Wearable technology has come a long way from counting steps to becoming sophisticated sleep companions. Modern devices can detect sleep stages, heart rate variability, and even breathing irregularities, helping you understand the quality of your rest.

How Do Wearables Track Sleep?

Most sleep‑tracking wearables use a combination of sensors:

• Accelerometer: Detects movement to identify when you’re asleep or awake.
• Optical Heart Rate Sensor: Monitors heart rate variability (HRV) to infer REM, deep, and light sleep.
• SpO₂ Sensor: Measures blood oxygen levels, flagging potential sleep‑apnea events.
• Skin Temperature: Provides additional context for sleep quality.

What the Data Means

Understanding the metrics is key to improving your sleep hygiene.

Sleep Stage Chart

Use this visualization to spot patterns: longer deep‑sleep periods usually mean better recovery, while frequent awakenings could indicate disturbances.

Tips for Better Tracking

• Wear the device snugly but comfortably.
• Sync data each morning for accurate nightly summaries.
• Combine wearable data with a consistent bedtime routine.