Privacy Policy

Account Information

• Email address
• Name
• Password (stored securely via our authentication provider)

Physical and Health Information

• Date of birth and sex (used to tailor exercise selection and starting loads)
• Height and weight, including a history of bodyweight entries you log or confirm over time
• Strength benchmarks (e.g., bench press, squat, deadlift, overhead press maxes)
• Bodyweight fitness benchmarks (e.g., push-up and pull-up maxes)
• Cardio benchmarks (e.g., mile time, longest run)
• Injury information and physical limitations, and your answers about whether you've been cleared to run on an injury, and how it's feeling (Better / Same / Worse), with the dates you answered
• Menstrual-cycle information (optional, off by default): if you turn on Cycle-Aware Training in your profile, we store your opt-in, the first day of your last period, and your typical cycle length. This is sensitive reproductive-health data; we collect it only with your explicit opt-in, use it solely to time lighter training weeks, and delete all of it immediately if you turn the setting off
• Postpartum status (optional, off by default): if you turn on Postpartum Training in your profile, we store a yes/no flag plus your answers to two running-readiness questions and the dates you answered — no birth date, no medical details — used solely to program conservative, recovery-appropriate training. Like cycle data, it is sensitive reproductive-health information: collected only with your explicit opt-in and deleted immediately when you turn the setting off

Fitness Preferences

• Fitness goals
• Experience level
• Equipment access and gym type
• Preferred workout days and session length
• Cardio activities and sport-specific interests
• Exercise preferences and swap history

Usage Data

• Workout logs (exercises completed, sets, reps, weights used, rest times)
• Workout plan history and previously generated plans
• Weekly feedback responses, day-tag selections, and exercise-level feedback (loved / liked / too heavy / too light / wrong for me / hated)
• Progression and personal records data, including derived 1-rep-max estimates
• Free-text activity descriptions you enter when scheduling reserved activities (e.g., "spin class," "5K trail run")
• Self-reported session effort (RPE ratings) and daily readiness check-ins (a 1-5 energy score and, where available, a sleep-quality score derived from your watch or connected Oura Ring data)
• If you enable workout reminders, a push-notification device token and your device time zone, so reminders arrive at sensible local times

Health and Wearable Data (HealthKit)

When you use the SinewFit iOS app and grant permission, we read and write a limited set of data via Apple HealthKit:

• Heart rate samples captured by your paired Apple Watch during a workout (start, end, average, max, time-in-zone summaries)
• Workouts recorded by other apps (e.g., Apple Fitness, Strava, Peloton) — summary details only (activity type, date, duration, calories, distance, average/max heart rate, elevation) so outside activity can count toward your training week
• Sleep duration and heart-rate variability (HRV) — read on your device to ground the daily readiness check-in (e.g., "you slept 5h40 — today's plan can adapt down"). The raw sleep and HRV samples never leave your device. A few derived values can: a 1-5 sleep-quality score stored with that day's check-in, and — only if you turn on the separate "Include Apple Health and Oura sleep & readiness" setting under AI coaching — values sent to our AI provider: last night's sleep duration (and how it compares with your usual) plus a coarse readiness signal (low / normal / primed) with the daily-insight request, and, when you tap Adapt on the readiness check-in, last night's sleep duration and your morning HRV, each beside your usual, so the insight, the coach and the adapted workout can take your recovery into account (see Section 6)
• Menstrual flow (only if you turn on Cycle-Aware Training) — your recorded period days are read on your device to work out the first day of your last period and your typical cycle length. Only those two values are saved to your profile (the same two you can type in yourself); the raw menstrual-flow records never leave your device
• Body weight — recent weigh-ins so the app can suggest keeping your profile weight current (weight prescriptions depend on it). A weight is saved to your SinewFit profile only when you confirm it
• Workouts we write back to Apple Health when you complete a session — the workout summary and, for a session you tracked with GPS, its route, distance and active energy — so it appears in the Apple Fitness and Health apps alongside your other activity

HealthKit data is end-to-end encrypted by Apple and is shared only with your explicit permission via the iOS Health permission prompts. You may revoke either or both permissions at any time in Settings → Health → Data Access & Devices → SinewFit. Heart-rate summaries we display in the app and store with your workout logs are derived only from sessions that originated while the SinewFit watch app was active. SinewFit does not collect or transmit HealthKit data for any purpose other than operating the Service, and never sells, shares, or uses HealthKit data for advertising or marketing. This is a requirement of Apple's HealthKit terms, and one we honor.

