Frequently Asked Questions

Does SleepAnalytics work with Garmin watches?

Yes. If you use Garmin Connect on iPhone and have enabled Apple Health sync, SleepAnalytics automatically reads your Garmin sleep and workout data through Apple Health. No extra setup needed — if your data is in Apple Health, SleepAnalytics can use it. Garmin syncs sleep duration and HR; detailed sleep stages depend on your Garmin model and the data it sends to Apple Health.

Does SleepAnalytics work without Apple Watch?

It works with any sleep data available in Apple Health (iPhone motion-based tracking, Garmin, or other third-party apps), but Apple Watch Series 4+ provides the most detailed stage data (Core, Deep, REM, Awake). Without a wearable, you'll see Sleep/Wake metrics and most score components, but not granular stage analysis.

How accurate are the sleep stages?

Apple Watch's sleep staging has a mean kappa of 0.63 in Apple's validation dataset — fair to moderate agreement with PSG. Sleep sensitivity is ~97.9% and wake specificity is ~75%. The app presents stages as estimates and does not claim medical-grade accuracy. We always recommend interpreting trends, not individual nights in isolation.

What is the difference from the Apple Health app?

Apple Health shows basic sleep data and a simple Sleep Score (watchOS 10+) based on duration, consistency, and interruptions. SleepAnalytics adds: hypnogram visualization, 8-component Sleep Score, exercise correlation, Sleep Regularity Index, Social Jet Lag, HRV tracking, ODI, Sleep Debt, and 90+ day trend analysis.

Why does my sleep score vary so much night to night?

Sleep is inherently variable. HRV fluctuates based on stress, illness, alcohol, and exercise. Deep sleep percentages vary by how much physical recovery you need. Consistent sleep times help stabilize your score — which is why the Regularity component exists. Look at 7-day and 30-day trends, not individual nights.

Does sleep tracking drain my Apple Watch battery?

Apple Watch sleep tracking uses the built-in sleep mode that Apple has optimized. Most users with 30%+ battery at bedtime have enough charge for a full night. Series 4 and later should manage fine with normal daily charging habits.

Can SleepAnalytics detect sleep apnea?

No. SleepAnalytics is not a medical device and cannot diagnose sleep apnea. If you have Apple Watch Series 9 or later (watchOS 11), you may receive Apple's own sleep apnea notifications (FDA-cleared for screening, not diagnosis). If you suspect sleep apnea, consult a doctor for a proper sleep study (polysomnography).

What is "Sleep Efficiency" and what's a good score?

Sleep Efficiency (SE) = Total Sleep Time ÷ Time in Bed × 100. It measures how much of your time in bed you actually spend asleep. According to NSF clinical guidelines (Ohayon et al. 2017): >90% is excellent, 85–90% is good, and <80% may indicate sleep difficulties and warrants attention.

What is WASO?

WASO stands for Wake After Sleep Onset — the total time you spend awake after first falling asleep and before your final awakening. Normal is ≤20 minutes. More than 40 minutes is clinically considered poor sleep quality (Ohayon et al. 2017). Common causes include stress, alcohol, caffeine, and sleep apnea.

What is Social Jet Lag?

Social Jet Lag is the difference between your mid-sleep time on work/school days vs. free days. If you sleep at midnight on weekdays but 3am on weekends, you have 3 hours of social jet lag. Research (Wittmann et al. 2006) shows that ≥2 hours of SJL is associated with health risks including metabolic syndrome, depression, and higher BMI.

What is the Sleep Regularity Index (SRI)?

SRI measures the consistency of your sleep/wake patterns over time. It compares your sleep state (asleep or awake) at each time of day to the same time the previous day. Scores range from 0–100; population median is ~60. SRI ≥75 indicates good regularity. Research (Windred et al. 2024, eLife) found that irregular sleepers (SRI <41) have a 53% higher all-cause mortality risk.

How many nights do I need before I see patterns?

Basic metrics start after your first night. SRI needs 7 consecutive nights. Exercise correlation analysis requires at least 14 matched nights (14 workouts + 14 following sleep sessions) before patterns reach statistical significance. HRV baseline takes 14–30 nights to stabilize into a meaningful personal baseline.

Does it work for naps?

Yes. SleepAnalytics processes any sleep session detected in HealthKit, including naps. Short sessions (<2 hours) are labeled as naps and tracked separately in the History view. Nap TST counts toward your daily total but not your nighttime efficiency score, keeping your nightly metrics accurate.

Is my data shared with anyone?

No. All data processing happens on your device. We have no servers that receive health data. We use no advertising networks, analytics platforms, or third-party SDKs that access health data. See our Privacy page for full technical details.

What Apple Watch model do I need?

• Basic sleep/wake tracking: Apple Watch Series 1+
• Detailed sleep stages (Core/Deep/REM): Series 4+
• Blood Oxygen (SpO2): Series 6+
• Wrist Temperature: Series 8, Ultra, SE (3rd gen)+
• Breathing Disturbances: Series 9, Ultra 2, SE (3rd gen)+

How do I set up Sleep Focus for best results?

1. Go to iPhone Settings → Focus → Sleep
2. Enable "Track Sleep with Apple Watch"
3. Charge your watch to at least 30% before bed
4. Keep wrist detection turned on

The more consistently you wear your watch during sleep, the better the data quality and the more accurate your patterns will become over time.

Can I suggest new features or request support for my device?

Absolutely — we read every message. Email features@analyticszone.app with your request. Include your device, what you'd like to track, and why it matters to you. Feature requests directly influence the roadmap. Popular requests (like Garmin support) are prioritized based on community demand.