Bryan Johnson tracked eight months of perfect sleep and found resting heart rate was his strongest predictor of sleep quality. Lowering his beats per minute let him fall asleep in one to three minutes, with over two hours of REM and deep sleep each night.
I know from achieving the best sleep score in human history, eight months of perfect sleep, that the single strongest predictor of my nighttime sleep quality is my resting heart rate. Everything I do is to lower the beats per minute of my heart. The lower I go, the better my sleep. At 8:30, my head will hit the pillow and I will be asleep within one to three minutes. On any given night, I will average over two hours of rem, two hours of deep, and I will be up less than 30 minutes a night. These are the markers of exceptional sleep.
