Shindo Shindo is a training and wellness tool, not a medical device. It does not diagnose, treat, or prevent any condition, and nothing it shows you is medical advice — if you have a health concern, talk to a qualified professional rather than to an app.
Everything below expands on that one sentence. Please read it before you let Shindo influence how you train or eat.
1. What Shindo actually is#
Shindo reads recovery and training data from your wearables (Apple Health, and optionally Garmin), runs it through deterministic algorithms on your device, and presents the results as a daily readiness picture, a training plan, and nutrition targets. A generative AI model writes the explanatory text around those numbers.
It is a tool for making better-informed training decisions. It is not, and is not intended to be, a substitute for a physician, a physiotherapist, a registered dietitian, or a qualified coach.
2. Not a medical device#
- Shindo is not a medical device and has not been evaluated, certified, cleared, or approved by any medical regulator — not the FDA, not under the EU Medical Device Regulation (CE/MDR), not by any equivalent body anywhere.
- It does not diagnose, treat, cure, mitigate, or prevent any disease, injury, or condition.
- No output of the app — no score, no flag, no chart, no AI-written sentence — constitutes a medical opinion, a clinical measurement, or a diagnosis.
- Do not use Shindo to decide whether to seek, delay, change, or stop medical care. If something in the app worries you, that is a reason to contact a professional, not a reason to self-manage.
3. Every number is an estimate, not a clinical measurement#
Shindo computes a lot. All of it is algorithmic estimation from consumer wearable data, and all of it inherits the error of the device that recorded it. Specifically, the app estimates and models:
- Readiness and its drivers — from heart-rate variability (HRV, measured as SDNN by your device), resting heart rate, sleep, and current training form, each compared against a personal baseline built from your own history.
- Training load — TSS, and the CTL / ATL / TSB (fitness / fatigue / form) balance, plus aerobic decoupling and efficiency factor.
- Periodization — training phases, an 80/20 intensity distribution target, and a weekly load-ramp cap.
- Energy availability (EA) and an under-fuelling flag informed by the RED-S literature (see §5).
- Body-fat percentage, estimated from sex, age and BMI using the Deurenberg (1991) population regression whenever no direct measurement is available. This is a population formula applied to one person — it is explicitly labelled as an estimate in the app, and it can be substantially wrong for a lean, muscular, or otherwise atypical athlete.
- VO₂max, estimated from your own resting and maximum heart rate and/or your fitted critical speed, when no measured value has been ingested.
- Critical power (CP) and W′, and critical speed (CS) and D′, fitted from your own recorded power and pace efforts.
- Race predictions for 5 km, 10 km, half marathon, and marathon, derived from that critical-speed fit.
- Load-risk monitoring — Foster monotony and strain, and Gabbett acute:chronic workload ratio (ACWR) zones.
- Early-warning signals — change-point detection in resting heart rate and HRV, and statistical anomaly flags across HRV, RHR, respiration rate, SpO₂, and body temperature.
- Forecasts — projected form over the coming days, and trajectory toward a goal event.
- Thresholds and training zones, fitted from your own workout history rather than from a generic formula.
- Calorie and macronutrient budgets, including estimated maintenance energy expenditure.
Accuracy is bounded by:
- the source device — Apple Watch, Garmin, or whatever else you wear. Optical heart-rate sensors, sleep staging, SpO₂ and respiration estimates all have known and sometimes large error margins, especially during motion and at the extremes.
- how you wear it — fit, placement, skin tone, tattoos, temperature, and motion all affect optical measurements.
- how complete your data is — Shindo deliberately shows nothing rather than guessing when data is missing, but sparse history still makes every fitted model less reliable.
Where the app itself labels a value as an estimate (the body-fat figure and the VO₂max fallback are the clearest cases), treat it as a rough indication only.
4. Forecasts are models, not promises#
The form forecast, the trajectory toward your goal event, and the 5K / 10K / half-marathon / marathon predictions are projections from mathematical models fitted to your past data. They assume you keep training roughly as planned, stay healthy, and race in reasonable conditions. They cannot account for illness, heat, altitude, terrain, sleep debt, life stress, or luck.
Do not treat a predicted race time as a target you owe yourself, and do not treat a favourable forecast as permission to ignore how you feel.
5. Energy availability and the RED-S signal#
Shindo estimates energy availability — roughly, the energy left over for your body’s basic functions after training is paid for — and shows it on a Low / Watch / Normal scale. The thresholds come from published work on Relative Energy Deficiency in Sport (RED-S).
This is a wellness signal, not a diagnosis. A “Low” reading does not mean you have RED-S, or any other condition. It means the app’s estimate, from the food you logged and the training you did, fell below a threshold worth paying attention to.
