All Pillars

Sleep

The foundation for recovery and cognitive performance

Overview

The Sleep Pillar quantifies your sleep quality through a weighted analysis of duration, sleep quality, and consistency. The calculation is based on recommendations from the American Academy of Sleep Medicine and the Sleep Research Society [1].

Calculation
S = 0.40 × D_norm + 0.35 × Q_norm + 0.25 × C_norm

01Weight Distribution

100%Weight
Duration40%
Quality35%
Consistency25%

Scientific Basis

Studies show that sleep quality correlates more strongly with health outcomes than sleep duration alone [2]. The weighted factors reflect current scientific findings on the relative contributions of each metric to overall wellbeing. Consistency is particularly important as irregular sleep patterns are linked to circadian rhythm disruptions [3].

The weights are based on meta-analyses and may be adjusted in future versions.

02Metrics in Detail

01

Duration

40% Weight

Total sleep time per night

Data SourceApple HealthKit / Manual Entry
UnitHours
Optimal Range7-9 hours
Normalization:D_norm = min(100, (sleep_hours / 8) × 100)
0501000h4h8hSleep Duration (hours)
02

Quality

35% Weight

Ratio of restorative sleep (deep sleep + REM) to total sleep time

Data SourceApple HealthKit (Sleep Stages)
UnitPercent
Optimal Range40-50% combined
Normalization:Q_norm = (deep_sleep% + REM%) / 0.5 × 100
0501000%25%50%Deep + REM Sleep (%)
03

Consistency

25% Weight

Standard deviation of bedtime and wake time over 7 days

Data SourceCalculated from sleep log
UnitMinutes (σ)
Optimal Range< 30 min deviation
Normalization:C_norm = max(0, 100 - (σ_time × 10))
0501000min5min10minBedtime Deviation (σ)

03Scientific References

[1]
Recommended Amount of Sleep for a Healthy AdultSleep, AASM & SRS, 2015
[2]
Sleep Duration and Quality in Relation to HealthNature Reviews Neuroscience, 2022
[3]
Circadian Rhythm Sleep DisordersSleep Medicine Reviews, 2020

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