A Comprehensive Review of Sleep Quality Analytics Derived by Using Wearable Data to Correlate Mattress Material Density with Rapid Eye Movement (REM) Duration

Sleep quality plays a vital role in physical, emotional, and cognitive health, with REM (Rapid Eye Movement) sleep being a particularly critical phase associated with memory consolidation, learning, and emotional regulation. While multiple factors influence sleep architecture, the effect of mattress material—especially its density—has not been deeply explored in terms of its impact on specific sleep stages like REM. With the advent of wearable sleep tracking devices, it has become feasible to collect granular, stage-specific sleep data over extended periods in natural sleeping environments. This research investigates the correlation between mattress material density and REM sleep duration using wearablegenerated data. Sixty adult participants (aged 25–55) were monitored over 14 consecutive nights using validated wearables such as the Oura Ring and Fitbit Sense. Participants rotated between mattresses of three density types: low (<30 kg/m³), medium (~50 kg/m³), and high (>70 kg/m³), in a randomized cross-over design. Sleep metrics including REM duration, total sleep time (TST), and sleep efficiency were collected and analyzed using mixed-effects regression models, controlling for variables like age, BMI, and sleep hygiene. The findings indicate that medium-density mattresses are associated with a statistically significant increase in REM sleep duration—averaging 8% higher than low-density mattresses and 12% higher than high-density options (p < 0.01). These results suggest that mattress density exerts a measurable impact on sleep architecture, especially REM sleep. This study offers new insights into personalized sleep optimization and provides actionable guidance for mattress manufacturers and sleep health professionals seeking to enhance sleep quality through material design.