Modern sleep trackers measure numerous metrics, but understanding what they mean and how to improve them is essential. Below are detailed guides for each key sleep metric, including ideal ranges, why they matter, and actionable steps to optimize each one.
Deep Sleep
Deep Sleep (Slow-Wave Sleep)
Deep sleep, also called slow-wave sleep (SWS) or N3 sleep, is the most restorative sleep stage. During this phase, your ...
REM Sleep
REM (Rapid Eye Movement) Sleep
REM sleep is characterized by rapid eye movements, vivid dreams, and temporary muscle paralysis. This stage is critical ...
HRV
Heart Rate Variability
Heart Rate Variability measures the variation in time between heartbeats. Higher HRV generally indicates better cardiova...
Sleep Efficiency
Sleep Efficiency Percentage
Sleep efficiency is the percentage of time in bed that you actually spend sleeping. A sleep efficiency of 90% means you ...
Sleep Latency
Sleep Onset Latency
Sleep latency is the time it takes you to fall asleep after getting into bed and attempting to sleep. It's measured from...
Resting Heart Rate
Resting Heart Rate During Sleep
Your resting heart rate during sleep reflects your cardiovascular health and recovery status. It should be at its lowest...
Awakenings
Nighttime Awakenings
Awakenings are the number of times you wake up during the night. Brief awakenings are normal, but frequent or prolonged ...
Respiratory Rate
Breathing Rate During Sleep
Your respiratory rate during sleep indicates how many breaths you take per minute while sleeping. It's a vital sign that...
Quick Reference: Ideal Ranges
| Metric | Ideal Range |
|---|---|
| Deep Sleep | 1.5-2 hours (15-25% of total sleep) for adults |
| REM Sleep | 1.5-2 hours (20-25% of total sleep) for adults |
| HRV | Highly individual - track your personal baseline. Generally, higher is better. Athletes often see 60-100ms; general population 40-60ms. |
| Sleep Efficiency | 85-95% for healthy adults. Above 95% might indicate sleep deprivation. |
| Sleep Latency | 10-20 minutes is ideal. Falling asleep instantly suggests sleep debt. |
| Resting Heart Rate | Athletes: 40-60 bpm. General population: 50-70 bpm during sleep. Look for your personal baseline. |
| Awakenings | 0-2 brief awakenings per night is normal. More than 3-4 or prolonged awakenings indicate fragmented sleep. |
| Respiratory Rate | 12-20 breaths per minute during sleep. Lower end is generally better. Watch for deviations from your baseline. |