Updated 1 week ago Science

What is active duration in fitness tracking

Active duration measures how much time a user spends moving (active minutes) in a day. Learn how to interpret Sahha’s active_duration biomarker and use it in your product.

Active duration is the total amount of time a user spends physically active over a day. It’s typically expressed in minutes (or hours/minutes), and it answers: “How long was I moving today?” Higher active duration generally indicates more total movement time, regardless of whether that movement was concentrated in one session or spread across the day.

Key Takeaways

  • What it measures: total time spent moving (active minutes) across the day.
  • Why it matters: it’s a direct signal of daily movement volume and aligns well with public health activity guidance.
  • How to use it: drive habit goals (“30 active minutes”), streaks, and progression-based programs.
  • Best practice: pair with active hours (distribution) and intensity metrics (effort) for clearer coaching.

Metric Spec

ItemValue
Sahha field nameactive_duration
What it representsTotal time spent physically active across the day
UnitMinutes (minute)
Typical cadenceDaily (daily)
AggregationTotal (total)
Data requirementsSource-dependent; derived from phone/wearable movement detection
Best used forDaily goals, trend dashboards, habit programs, activity driver context

What Is Active Duration?

Active duration is the sum of all time windows where the user is detected as physically active.

A helpful way to think about it:

  • Active duration = “How much time did you move today?”
  • Steps = “How much movement volume did you accumulate?”
  • Active hours = “How spread out was your movement across the day?”

Example:

  • 15 min walk + 20 min gym + 10 min evening walk
    Active duration = 45 minutes

Why Active Duration Matters

Active duration is valuable because it’s:

  • intuitive: users understand “minutes active”
  • habit-friendly: it can be improved in small increments
  • program-compatible: it fits nicely into challenges and behavior change plans

From a behavior science angle, duration metrics also support “identity loops” (“I’m someone who moves daily”) when used as streaks or weekly trends, not just daily pass/fail targets.

Product takeaway: active duration is a high-signal KPI for daily movement volume that works well in goal systems and weekly progress views.

How Sahha Represents Active Duration

Sahha provides active duration as an Activity biomarker:

Biomarker: active_duration

  • Unit: minute
  • Periodicity: daily
  • Aggregation: total
  • Description: total active time per day

Example biomarker object:

{
  "name": "active_duration",
  "value": 52,
  "unit": "minute",
  "periodicity": "daily",
  "aggregation": "total"
}

Active duration can also contribute to higher-level activity-related scoring outputs (e.g., Activity Score and Wellbeing Score) alongside steps, active hours, floors climbed, and intensity signals.

How to Interpret Active Duration

Use these interpretation rules:

  • Higher than baseline: more total movement time than usual.
  • Lower than baseline: less total movement time than usual.
  • High active duration + low steps: could indicate non-step activity (cycling, gym, yoga) depending on source.
  • High steps + low active duration: could indicate short bursts of movement with low detected “active time.”

Use baselines, not rigid thresholds

Different users have different lifestyles, jobs, and constraints. A safe default is baseline framing:

  • “Compared to your usual…”

How to Use Active Duration in Your Product

1) Daily movement goals and streaks

Active duration is perfect for goals like:

  • “20 minutes active”
  • “30 minutes active”
  • “Add +10 minutes compared to your average”

Streaks work well when you allow flexibility (e.g., “5 days this week”) instead of demanding perfection.

2) Progressive habit programs

Use duration to run programs like:

  • “Start with 10 minutes/day for a week”
  • “Increase by 5 minutes each week”
  • “Maintain for consistency week”

This reduces churn compared to aggressive step goals.

3) Personalize recommendations by effort and context

Active duration can drive personalization:

  • low duration → suggest low-friction actions (short walk, movement snack)
  • stable duration but low wellbeing → look at sleep and recovery signals
  • high duration + low recovery → suggest pacing and recovery-first content

4) Explain score movement (driver cards)

Active duration is a clean explanation for activity-related score shifts:

  • “Your steps were steady, but your active duration was lower — that reduced your activity factor.”

5) Pair with distribution and intensity for better guidance

Active duration is strongest when paired with:

  • active_hours (distribution across the day)
  • steps (volume)
  • floors_climbed (bonus intensity)
  • intensity durations (low/medium/high)
  • active_energy_burned (effort proxy)

This enables guidance like:

  • “You moved for 45 minutes, but it was concentrated in one block — try adding one extra active hour tomorrow.”
  • “Duration was high and floors climbed was high — strong effort day.”

Implementation Suggestions for your Products

  1. Use active duration as a core daily KPI

    • It’s easy to understand and easy to build habit loops around.

  2. Trend it over 7–14 days

    • Weekly trends reduce noise and prevent “one bad day” discouragement.

  3. Design for source variability

    • Different platforms detect activity differently (especially for cycling, strength training, or phone-not-carried time). Handle null and edge cases gracefully.

  4. Use simple decision rules Examples:

    • If active_duration trends down → suggest “movement snack” content
    • If duration is high but active_hours is low → encourage distribution (“spread it out”)
    • If duration is high and sleep debt is rising → suggest pacing/recovery content

  5. Respect accessibility

    • Offer alternative goals and avoid framing low movement as failure.

FAQ

Is active duration the same as exercise minutes?

Not necessarily. Active duration is “time moving” and may include light movement depending on the source. Some platforms separate exercise time or moderate-to-vigorous activity; active duration is broader.

Why is my active duration low even if I did a workout?

Common reasons include device not being worn/carried, the workout type being harder to detect (e.g., strength training), or source limitations. Pair with steps, energy, or workout records when available.

Can active duration be high with low steps?

Yes. Cycling, rowing, swimming, or gym sessions can increase active duration without generating many steps (depending on device/source).

Why is my active duration missing (null)?

Active duration depends on device/source coverage and permissions. If there isn’t enough reliable activity signal, Sahha may return null. Build UI that hides or de-emphasizes the metric when unavailable.

What’s a good goal for active duration?

There isn’t a universal number. Use the user’s baseline and aim for small, sustainable improvements (e.g., +5–10 minutes/day). If your product references public guidance, do so carefully and with context.

Active duration is strongest when combined with:

  • Active Hours (distribution): active_hours
  • Steps (volume): steps
  • Floors Climbed (bonus intensity): floors_climbed
  • Active Energy Burned (effort proxy): active_energy_burned
  • Intensity durations (low/medium/high)

Notes

This content is educational and designed for product personalization and engagement. It is not medical advice and should not be used to diagnose health conditions.

References

Sahha

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