MyFit.care — The manifesto · 2026 edition

Born from the needs of McArdle patients.

Mainstream health apps overlook rare metabolic diseases. We started with them: the second wind protocol, pre-exercise carbohydrate loading, the emergency card to hand to clinicians. Then we opened the tool up to everyone — nutrition, sport, sleep, connected watch — with the same rigour.

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13 conditions referenced 47 CIQUAL/ANSES nutrients 6 languages Garmin sync 10 s
Emergency — McArdle disease

GSD-V · ICD-10 E74.04 · OMIM #232600

Avoid: succinylcholine, volatile agents, statins

Anaesthesia: TIVA propofol + remifentanil + rocuronium

myfit.care

Wallet format — fold it and keep it with you

The founding artefact: the McArdle emergency card,
printable for free

Chapter 01 — The problem

Living with a rare condition

For most people, a health app is for counting calories. For someone living with McArdle disease, the first ten minutes of a brisk walk can mean the difference between a muscle contracture — and an ordinary day.

This type V glycogen storage disease prevents muscle from using its glycogen during exercise. It upends how you eat before, during and after exertion — and no mainstream app took that into account. Starting too hard, too fast is the classic trap: pain, contracture, and in severe cases rhabdomyolysis, the muscle breakdown that can land you in the emergency department.

MyFit.care was born of this observation, told in detail on our about page: start with the most demanding case, solve it properly, and only then generalise. The “second wind” protocol, managing the pre-exercise carbohydrate load, tracking rhabdomyolysis episodes: these features do not exist out of marketing opportunism, but because patients needed them — a need documented in the publications of associations such as AFG France, AGSD UK and IamGSD.

The most tangible proof of this mission fits on a piece of paper: the McArdle emergency card, a free printable document listing the contraindicated drugs and the anaesthesia protocol to hand to clinicians. Because in hospital, facing a team that has never heard of the disease, a folded sheet in a wallet can change the course of your care.

First door

I want to track my health every day

Nutrition, sport, sleep, hydration, goals. Sync your watch and stay on track, simply — ad-free, with a serious CIQUAL/ANSES nutrition database.

Get started for free →
Second door

I live with a condition

Specialised tracking, AI insights, symptom journal and export for your doctor. Reinforced support, informed by protocols published by patient associations.

See the conditions covered →
Chapter 02 — The science

What the literature documents

The founding phenomenon is called the second wind. After six to ten minutes of moderate-intensity exercise, a McArdle patient's heart rate drops sharply and exercise suddenly becomes easier: fatty acids and blood glucose take over from the failing muscle glycogen.

60 100 140 bpm 0 6 min 10 min 14 min −30 to 40 bpm SECOND WIND
Figure 1 — Heart rate during aerobic exercise in McArdle disease (schematic tracing). After the initial rise, the shaded zone (6–10 min) marks the second wind: HR drops by 30 to 40 bpm and exertion becomes tolerable. Source: adapted from Vissing & Haller, N Engl J Med 2003; 349:2503-9.

This is not a coaching trick — it is published physiology. And it has immediate practical consequences: a mandatory gradual warm-up, carbohydrate intake before exercise following published guidance, and vigilance for warning signs. Everything the app automates.

“After six to ten minutes of exercise, heart rate drops and exercise suddenly becomes easier.”
adapted from Vissing & Haller — N Engl J Med 2003
“Regular aerobic training improves exercise capacity, provided you start gently and respect the second wind.”
adapted from the 2014 Cochrane review (exercise and McArdle disease)

Where our guidance comes from

Every piece of guidance shown in the app is attached to a level of source, and presented as educational information to discuss with your care team — never as a diagnosis or a prescription.

