Over a 28-day period, 20 adults ranging in age from 24 to 75 tracked their sleep using the WHOOP Health & Sleep Tracker—a leading tool used by athletes, professionals, and sleep scientists alike. Participants spent between 14 to 21 nights sleeping on the Twilla Orthopedic Pillow, and 7 to 14 nights using a different (non-Twilla) pillow.

The focus? Measuring the difference in Sleep Scores and Recovery Scores—two key indicators of sleep quality and physiological recovery.

Sleep Scores: 

The WHOOP Sleep Performance Score measures overall sleep quality based on:

• Sleep Sufficiency (hours slept vs. hours needed)

• Sleep Consistency

• Sleep Efficiency

• Sleep Stress

Twilla users averaged an 89% sleep score, compared to just 78% with other pillows—a 12% improvement in overall sleep performance.

Recovery Scores: 

WHOOP’s Recovery Score reflects how well your body has recovered overnight—factoring in heart rate variability (HRV), resting heart rate (RHR), and sleep quality.

Twilla users averaged a 76% recovery score, while the average recovery score on other pillows was only 63%—that’s a 17% improvement in nightly recovery.

Why We Trust the Data

Unlike generic surveys or subjective feedback, this study used objective, biometric data from WHOOP, a trusted health performance tracker. That means the results weren’t based on how users felt—they were based on measurable physiological improvement.