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Fitbit Sleep Log Data Export Format

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The Fitbit data export contains information from participants' Fitbit sleep activity, including:

  • Sleep Log Summary - A high-level summary of each participant's daily sleep patterns.
  • Sleep Log Details - A detailed breakdown of sleep data. Each entry contains information for a particular participant and time period, indicating whether the participant was awake or asleep, and their quality of sleep. The detailed log also tracks short periods (<= 3 minutes) of wakefulness, which may overlap with other sleep periods.

In the CSV export, the summary and details will be found in two separate data files. In the JSON export, they are combined.

The data in the Fitbit export is obtained through the Fitbit API. The available data will vary based on the device capabilities and the user's privacy settings. See the Fitbit "Get Sleep Log" documentation for more information about using and interpreting Fitbit data.

Table of Contents

Sleep Log Summary

Field Description
Duration Sleep duration, in milliseconds.
Efficiency A gauge of sleep efficiency.
EndDate

The end date of the time period, in ISO 8601 format.
InfoCode Numeric code corresponding to the Type value.
LogId The unique identifier in Fitbit’s system for the activity log
record.
MinutesAfterWakeup Minutes it took the user to get out of bed after waking.
MinutesAsleep Minutes the user spent asleep.
MinutesAwake Minutes the user spent awake.
MinutesToFallAsleep Minutes it took the user to fall asleep.
ParticipantID The stable, automatically generated, internal system identifier for this participant. Universally unique identifier (UUID).
ParticipantIdentifier The MyDataHelps Designer identifier of the participant associated with the Fitbit user. Can be used to cross reference with Participants.
SleepLevelAsleep Minutes spent asleep, when the data type is "classic."
SleepLevelAwake Minutes spent awake, when the data type is "classic."
SleepLevelDeep Minutes spent in deep sleep, when the data type is "stages."
SleepLevelLight Minutes spent in light sleep, when the data type is "stages."
SleepLevelRem Minutes spent in REM sleep, when the data type is "stages."
SleepLevelRestless Minutes spent in restless sleep, when the data type is "classic."
SleepLevelWake Minutes spent awake, when the data type is "stages."
StartDate The start date of the time period, in ISO 8601 format. 
TimeInBed Minutes the user spent in bed.
Type

Fitbit provides two kinds of sleep data:

  • stages - Reports data with 30-second granularity, and grades sleep as deep, light, REM, or wake.
  • classic - Reports data with 60-second granularity, and grades sleep as asleep, restless, or awake.

Sleep Log Details

Field Description
EndDate The ending date/time of the log entry, in ISO 8601 format.
LogId The unique identifier in Fitbit’s system for the activity log
record.
ParticipantID The stable, automatically generated, internal system identifier for this participant. Universally unique identifier (UUID).
ParticipantIdentifier The MyDataHelps Designer identifier of the participant associated with the Fitbit user. Can be used to cross reference with Participants.
SleepLogDate The date the sleep log was updated, in ISO 8601 format.
StartDate The start date/time of the log entry, in ISO 8601 format.
Type

The type of log:

  • SleepLevel log entries represent times when the user was either: (a) asleep, or (b) awake for more than 3 minutes.
  • ShortSleepLevel log entries represent short periods (<= 3 minutes) of wakefulness. These time periods may overlap with the SleepLevel entries.
Value The type of sleep recorded (e.g., wake, deep, light, or REM).

Sample CSV Export

In the CSV export, the summary and details are in separate files.

Sleep Log Summary:

ParticipantIdentifier,StartDate,EndDate,Duration,Efficiency,InfoCode,MinutesAfterWakeup,MinutesAsleep,MinutesAwake,MinutesToFallAsleep,TimeInBed,Type,SleepLevelAwake,SleepLevelAsleep,SleepLevelDeep,SleepLevelLight,SleepLevelRem,SleepLevelRestless,SleepLevelWake
aaaa-bbbb-cccc-dddd,2020-03-24T23:08:30,2020-03-25T08:14:00,32700000,87,0,0,456,89,0,545,stages,,,103,237,116,,89
aaaa-bbbb-cccc-dddd,2020-03-27T23:08:00,2020-03-28T03:34:00,15960000,88,0,4,217,49,0,266,stages,,,37,141,39,,49
1111-2222-3333-4444,2020-04-22T23:13:00,2020-04-23T01:39:30,8760000,86,2,0,126,20,0,146,classic,3,126,,,,17,

Sleep Log Details:

ParticipantIdentifier,SleepLogDate,Type,StartDate,EndDate,Value
aaaa-bbbb-cccc-dddd,2020-04-01T05:52:30,ShortSleepLevel,2020-03-31T22:56:00.0000000+00:00,2020-03-31T22:57:00,wake
aaaa-bbbb-cccc-dddd,2020-04-01T05:52:30,SleepLevel,2020-04-01T03:16:00.0000000+00:00,2020-04-01T03:18:00,light
1111-2222-3333-4444,2019-05-12T08:41:30,ShortSleepLevel,2019-05-12T02:23:00.0000000+00:00,2019-05-12T02:24:00,wake
1111-2222-3333-4444,2020-04-01T05:52:30,SleepLevel,2020-04-01T05:02:30.0000000+00:00,2020-04-01T05:34:00,rem

Sample JSON Export

In the JSON export, the summary and details are in the same file.

{
    "ParticipantIdentifier": "aaaa-bbbb-cccc-dddd",
    "StartDate": "2020-04-02T22:11:30",
    "EndDate": "2020-04-03T06:43:00",
    "Duration": "30660000",
    "Efficiency": "95",
    "InfoCode": "0",
    "MinutesAfterWakeup": "0",
    "MinutesAsleep": "443",
    "MinutesAwake": "68",
    "MinutesToFallAsleep": "0",
    "TimeInBed": "511",
    "Type": "stages",
    "SleepLevelAwake": null,
    "SleepLevelAsleep": null,
    "SleepLevelDeep": "73",
    "SleepLevelLight": "332",
    "SleepLevelRem": "38",
    "SleepLevelRestless": null,
    "SleepLevelWake": "68",
    "SleepLogDetails": [
        {
            "Type": "SleepLevel",
            "StartDate": "2020-04-03T21:46:00",
            "EndDate": "2020-04-03T22:14:00",
            "Value": "wake"
        },
        {
            "Type": "SleepLevel",
            "StartDate": "2020-04-03T22:14:00",
            "EndDate": "2020-04-03T22:39:00",
            "Value": "light"
        },
        {
            "Type": "ShortSleepLevel",
            "StartDate": "2020-04-04T06:40:30",
            "EndDate": "2020-04-04T06:41:00",
            "Value": "wake"
        }
    ]
}

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