Air quality can explain why the same walk does not always feel the same.
daygauge does not measure air quality. You can log outdoor time as a habit in Quick Log and compare it with your sleep, movement and heart readings.
Start with what your own data can show.
People search air quality because pollution feels local, visible and personally relevant.
daygauge does not measure air quality or pollution exposure. It shows your movement, your sleep and your heart readings from Apple Health, so you can see what changed after days you spent outdoors.
daygauge has no air-quality data. You can log a custom habit in Quick Log, such as a walk on a poor-air day, and see it next to your sleep, movement and heart readings.
What this guide covers.
Air quality is context, not a personal verdict.
Good evidence separates what was measured from what was guessed. Your walk shows up in Apple Health movement. How much pollution you breathed in does not, and daygauge does not estimate it.
The useful question is whether days you note as poor-air days line up with shorter sleep, lower next-day movement or a softer heart-rate reading compared with your own average.
Strong signal
Sleep minutes, steps, exercise minutes, resting heart rate and HRV from Apple Health, plus a habit you log yourself.
Weak signal
A single uncomfortable day, an exact exposure dose, indoor air quality without a sensor, or any disease-risk claim.
Useful experiment
Move the same walk earlier, indoors or to a different route, log it in Quick Log and compare your readings for a week.
Boundary
No lung-health inference, no diagnosis and no treatment advice. daygauge does not measure air quality.
How the app handles this.
What this can look like in the app.
Example: on 3 days you logged an outdoor walk on a poor-air day, sleep was 39 minutes below your average.
ExampleConfidence rises when the same pattern repeats against your own baseline and drops when key signals are missing.
Try one small change, log it, then see whether the pattern repeats over the next week.
Example 1
Example: next-day steps were also lower on those days, but 3 days is too few to call it a pattern.
Example 2
Example Quest: move the walk earlier in the day for three days and compare your next readings.
Further reading.
These studies describe groups of people. They help explain the topic, but they cannot tell you what will happen to you.
- JMIR 2025 wearable personal air pollution exposure pilot
- WHO ambient air pollution factsheet
- 2025 AI framework for personalised air pollution response
Research context only. daygauge does not diagnose, treat, prevent or predict disease risk. Personal medical concerns belong with a qualified clinician.
Air quality and daygauge.
Can daygauge tell me air pollution harmed my sleep?
No. It shows your sleep next to the habits you log and how many days sit behind a pattern. It cannot say why a night was short.
Would air quality lower my Life Index?
No. The Life Index uses only your Apple Health movement, sleep and recovery readings against your own average, plus consistency and balance.
Does this need a wearable?
daygauge reads sleep and heart readings from Apple Health. A watch or wearable that writes to Apple Health gives the fullest picture.
Is precise location required?
No. Location is optional, and daygauge does not use it for air quality.
What daygauge does not do.
Related guides.
Want to compare your outdoor routine with your sleep and recovery?
daygauge is free to download. Pro is £8.99 a month or £49.99 a year.
Download on the App StorePersonal analytics, not medical advice