I measured my sleep with Garmin and BrainBit, and here is what I learned

Anastasiia Ku
3 min readSep 10, 2024

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Understanding sleep has always been of a great interest to me, and modern wearable technology offers rather in-depth insights. I decided to measure my sleep with the Garmin Vivosmart 5 wristband and the BrainBit Mindo headband— which approach sleep measurement from very different angles — and see whether their measurements align.

BrainBit Mindo [left] and Garmin Vivosmart 5 [right]

Garmin Sleep Stages

The Garmin Vivosmart 5 is a wristband tracker designed to monitor various aspects of health and activity, including heart rate, stress, oxygen levels, and sleep.

It measures sleep using a combination of movement data and heart rate variability. It tracks periods of inactivity and subtle changes in your heart rate to estimate when you’re awake, in light sleep, deep sleep, or REM sleep. It also uses pulse oximeter data to monitor blood oxygen levels, so that it contributes to the final analysis of sleep patterns during the night.

Garmin sleep stages analysis

In my Garmin sleep report above, I got the report about all four key stages of sleep:

  • Light Sleep: The dominant stage, indicating the body is resting but not yet in a deeply restorative phase.
  • Deep Sleep: The stage when the body repairs and restores itself.
  • REM Sleep: The phase crucial for brain function and emotional processing.
  • Awakenings: The amount of time of restlessness and sleep interruptions.

BrainBit Brainwaves Activity

BrainBit Mindo is an EEG headband designed to monitor brainwave activity, providing insights into mental states like relaxation, focus, and sleep quality.

It measures sleep by tracking brainwave activity using EEG (electroencephalography) sensors. It monitors 3 brainwave frequencies: Theta (deep relaxation), Alpha (relaxation), and Beta (concentration). And in such a way it displays a person’s mental state during different sleep stages.

This approach provides a more direct measure of brain activity, focusing on the mental aspect of sleep rather than physical metrics.

BrainBit Theta, Alpha and Beta waves activity

With my initial hypothesis, BrainBit’s brainwave patterns would correlate Garmin’s Deep sleep with increase in Theta waves, and REM and Awakening with increase in Beta waves.

It was very interesting to see that the same night sleep report from BrainBit showed the following brainwave patterns throughout my sleep:

  • Theta Waves: High activity during the first half of the night that indicates deep relaxation, which correlated well with Garmin’s deep sleep stages.
  • Alpha Waves: Was present in moderate amounts throughout the sleep, suggesting periods of calm and relaxation.
  • Beta Waves: Spikes in Beta activity during brief periods could indicate moments of alertness, which also align with Garmin’s recorded wakefulness and REM sleep.

Correlations Between the Devices

What I found really interesting is how the data from both devices compare to each other side by side:

Comparison of BrainBit brainwaves activity and Garmin sleep stages
  • Deep Sleep and Theta Waves: Garmin’s deep sleep stages align with BrainBit’s Theta waves, indicating periods of physical restoration and deep mental relaxation.
  • REM Sleep and Beta Waves: REM sleep phases, where the brain is more active, correspond with increased Beta wave activity, reflecting heightened brain function during dream states.
  • Awakenings and Beta Waves: The brief awake periods noted by Garmin are mirrored by spikes in Beta waves, showing moments of alertness.

Conclusion

Both Garmin and BrainBit offer valuable insights into the sleep process, each from a different perspective. Garmin provides a clear breakdown of sleep stages, while BrainBit captures the mental activity associated with those stages. Together, they offer a more complete understanding of sleep quality, highlighting both physical rest and mental recovery. I was quite surprised how well the data from both devices match, almost by the minute!

What should I measure next — let me know in the comments section?

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