Location (GPS routes)

When you track a run, walk, ride or other outdoor session with GPS — on your iPhone, on your Apple Watch, or in the browser — and allow location access, the Service records your precise location only while that session is running(iOS shows its location indicator; access is "While Using the App"). The route, distance, pace and elevation are stored with that workout in your log, and on iOS the route is written to Apple Health with the workout. We never track your location outside a session you started, never sell or share it, and never send route coordinates to our AI provider — the AI sees only the session's distance, time and pace as part of your training history. You can turn location off at any time in Settings → Privacy & Security → Location Services → SinewFit, and deleting a workout or your account deletes its route from our database.

Oura Ring Data (optional, off by default)

If you connect an Oura Ring from your profile, our servers fetch a small set of nightly summaries from Oura's cloud API (this is separate from HealthKit — Oura data comes from Oura's servers, not from your device):

• Nightly sleep duration, average overnight HRV, and lowest overnight heart rate for your main sleep period
• Daily readiness score as computed by Oura

We request only Oura's "daily summaries" permission scope — never your location, tags, sessions, or intraday heart-rate stream. These per-day values are stored in our database and used solely to ground your morning readiness check-in and — only if you turn on the sleep & readiness setting under AI coaching — the daily coaching suggestion (last night's sleep and a coarse readiness signal) and an Adapt you tap on the check-in (last night's sleep and your overnight HRV, each beside your usual), exactly like the watch-based readiness feature. We also store the OAuth access tokens needed to fetch this data; they are held server-side, are never exposed to the app or browser, and are usable only for the read-only scope you granted. Disconnecting your ring in the profile deletes the stored tokens andall synced Oura data, and you can also revoke SinewFit's access from your Oura account at any time.

AI Coach Conversations

If you use the in-app AI Coach chat feature, the messages you send and the responses generated are stored in our database so the conversation can persist across sessions. Coach messages, together with the training context described in Section 6, are sent to Anthropic's Claude API to generate replies — only after you allow AI coaching (see "Your Choice About AI" below).

AI Plan-Generation Telemetry

When the Service generates a workout plan, redesigns a day, or runs a validator pass, we store internal telemetry — the prompt sent to the AI, the raw response, validator outcomes, and timing — in a private operations table associated with your user account. This telemetry exists so we can debug bad plan generations and improve quality. It is not shared with third parties beyond the AI provider that generated the response, and is never used for advertising.

Error and Crash Reports

We use Sentry to capture application errors, exceptions, and performance issues. Error and performance reports may include your user ID, the page or feature involved (web addresses with their query strings removed), the error message and stack trace, device model, operating system version, and app version. Before a report is sent we remove query strings, request bodies, cookies and sign-in headers, and SinewFit never attaches health values (sleep, heart-rate variability, readiness, heart rate), workout weights, body measurements, injury details, AI requests, or AI Coach conversation content to a report.

Analytics and Engagement Data

We collect pseudonymous usage data — events linked to your user account, not your name — to improve the app experience. This includes which features you use (e.g., workout logging, plan generation, exercise swap), how often you use the app, and general engagement metrics. Event metadata can include fitness-profile attributes such as your selected goals, experience level, equipment access, exercise names involved in a swap, and workout ratings. Analytics events can include a coarse readiness signal (low / normal / primed) for diagnostics, but never your injury details, menstrual-cycle or postpartum information, body measurements (including sleep durations), or AI Coach conversation content.

We use Vercel Analytics to collect anonymous page view and web performance data. This data does not include personal information and cannot be used to identify individual users.