Sync Fitbit health data to the local cache.

Fetches data from the Fitbit API and stores it in SQLite for fast offline queries. Run this before using other fitbit_get_* tools.

Syncs incrementally: only fetches data newer than the most recent entry in each table. First sync fetches the specified number of days.

Args: data_types: What to sync. Options: "all", "heart_rate", "activity", "exercises", "sleep", "weight", "spo2", "hrv". Comma-separated for multiple, e.g. "sleep,hrv". Default: "all". days: Days of history for first sync (default: 30). Ignored on subsequent syncs (uses last synced date).

Returns summary of records synced per data type. Not for querying data - use fitbit_get_heart_rate, fitbit_get_activity, fitbit_get_sleep, etc. instead.

Get daily resting heart rate and heart rate zones.

Returns resting HR and zone breakdown (Out of Range, Fat Burn, Cardio, Peak) from the local cache by default, auto-syncing if stale. Use live=True to bypass the cache entirely.

Args: start_date: Start date as "YYYY-MM-DD", "YYYY-MM", or "30d". Default: last 30 days. end_date: End date as "YYYY-MM-DD". Default: today. live: If true, fetch directly from Fitbit API instead of cache.

Returns one entry per day with resting_hr and zones array. Zone data: name, minutes, caloriesOut, max/min HR for each zone.

Get daily activity summaries (steps, calories, active minutes, distance).

Returns data from the local cache by default. Use live=True to fetch from Fitbit API. Run fitbit_sync first to populate the cache.

Note: live=True fetches one API call per day - avoid large ranges to stay within the 150 requests/hour rate limit.

Args: start_date: Start date as "YYYY-MM-DD", "YYYY-MM", or "30d". Default: last 30 days. end_date: End date as "YYYY-MM-DD". Default: today. live: If true, fetch directly from Fitbit API instead of cache.

Returns one entry per day with steps, calories, active minutes, distance. active_minutes = very_active + fairly_active (excludes lightly active).

Get exercise log entries (individual tracked activities).

Returns exercise sessions from the local cache by default. Use live=True to fetch from Fitbit API. Run fitbit_sync first to populate the cache.

Args: start_date: Start date as "YYYY-MM-DD", "YYYY-MM", or "30d". Default: last 30 days. end_date: End date as "YYYY-MM-DD". Default: today. exercise_type: Filter by activity name (case-insensitive substring match), e.g. "cycling", "walk", "run". Default: all types. live: If true, fetch directly from Fitbit API instead of cache.

Returns exercise entries with name, duration, calories, avg heart rate, distance, and source (auto-detect vs manual). Note: HR data from cycling may be unreliable (optical sensor vs handlebar grip).

Get nightly sleep data (duration, stages, efficiency).

Returns sleep data from the local cache by default. Use live=True to fetch from Fitbit API. Run fitbit_sync first to populate the cache.

Sleep data is sparse: only nights with watch-tracked sleep are present. Travel, off-wrist nights, or manual logs may be missing.

Args: start_date: Start date as "YYYY-MM-DD", "YYYY-MM", or "30d". Default: last 30 days. end_date: End date as "YYYY-MM-DD". Default: today. live: If true, fetch directly from Fitbit API instead of cache.

Returns one entry per night with total_minutes, efficiency, start/end times, and stage breakdown (deep, light, REM, wake minutes).

Get weight log entries (weight, BMI, body fat percentage).

Returns data from the local cache by default. Use live=True to fetch from Fitbit API. Run fitbit_sync first to populate the cache.

Weight data is sparse: only days with weigh-in entries are present.

Args: start_date: Start date as "YYYY-MM-DD", "YYYY-MM", or "30d". Default: last 30 days. end_date: End date as "YYYY-MM-DD". Default: today. live: If true, fetch directly from Fitbit API instead of cache.

Returns one entry per weigh-in with weight_kg, bmi, fat_pct.

Get nightly SpO2 (blood oxygen saturation) data.

Returns data from the local cache by default. Use live=True to fetch from Fitbit API. Run fitbit_sync first to populate the cache.

SpO2 data is sparse: only nights with on-wrist sleep tracking produce readings. Requires Fitbit Premium for access to this endpoint.

Args: start_date: Start date as "YYYY-MM-DD", "YYYY-MM", or "30d". Default: last 30 days. end_date: End date as "YYYY-MM-DD". Default: today. live: If true, fetch directly from Fitbit API instead of cache.

Returns one entry per night with avg, min, max SpO2 percentage. Normal range: 95-100%. Below 90% may indicate sleep apnea.

Get nightly HRV (heart rate variability) data.

Returns data from the local cache by default. Use live=True to fetch from Fitbit API. Run fitbit_sync first to populate the cache.

HRV data is sparse: only nights with on-wrist sleep tracking produce readings. Requires Fitbit Premium for access to this endpoint.

Args: start_date: Start date as "YYYY-MM-DD", "YYYY-MM", or "30d". Default: last 30 days. end_date: End date as "YYYY-MM-DD". Default: today. live: If true, fetch directly from Fitbit API instead of cache.

Returns one entry per night with daily_rmssd and deep_rmssd (ms). RMSSD = root mean square of successive RR interval differences. Higher values generally indicate better recovery and parasympathetic activity.

Analyse trends in cached Fitbit data.

Computes averages and totals over time from the local cache, auto-syncing if stale.

Args: data_type: What to analyse. Options: "heart_rate", "activity", "exercises", "sleep", "weight", "spo2", "hrv". Default: "activity". period: Aggregation period. Options: "weekly", "monthly", "quarterly". Default: "monthly". start_date: Start date as "YYYY-MM-DD" or "365d". Default: last 12 months. end_date: End date as "YYYY-MM-DD". Default: today. compare: Compare two periods. Format: "last_30d vs previous_30d", "2026-03 vs 2026-02", "2026-Q1 vs 2025-Q4". When set, period/start_date/end_date are ignored.

Returns aggregated averages per period. For activity: steps, distance, active minutes. For exercises: sessions, duration, calories. For sleep: duration, efficiency, stage breakdown. For heart_rate: resting HR min/avg/max. For weight: weight, fat%, BMI. For spo2: avg/min/max oxygen saturation. For hrv: daily and deep RMSSD. Not for raw data - use fitbit_get_* tools instead.