  • ATrials and systematic reviews. Vissing & Haller protocol (NEJM 2003), 2014 Cochrane review, international consensus statements (Battelino 2019 for time in range).
  • BGuidelines from learned societies and care networks. FILNEMUS, ESC/EAS for dyslipidaemias, EULAR for fibromyalgia.
  • CExpert opinion and patient associations. IamGSD, AFG France, AGSD UK, AMMi — including the emergency card protocols.
  • DContinuous co-construction. Feedback from patients and specialist clinicians, integrated version after version.
Table 1 — The 13 conditions referenced in MyFit.care, with ICD-10 codes. Six have in-depth guidance today; co-construction with patients is ongoing.
Condition Family ICD-10 Monitoring markers Factsheet
McArdle disease (GSD-V) Glycogen storage E74.04 Second wind, pre-exercise sucrose, creatine, CK Read
Von Gierke disease (GSD-I) Glycogen storage E74.01 Cornstarch, fructose/galactose-free diet, night alarms Read
Pompe disease (GSD-II) Glycogen storage E74.02 ERT, respiratory function, 6MWT, FVC Read
Cori-Forbes disease (GSD-III) Glycogen storage E74.03 Fractionated meals, blood glucose, CK Read
Tarui disease (GSD-VII) Glycogen storage E74.09 No second wind, paradoxical carbohydrates Read
Type 1 diabetes Metabolic E10 Bolus calc, CGM, AGP, time in range Read
Type 2 diabetes Metabolic E11 HbA1c, GLP-1, post-meal walking Read
Obesity Metabolic E66 GLP-1 (Wegovy, Mounjaro), bariatric surgery Read
Cholesterol / dyslipidaemia Metabolic E78 LDL/HDL, SCORE2 score, statin alert if McArdle Read
Fibromyalgia Muscle M79.7 VAS, FIQR, FSS, sleep and HRV Read
Myopathy Muscle G71–G72 MMT-8, MFM-32, CK Read
Muscular dystrophy Muscle G71.0 Duchenne, Becker, FSHD, LGMD · NSAA Read
Hidradenitis suppurativa (Verneuil) Dermatologic L73.2 Body mapping, Hurley stage, adalimumab Read
Table 2 — Going further: the site's expert factsheets and articles, by condition.
Topic Key references Link
McArdle second wind: how many minutes? Vissing & Haller, NEJM 2003 Read the article
Dangerous medications in McArdle IamGSD, AMMi protocols Read the article
Time in range & T1D bolus calc Battelino 2019 consensus View the factsheet
Type 2 diabetes: metformin, GLP-1, SGLT2i HbA1c targets 2026 View the factsheet
Pompe disease: ERT & respiratory monitoring Myozyme, Nexviazyme, Pombiliti View the factsheet
Hidradenitis suppurativa (Verneuil) Hurley stages, adalimumab View the factsheet
Fibromyalgia: pain, fatigue, sleep EULAR 2017 View the factsheet
Obesity: Wegovy, Mounjaro, bariatrics Semaglutide, tirzepatide View the factsheet
Cholesterol: LDL, HDL, SCORE2 score ESC/EAS 2026 View the factsheet

All medical blog articles · The full detail of the 13 referenced conditions

Chapter 03 — The tool

A toolkit, not a gadget

Every feature answers a need documented in the previous chapters. Here is the essence, presented as in a laboratory notebook: one figure, one caption, one use.

Tracked nutrientExample guidance value
Pre-exercise carbohydrates (McArdle)30–40 g, 30 min before
Food glycaemic indexGI < 50 preferred (T2D)
CIQUAL/ANSES micronutrients47 parameters
Sodium (sweat protocol)individual profile, D-3 → D+1
Figure 2 — Nutrition as clinical data: CIQUAL/ANSES database, glycaemic index, condition-specific targets. Source: CIQUAL nutrition table, ANSES; OpenFoodFacts product database.
3.1 — Nutrition

Forty-seven nutrients, not just calories

Calorie counting is ground zero of tracking. MyFit.care builds on the ANSES CIQUAL database (47 nutrients) — vitamins, minerals, fatty acids — complemented by OpenFoodFacts barcode scanning and AI photo analysis of meals.

  • Personalised targets per condition (pre-exercise carbohydrates, GSD-I fructose/galactose-free diet, low-GI for T2D)
  • Plate photo: food identification and portion estimation
  • Hydration & sweat protocol: sweat test, sodium profile, D-3 to D+1 plan, 50+ electrolyte products
  • Weight and body composition tracking (Garmin Index BIA)
3.2 — Ketogenic

Keto tracking, down to the medical constraint

A standard tracker adds up total carbs. On keto, the figure that matters is net carbs — carbs minus fibre. MyFit.care computes it from the CIQUAL database, applies your diet's ceiling and tracks ketone levels.

