Updated 1 week ago Science

What is high-intensity activity and how is it measured

High intensity activity duration measures how much time a user spends in vigorous-intensity movement in a day. Learn how to interpret Sahha’s activity_high_intensity_duration and use it in your product.

High intensity activity duration is the total time a user spends doing vigorous-intensity activity during a day (e.g., running, hard cycling, interval training). It’s measured in minutes. Higher values usually indicate more high-effort movement that can strongly improve fitness — but it can also increase recovery needs.

Key Takeaways

  • What it measures: time spent in vigorous/high-intensity activity.
  • Why it matters: high-intensity movement can drive fitness gains efficiently but needs recovery context.
  • How to use it: support performance goals, balance “push vs recover,” and personalize intensity nudges.
  • Best practice: pair with sleep/recovery signals and avoid over-coaching users into intensity.

Metric Spec

ItemValue
Sahha field nameactivity_high_intensity_duration
What it representsTotal daily time spent in high (vigorous) intensity activity
UnitMinutes (minute)
Typical cadenceDaily (daily)
AggregationTotal (total)
Data requirementsSource-dependent; classification often uses heart rate when available
Best used forPerformance programs, intensity-aware coaching, recovery pacing, activity driver context

What Is “High Intensity” Activity?

High (vigorous) intensity generally means movement that:

  • substantially elevates heart rate and breathing
  • makes conversation difficult (“talk test” fails)
  • is harder to sustain continuously

Examples:

  • running
  • hard cycling
  • HIIT / intervals
  • competitive sport

Wearables often classify vigorous activity more reliably when heart rate data is available. Treat this as an estimate.

Why It Matters

Vigorous activity can deliver strong health and performance benefits in less time, but it also increases:

  • fatigue load
  • recovery demand
  • risk of overreaching when combined with poor sleep

Product takeaway: high intensity duration is a great performance signal, but it should always be interpreted alongside recovery (sleep debt, readiness, wellbeing).

How Sahha Represents High Intensity Activity Duration

  • Biomarker: activity_high_intensity_duration
  • Unit: minute
  • Periodicity: daily
  • Aggregation: total

Example biomarker object:

{
  "name": "activity_high_intensity_duration",
  "value": 18,
  "unit": "minute",
  "periodicity": "daily",
  "aggregation": "total"
}

How to Interpret It

  • Higher than baseline: more vigorous effort than usual.
  • Low/zero: normal for many users; not everyone should (or can) do vigorous activity.
  • High intensity up + sleep/recovery down: potential “push too hard” signal (message gently).

Prefer weekly context over daily “pass/fail.”

How to Use It in Your Product

1) Performance programs (opt-in)

Examples:

  • “2 days of intervals this week”
  • “10 minutes vigorous today”
  • “Add +5 vigorous minutes/week”

2) Recovery-aware coaching

If high intensity rises while sleep debt rises or sleep quality drops:

  • reduce intensity nudges
  • suggest lighter movement / recovery content

3) Explain score movement

  • “Your vigorous activity increased — that contributed to your activity intensity factor.”

4) Safety and accessibility framing

Treat vigorous activity as optional, not required:

  • provide alternatives (moderate intensity, brisk walking)
  • avoid shaming users with low high-intensity time

Implementation Suggestions for your Products

  1. Make it opt-in

    • Many users don’t want high intensity goals; allow preference settings.

  2. Always pair with recovery

    • Use sleep debt, sleep quality, or wellbeing to prevent “overpush” messaging.

  3. Trend it

    • Weekly patterns are more informative than single-day spikes.

  4. Use simple rules

    • If high intensity spikes + sleep debt is high → suggest recovery
    • If high intensity is steady + recovery is good → reinforce progress

FAQ

Do I need high intensity activity to be healthy?

No. Many health benefits occur with moderate activity. Vigorous activity is optional and not suitable for everyone.

Why is my high intensity time missing (null)?

Intensity classification may require better sensor data (often heart rate). Some devices/sources don’t provide enough signal.

Can strength training count as high intensity?

Sometimes, but it depends on the device and how it classifies activity. Many devices under-detect strength training intensity.

  • Medium intensity duration: activity_medium_intensity_duration
  • Low intensity duration: activity_low_intensity_duration
  • Sedentary duration: activity_sedentary_duration
  • Active duration: active_duration
  • Sleep debt (recovery backlog): sleep_debt

Notes

This content is educational and designed for product personalization and engagement. It is not medical advice.

References

Sahha

General