
The plan re-flows around it. Missed sessions are recorded honestly, your fitness and fatigue decay as they really would, and the remaining weeks are rebuilt from where you actually are rather than from where the old plan assumed you would be. There is no streak to break and no guilt-red.
What if I do a different workout than the one planned?
Shindo matches what you actually did against what was scheduled and counts the load you absorbed. A ride instead of a run, a short session instead of a long one, or a session moved to another day are recorded as a substitution, a partial or a shift — not as a failure — and the rest of the block adapts.
Can the AI write my training plan?
It can propose one, and this is the single place in Shindo where the AI does more than write text. The proposal is then checked by a validator against limits computed from your own data — the ramp cap, the easy-hard balance, your available days, your training phase, injury-risk thresholds — and if it fails any of them, Shindo publishes its own engine-built week instead. You are never shown the failure; you always get a coherent week. AI plan generation is a Pro feature, so a free athlete's plan is always the engine's.
Which sports does Shindo support?
Running, cycling, swimming and strength work, plus the triathlon combination of the first three. Training load is scored per sport, so a hard swim and a hard ride land on the same fatigue curve rather than being counted in incompatible units.
Can Shindo send workouts to my watch?
No. Shindo does not push structured workouts to a watch, and it does not record sessions. It reads what your devices recorded and tells you what to do; you execute the session however you normally would.
Nutrition
Does Shindo do nutrition?
Yes. It sets daily calorie and macronutrient targets from the training load you actually did that day rather than from a fixed diet, and you can log food and macros against them by hand for free. Logging by photo or by a sentence of description, and AI-generated meal plans, are Pro features.
Is Shindo a calorie-counting app?
Not primarily. The nutrition side exists to answer whether you are fuelling the training you are doing — it reads energy availability and carbohydrate intake against your load, which is a different question from weight loss. There is no diet plan and no weight-loss programme.
The AI
Is the AI writing my numbers?
No. Every figure you see is computed by a deterministic algorithm before the AI is called; the AI receives finished numbers and turns them into readable coaching text. If the generated text contains a number that disagrees with the computed one, the computed one is written over it automatically. The one exception is the weekly plan proposal, which is bounded by a validator — see the question above.
Can I turn the AI off?
Yes, and it is off until you turn it on. AI consent is asked separately from analytics consent during onboarding, and either can be withdrawn at any time in settings. With AI off, every deterministic feature keeps working exactly as before — you lose the written interpretation, not the numbers.
Which AI model does Shindo use?
A Google Gemini model, reached through our own relay rather than called directly from your phone, so the app ships with no provider credential in it. The specific model is configured remotely and can change; what does not change is what it is allowed to do, which is write text about numbers it was given.
Free and Pro
Is Shindo free?
The app is free to download and the free tier is not a teaser. Readiness and its drivers, today's session, the engine-built weekly plan, the plan editor, plan-to-actual matching, full workout detail, manual food logging, all eight widgets, all three Live Activity modes and Apple Health sync are free, for your most recent 60 days of history. Shindo Pro is an optional subscription.
What do I get with Shindo Pro?
Everything the language model writes for you — the morning report, the AI rebuild of your week, the journal read-out, meal plans and food logged from a photo or a sentence — plus the parts that project forward: readiness and form forecasts, a race predictor, VO2max trend and training status, your physiology model with thresholds and zones, energy availability and carbohydrate adherence, correlations across your own data, and unlimited history. Nothing in Pro changes how a number is computed: a metric reads identically whether you pay or not.
How much does Shindo Pro cost?
On the US storefront it is $12.99 a month or $109.99 a year, which is about 29% less on the annual plan. Prices differ by region and Apple can change them, so the price shown in the App Store is the authoritative one.
Is there a free trial?
New subscribers get a seven-day free trial. It is an introductory offer and eligibility is Apple's decision, per Apple ID and per subscription group — if you have already used a trial in the Shindo Pro group, you will not get another one. The free features never expire either way.
How do I cancel?
In your Apple account settings, the same way as any App Store subscription — Settings, your name, Subscriptions. Cancelling stops the renewal; you keep Pro until the period you have paid for ends, and then drop back to the free tier with your data intact.
What happens to my old data if I do not subscribe?
It stays on your device. The free tier shows your most recent 60 days; anything older is retained but not displayed until you subscribe. Nothing is deleted and nothing is uploaded.
Practicalities
Is there an Android version?
No. Shindo is iPhone-only and there is no Android version, no web app and no plan to announce for either. It is built on Apple Health, which does not exist outside Apple platforms.
Does Shindo run on iPad or Mac?
No. It is an iPhone app, in portrait, and it is not designed for iPad or Mac.
What languages is Shindo available in?
Twelve: English, Czech, German, Greek, Spanish, French, Japanese, Korean, Polish, Portuguese, Russian and Traditional Chinese. This website is English only.
How much history does Shindo need before it is useful?
It will show you something on day one, but readiness is a comparison against your own baseline, so it needs a few weeks of sleep and heart-rate data before that baseline means anything. If Apple Health already holds months of history from a watch you have been wearing, Shindo can import it and start from there.
How do I get support?
Email [email protected]. Replies are written by a person, normally within three working days and in any case within five. The support page covers the common problems first.
Still not answered?
Email [email protected]. Replies come from a person, normally within three working days. If you would rather just try it, Shindo is on the App Store and the free tier needs no card.