  • Net carbs against your diet's ceiling (25 g strict, 30 g targeted), not a generic value
  • Actual daily split as a percentage of calories, against the diet's target
  • Blood ketones (BHB), electrolytes raised for ketosis, recipes filtered on real macros
  • McArdle pre-exercise carbs tracked separately, never charged to the keto budget

Explore keto tracking

SECOND WIND 07:24 ❤ 112 bpm · in zone 30–40 g carbs taken ✓
Figure 3 — The GlycoGuard watch face during exercise: elapsed time in the adaptation window, target heart zone, carbohydrate reminder. Source: Garmin Connect IQ GlycoGuard app, included with a MyFit.care account.
3.2 — Watch & sensors

The wrist as a measuring instrument

Garmin Glycoguard streams heart rate, SpO2, stress and Body Battery every ten seconds during exercise, with automatic second wind detection for McArdle patients. Pairing uses a six-digit code; each watch gets a dedicated key (HMAC-SHA256 signed messages, revocable).

  • FIT/TCX/GPX file import and Garmin Index data (body composition)
  • Sleep, HRV, respiration, skin temperature
  • Continuous glucose monitors Dexcom G7 and FreeStyle Libre
  • Apple Watch, Samsung Galaxy Watch and Wear OS: in development, honestly announced
MyFit Assistant McArdle specialist

Hello! I've analyzed your data. Your pre-exercise carb intake is optimal. Your walking sessions show a faster second wind than before.

I suggest: creatine monohydrate 3-5g/day, 2.5L minimum hydration on activity days, and 30-40g carbs 30min before exercise.

Conversation mock-up — the assistant knows your data and answers in plain language, without replacing medical advice.

3.3 — AI insights

A coach that reads your file, not an oracle

Each condition has a dedicated agent that cross-references nutrition, activity, sleep, symptoms and treatments. Trend analysis highlights combinations of factors to watch — educational information to discuss with your care team; it does not predict any medical event.

  • 24/7 conversational coach, aware of your data
  • Analysis of photographed medical reports (value extraction)
  • Drug and supplement interaction checking
  • Weekly PDF reports, shareable with the care team
Hurley II flare 03/26 scar
Figure 4 — Interactive anatomy: locate symptoms and lesions on a 3D body (here, Verneuil mapping with Hurley stages). Source: MyFit.care body-mapping module (Hurley staging I/II/III).
3.4 — Symptoms & anatomy

Show, rather than re-explain

The symptom journal records intensity and triggers; 3D anatomy lets you locate them precisely. For hidradenitis suppurativa, body mapping tracks lesion evolution and Hurley stage — so you arrive at consultations with a visual history, not approximate memories.

  • Symptom journal with intensity, triggers and patterns
  • Lab results tracked over time (CK, HbA1c, TSH…)
  • Medication tracking: dosage, reminders, adherence, stock alerts
  • Recovery score (HRV, sleep, Body Battery)
{
  "resourceType": "Observation",
  "code": { "coding": [{
    "system": "http://loinc.org",
    "code": "2157-6",
    "display": "Creatine kinase"
  }]},
  "valueQuantity": { "value": 842, "unit": "U/L" },
  "subject": { "reference": "Patient/mcardle-01" },
  "context": { "coding": [{
    "system": "http://hl7.org/fhir/icd-10",
    "code": "E74.04"
  }]}
}
Figure 5 — An interoperable medical export: FHIR HL7, LOINC codes for observations, ICD-10 for conditions. Source: illustrative example of a FHIR resource; real export available in the app (professional plan).
3.5 — Clinician space

Data your doctor can actually read

The professional portal gives the doctor a synthetic view of the patient: lab history, symptom frequency, exercise patterns, McArdle-specific CK, second wind success rate. The FHIR HL7 / LOINC / ICD-10 export integrates with EMR/EHR records.

  • PDF, CSV, FHIR exports and API for third-party integrations
  • Emergency medical QR code (conditions, treatments, allergies)
  • Premium features, professional plan

Also useful for other situations

The same instruments serve beyond the 13 referenced conditions: heart disease, chronic fatigue (ME/CFS), IBD, sleep apnoea, thyroid disorders, kidney failure, mitochondrial diseases, POTS and dysautonomia, lupus and autoimmune diseases, Ehlers-Danlos, psoriasis and eczema, endometriosis, epilepsy, spondyloarthritis — as well as weight loss and classic sports tracking. Twelve more conditions are announced for 2026–2027 (POTS, Ehlers-Danlos, lupus, endometriosis, IBD, sleep apnoea, migraines, RA, SpA, Hashimoto's, PCOS, IBS).

