In this user's guide to sleep trackers, learn the science behind how they work using motion and optical sensors as Matt explains the key metrics of Sensitivity, Specificity, and Accuracy. Revealing why most trackers overestimate sleep by failing to detect wakefulness, he reveals the crucial difference between a device's flawed "absolute accuracy" and its more valuable "relative accuracy," which highlights the importance of tracking long-term trends over single-night scores.

Matt goes on to examine peer-reviewed data on the Oura Ring, Apple Watch, and Whoop, and introduces the highly accurate, FDA-cleared Happy Ring with its personalized algorithm. Beyond the specs, learn why consistency and form factor are more important than chasing perfect accuracy. The episode also covers the pitfalls of tracking, from the anxiety of "Orthosomnia" to demographic biases in sensor tech, providing a complete guide to choosing and using your device effectively.

Please note that Matt is not a medical doctor, and none of the content in this podcast should be considered medical advice in any way, shape, or form, nor prescriptive in any way.

Podcast partner, AG1, is one that Matt relies upon for his foundational nutrition. Their new science-backed Next Gen formula features upgraded probiotics, vitamins, and minerals. Start your subscription today to get a FREE bottle of Vitamin D3+K2 and 5 free travel packs with your first order at drinkag1.com/mattwalker.

Another sponsor, Shopify, made launching Matt's merchandise incredibly smooth with its integrated sales system. Shopify simplifies everything from online stores to in-person sales. Start your exclusive trial and see for yourself at shopify.com/mattwalker.

In a supplement industry where trust is critical, Matt uses podcast partner Puori. Their protein powders are free from hormones, GMOs, and pesticides, with every single batch third-party tested for over 200 contaminants. For protein you can trust, save 20% at puori.com/mattwalker.

As always, if you have thoughts or feedback you’d like to share, please reach out to Matt:

Matt: Instagram @drmattwalker, X @sleepdiplomat,

YouTube: https://www.youtube.com/channel/UCA3FB1fOtY4Vd8yqLaUvolg

Matt takes a deep dive into REM sleep this week, highlighting methods to enhance this vital stage for emotional regulation and creativity. Detailing pharmacological approaches, he focuses on the neurotransmitter acetylcholine and how medications like donepezil and modern DORAs can boost REM sleep, while also identifying common suppressors like alcohol and THC. Throughout the episode, he also emphasizes that the goal is not to maximize one stage but to achieve a balanced sleep architecture.

The discussion then covers behavioral and lifestyle strategies, explaining how simple changes like sleeping later into the morning, regular exercise, and stress management can remove natural roadblocks to REM. Matt also outlines how managing light exposure - by avoiding blue light at night and getting bright light in the morning - and consuming complex carbohydrates in the evening can further support this dream stage. Finally, the episode touches on emerging technologies like electrical brain stimulation that aim to amplify the brain's natural REM rhythms.

Please note that Matt is not a medical doctor, and none of the content in this podcast should be considered medical advice in any way, shape, or form, nor prescriptive in any way.

One of this week's sponsors, LMNT, offers a science-based electrolyte drink with no sugar or artificial ingredients. Try their new limited-time Lemonade Salt flavor, available May 20th! Get eight free sample packs with any order at drinklmnt.com/mattwalker. Stock up on this summer flavor while it lasts!

Another sponsor, Shopify, made launching Matt's merchandise incredibly smooth with its integrated sales system. Shopify simplifies everything from online stores to in-person sales. Start your exclusive trial and see for yourself at shopify.com/mattwalker.

Our third sponsor this week, David, is a revolutionary new protein bar developed with Dr. Peter Attia. It boasts an unbeatable ratio: 28g of protein and 0g of sugar in just 150 calories. Incredibly satiating with six amazing flavors, it’s perfect for muscle health. Visit davidprotein.com/mattwalker and buy 4 cartons to get a 5th FREE!

As always, if you have thoughts or feedback you’d like to share, please reach out:

Matt: Instagram @drmattwalker, X @sleepdiplomat,

YouTube https://www.youtube.com/@sleepdiplomatmattwalker9299

In this soothing episode, Matt guides you on your personal sleep story towards deep, restorative rest. He invites you to find comfort and release the day's worries through intentional breathing, transporting you to a cozy, imagined haven bathed in soft lights and calming aromas. As twilight descends, experience the tranquil silence and the moon's gentle glow, replacing any turmoil with profound inner peace.

A powerful visualization encourages you to shed thoughts and concerns, picturing them as leaves floating away on a serene river. This practice cultivates gratitude and prepares you to let go completely. Trust that tomorrow brings new joys, and allow yourself to drift effortlessly into sleep, waking up truly refreshed and restored.

Craving more energy, better metabolism, and immunity? Discover Pique's Nandaka, a ceremonial cacao superfood blend for calm, sustained energy without the crash. Thanks to this wonderful podcast partner, you can now get 20% off for life at pique.com/mattwalker using code MattWalker.

As always, if you have thoughts or feedback you’d like to share, please reach out to Matt or Eti:

Matt: Instagram @drmattwalker, X @sleepdiplomat,

YouTube https://www.youtube.com/@sleepdiplomatmattwalker9299