Bryan Johnson· Author
Track Your Sleep Metrics Metrics to follow: HRV, body temp, respiration rate, REM & deep sleep. I use Whoop and EightSleep. Other sleep trackers are fine too. + Experiment with bedtimes, routines, room temps & find what works + Track data across seasons and when traveling to troubleshoot + Use a sleep journal, tracker, or checklist. You’ll improve what you measure.