Chapter 04 — The human evidence

Tools, but above all people

An app cures no one. What it can do is make a consultation clearer, a night calmer, a walk possible. That is what we are building for the patient community.

A word from the founder

“MyFit.care was born of a simple observation: mainstream health apps almost entirely ignore the metabolic specificities of rare diseases. We started with McArdle disease, building on what its associations and clinicians have published. Every major product decision is checked against what that community describes and publishes. It is slower. It is also the only honest way to do it.”

Matthieu Roland Founder — Cryptaguard SRL, Belgium

Up against the other apps, in all honesty

Most apps track nutrition or activity. MyFit.care goes further: condition tracking, AI insights and data encryption.

Table 3 — Comparison based on the publishers' public information (May 2026). Trademarks cited belong to their respective owners.
Feature MyFit.care
Recommended		 MyFitnessPal Yazio Garmin Connect
Detailed nutrition tracking ✓✓✓~
ANSES / CIQUAL database (47 micronutrients) ✓✕✕✕
Food glycemic index ✓✕~✕
Watch & connected device sync ✓✓✓✓
CGM glucose sensors (Dexcom, FreeStyle) ✓✕✕✕
Chronic condition tracking (13) ✓✕✕✕
McArdle / second wind protocols ✓✕✕✕
AI insights (trends, interactions) ✓✕✕✕
Conversational AI coach ✓✕✕✕
Medication tracking + interactions ✓✕✕✕
Clinician space / doctor sharing ✓✕✕✕
Medical export FHIR / HL7 ✓✕✕✕
Sessions & Garmin files hosted in France (OVH) ✓✕✕✕
GDPR compliant ✓~✓~
Free version (freemium) ✓✓✓✓
Ad-free ✓✕~✓

✓ Included · ~ Partial or limited · ✕ Not available — Comparison based on the publishers' public information (May 2026). Trademarks cited belong to their respective owners.

Colophon — Sources & communities

MyFit.care draws on the published work of patient associations and care networks: AFM-Téléthon, FILNEMUS, AFG France, AGSD UK, IamGSD, EUROMAC, FFD diabète and FibromyalgieSOS. Their public protocols — notably the emergency cards — directly inspired the app. These organisations are neither partners nor endorsers of MyFit.care: full credit for that work is theirs.

Chapter 05 — Get started

Verifiable guarantees

No inflated promises: a free app, a single €3/month plan for AI, and a legal framework stated in full.

  • Free, no credit cardThe whole app stays free — nutrition, exercise, symptoms, journal, Garmin, exports. Only the AI features require the Mini plan at €3/month.
  • One-click cancellationFrom the settings, no email or justification required. Your data stays exportable for free, at any time, as PDF, CSV or FHIR.
  • Association members −50%Members of a patient association get half off the Mini subscription, on simple proof of membership.
  • A clear legal frameworkMyFit.care is a tracking tool, not a medical device within the meaning of the MDR regulation. Encrypted data (AES-256), GDPR-compliant processing, HDS certification on the roadmap — see data security and privacy policy.

Key concepts, explained simply

Second wind

The second wind is a phenomenon specific to McArdle disease: after 6 to 10 minutes of moderate-intensity exercise, heart rate drops and exercise suddenly becomes easier, thanks to fatty acids and blood glucose taking over as fuel.

Glycogen storage disease type V (GSD-V)

Glycogen storage disease type V, also known as McArdle disease, is a rare metabolic disorder caused by a deficiency in myophosphorylase, the enzyme that releases glucose stored in muscle glycogen.

FHIR / HL7 export

FHIR HL7 is an international standard for exchanging health data. MyFit.care exports your data with LOINC and ICD-10 codes so it can be integrated into your doctor's medical records.

Health-data protection

Data encrypted in transit (TLS 1.3) with an encrypted local cache (AES-256-GCM). Sessions and Garmin files hosted in France (OVH); certified HDS hosting is on our roadmap.

Continuous glucose monitor (CGM)

A CGM sensor measures blood glucose levels in real time, day and night. MyFit.care is compatible with Dexcom G7 and Abbott FreeStyle Libre sensors.

Body Battery & HRV

Body Battery and heart rate variability (HRV) are recovery indicators measured by Garmin watches. MyFit.care syncs them to compute your recovery score.

Frequently Asked Questions

Epilogue

Start with ten minutes. The rest will follow.

Create an account, sync your watch, log a meal. All the tracking is free; only the AI costs €3 a month.

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