RED-S is a clinical picture that only a qualified professional can assess, and it has consequences for bone health, hormonal function, and long-term performance. If your energy availability is repeatedly low, treat it as a prompt to speak to a sports physician or registered dietitian — not as something to solve inside the app.
Wherever the app, its subscription screen or its store listing mentions RED-S, the term refers to the published research the thresholds are taken from — never to a finding, a risk score, or a conclusion about you. Shindo does not assess you for RED-S and cannot.
6. Food, weight, and eating disorders#
Shindo calculates calorie budgets, shows macronutrient targets, surfaces energy deficits, tracks body weight and body composition, and estimates energy availability. For many athletes this is a useful set of numbers. For some people it is not.
If you live with — or have lived with — an eating disorder, disordered eating, or a difficult relationship with food, weight, or your body, these features carry real risk of making things worse. Daily calorie targets, visible deficits, weight trends, and body-fat estimates are precisely the kind of numbers that can pull an old pattern back into the foreground.
This is not a judgement, and it is not a reason to feel excluded from training well. It is a straightforward caution: please consider whether these features are good for you right now. You can use Shindo for training and recovery without logging food. And if food, weight, or exercise has felt compulsive or distressing, please talk to a doctor, a therapist, or a registered dietitian with eating-disorder experience — a professional who can see you is worth more than any app, and Shindo is not equipped to help with this.
If you are in distress, please reach out to a local eating-disorder helpline or your healthcare provider.
7. Talk to a doctor first#
Please seek medical advice before starting a training programme, or before substantially increasing your training load, and in particular if any of the following apply:
- You experience chest pain or pressure, dizziness, fainting, palpitations or an irregular heartbeat, or unusual shortness of breath — during exercise or at rest. Stop exercising and seek medical attention; do not wait to see what the app says tomorrow.
- You have, or suspect you have, a cardiovascular, respiratory, or metabolic condition — including heart disease, hypertension, arrhythmia, asthma, or diabetes.
- You are pregnant, recently postpartum, or trying to conceive.
- You are recovering from illness, injury, or surgery.
- You take medication that affects heart rate or heart-rate variability — beta blockers most obviously, but also some antiarrhythmics, antidepressants, thyroid medication, stimulants, and others. These drugs alter the very signals Shindo’s readiness model is built on. With them, resting heart rate, HRV, and every readiness number derived from them can be uninformative or actively misleading, and the app has no way to detect or correct for this.
- You are under 16 years old — Shindo is not intended for minors, and the Terms of Use set 16 as the minimum age of use (higher where your national law requires it).
8. AI-written text can be wrong#
Shindo’s numbers are computed by deterministic algorithms on your device. The words around them — the morning report, the plan rationale, the nudges — are written by a generative AI model (Google Gemini), which interprets those numbers into readable coaching language.
Generative models make mistakes. They can phrase something poorly, overstate a trend, miss context you would consider obvious, or produce text that reads as more confident than the underlying data justifies.
The numbers in the cards are the source of truth. The prose around them is not. If the text and the data seem to disagree, trust the data — and trust your own judgement over both. The same applies to food photo estimation: nutritional values inferred from a photograph are approximations, not measurements — and when you keep such an entry, that approximation is what Shindo counts in your daily totals and writes back to Apple Health. Edit an entry you think is wrong before relying on it.
9. You decide how you train#
Shindo advises. You decide. Every training decision — to go hard, to go easy, to rest, to race, to stop mid-session — is yours, and you carry the responsibility for it.
Your body outranks your readiness score. A green day does not oblige you to train, and an amber one does not forbid it. Pain, unusual fatigue, illness, and injury are information the app cannot see. Listen to them.
10. Not for emergencies#
Shindo does not monitor you in real time, does not detect medical emergencies, and cannot summon help. It is not a fall detector, not a cardiac monitor, and not a safety device.
In an emergency, call your local emergency number or go to the nearest emergency department.
11. Limitation of liability#
To the fullest extent permitted by applicable law, Aleksandr Kolesnikov provides Shindo on an “as is” basis and is not liable for injury, illness, loss, or damage arising from your reliance on the app’s outputs. Nothing in this disclaimer excludes or limits liability that cannot lawfully be excluded or limited. Full terms are in the Terms of Use.
12. Questions#
If anything here is unclear, or you think the app told you something it should not have, please tell us — we take that seriously.
- Email: [email protected]
- Support page: /support
- Aleksandr Kolesnikov, Dimitri Nikolaou 7, Limassol, Cyprus, 4006
See also: Privacy Policy · Terms of Use · Cookie Notice · Support