Applies to: Sleep Number® app, SleepIQ® account
The Heart Rate Variability (HRV) feature in the Sleep Number® app shows how well your body recovers overnight. Your Sleep Number® smart bed measures HRV automatically while you sleep using its full‑body sensor. Higher HRV typically means better recovery and energy; lower HRV may indicate stress, illness, overexertion, or inconsistent sleep.
You can view daily, weekly, and monthly HRV insights in the Biosignals section of the Sleep tab.
What Is Heart Rate Variability (HRV)?
Heart Rate Variability (HRV) is the variation in time between each heartbeat. This variation reflects how adaptable and recovered your body is.
In general:
- Higher HRV → better recovery, relaxation, energy, and resilience
- Lower HRV → reduced recovery, stress, fatigue, or potential illness
HRV is one of the clearest indicators of overnight recovery, which is why Sleep Number® measures it while you sleep—when external factors are minimized.
How the Sleep Number® Smart Bed Measures HRV
Your smart bed uses its full‑body sensor to detect your biosignals each night.
It calculates HRV using:
SDNN (Standard Deviation of Normal‑to‑Normal intervals)
- This is a widely used measure that reflects the average variability between heartbeats, measured in milliseconds.
Why HRV measurement during sleep is best
- No movement or activity interference
- More stable physiological conditions
- More accurate recovery assessment
Your HRV range is unique to you, influenced by:
- Age
- Sex
- Health
- Fitness
- Stress levels
- Daily routines
Tracking HRV over time helps you understand your personal baseline.
What Your Heart Rate Variability Score Means
High HRV (more variability)
Indicates:
- Strong overnight recovery
- High energy potential
- Relaxation
- Better physical and cognitive performance
- Nervous system balance
This means your body is adapting well and is prepared for activity.
Low HRV (less variability)
Often indicates:
- Reduced recovery
- Lower daytime energy
- Fatigue
- Higher stress load
- Potential illness
- Impact from overexertion
- Inconsistent sleep
Low HRV may be temporary — daily lifestyle factors can have a major impact.
What Impacts Heart Rate Variability?
Factors that improve HRV
- Getting enough sleep
- A consistent sleep schedule (same bedtime & wake time daily)
- Light or moderate exercise (e.g., walking, yoga)
- Relaxing wind‑down activities (meditation, journaling, warm bath)
Factors that reduce HRV
- Poor or insufficient sleep
- Inconsistent sleep patterns
- Over-exertion or strenuous exercise without recovery
- Working or using screens too close to bedtime
- Illness
- Stress
- Not giving yourself time to relax before sleep
How to View Heart Rate Variability in the Sleep Number® App
In the Sleep Number app (Biosignals)
Your Daily HRV appears in the Biosignals section on the Sleep tab.
You can view HRV:
- As a numerical value
- On a low-to-high scale
- With daily HRV insights
To view more details
- Open the Sleep Number app.
- Go to the Sleep tab.
- Scroll to Biosignals.
- Tap View details to see:
- Weekly trends
- Monthly changes
- Long‑term patterns
Viewing HRV in Additional Places
Wellness Report
- HRV appears in your monthly Wellness Report
- Available on the 3rd day of each month
- Requires at least 7 days of sleep data
- Shows long‑term recovery trends
SleepIQ® Website
You can also view HRV at sleepiq.sleepnumber.com:
- Log in with your Sleep Number® credentials.
- Scroll to My Biometrics.
- Select View details for weekly and monthly HRV visuals.
Frequently Asked Questions
Is HRV the same as heart rate?
No. HRV measures the variation between beats, not how fast your heart beats.
What is a “good” HRV score?
HRV is unique to each person. Instead of comparing to others, focus on your personal trends.
Why does my HRV change daily?
HRV is affected by:
- Sleep quality
- Stress
- Activity levels
- Food/alcohol
- Illness
- Time of day
Daily variation is normal. Long‑term trends are more meaningful.
Why didn’t I get an HRV value last night?
Possible reasons:
- Very short sleep session
- Excessive movement
- Sleeping off the bed
- Sensor interference
Does HRV affect my SleepIQ® score?
No. HRV is separate from SleepIQ® scoring.
Can I improve my HRV?
Yes. Behaviors that support recovery—consistent sleep, relaxation, moderate daily movement—help increase HRV over time.