What is ReHIT and four-second sprints

Your workouts may be doing less than you think, and science now proves why. This episode reveals how to build muscle, improve metabolism, and extend longevity in a fraction of the time using blood flow restriction training and intermittent hypoxia. You’ll learn how to hack your mitochondria for faster recovery, stronger hormonal balance, and better brain performance without the burnout of high-intensity training. 

Watch this episode on YouTube for the full video experience: 

https://www.youtube.com/@DaveAspreyBPR 

Host Dave Asprey talks with Dr. Sten Stray-Gundersen, PhD, CSCS, one of the world’s leading experts on blood flow restriction (BFR) training and metabolic physiology. With over a decade of research and teaching experience, Dr. Stray-Gundersen has explored how BFR and intermittent hypoxia can improve cardiovascular health, metabolism, and recovery. After earning his doctorate in Exercise Physiology from the University of Texas at Austin, he now serves as an Assistant Professor at the University of South Carolina, where he studies vascular adaptations, cognitive performance, and ergogenic aids. He’s also a B Strong master trainer, developing individualized BFR protocols for athletes, military professionals, and everyday people looking to optimize human performance. 

Together, Dave and Sten uncover how BFR and oxygen cycling unlock powerful adaptations in the body’s vascular, metabolic, and hormonal systems. You’ll learn how strategic stress signals can trigger nitric oxide production, enhance glucose uptake, improve insulin sensitivity, and supercharge mitochondria for better energy and anti-aging benefits. They also explore how these methods can naturally boost testosterone, growth hormone, and even libido, all while protecting the nervous system and improving recovery.  

This episode dives deep into biohacking, functional medicine, and smart exercise efficiency, from Zone 2 and REHIT training to nitric oxide signaling, fasting, nootropics, and precision supplementation. Whether your goal is longevity, strength, or sharper cognition, this conversation shows you how to get maximum results with minimal time using the principles of Smarter Not Harder.  

You’ll Learn:

• How intermittent hypoxia works at the level of partial pressure and why altitude acclimation upgrades mitochondria and performance

• Why hypoxia and muscle contraction increase glucose uptake independent of insulin and improve insulin sensitivity

• How blood flow restriction (BFR) accelerates fatigue with light loads to drive hypertrophy, strength, and vascular adaptations

• How BFR and hypoxia influence testosterone, growth hormone, nitric oxide, and libido through short, targeted stress

• The roles of ENOS, INOS, and NNOS in nitric oxide signaling and what that means for circulation and brain perfusion

• Who benefits most from BFR, including athletes, rehab patients, and older adults who cannot lift heavy

• Why BFR produces systemic and “proximal” gains, including carryover to glutes and upper body during lower limb training

• How to stack BFR with Zone 2, REHIT, and vibration plates for VO2 max, muscle, and time efficiency

Dave Asprey is a four-time New York Times bestselling author, founder of Bulletproof Coffee, and the father of biohacking. With over 1,000 interviews and 1 million monthly listeners, The Human Upgrade brings you the knowledge to take control of your biology, extend your longevity, and optimize every system in your body and mind. Each episode delivers cutting-edge insights in health, performance, neuroscience, supplements, nutrition, biohacking, emotional intelligence, and conscious living. 

New episodes are released every Tuesday, Thursday, Friday, and Sunday (BONUS). Dave asks the questions no one else will and gives you real tools to become stronger, smarter, and more resilient. 

Keywords: Sten Stray-Gundersen, blood flow restriction training, B Strong, intermittent hypoxia, mitochondrial function, nitric oxide production, VO2 max, metabolic efficiency, vascular health, testosterone boost, growth hormone release, anti-aging performance, exercise recovery, glucose metabolism, functional medicine, biohacking fitness, REHIT training, Zone 2 optimization, strength and longevity, human performance science 

Thank you to our sponsors! 

-KILLSwitch | If you’re ready for the best sleep of your life, order now at https://www.switchsupplements.com/ and use code DAVE for 20% off. 

-EMR-Tek | https://www.emr-tek.com/DAVE and use code DAVE for 40% off. 

-Leela Quantum Tech | Check out all HEAL360 products and research and get 10% off at https://leelaq.com/DAVE. 

-ARMRA | Go to https://tryarmra.com/ and use the code DAVE to get 15% off your first order. 

Resources:  

• Use code DAVE10 to get a discount on a BFR band today: https://shopify.bstrong.training/products/b-strong-training-system?ref=dave%2F 

• Dive deeper in Sten’s work at: https://bstrong.training/  

• Danger Coffee: https://dangercoffee.com/discount/dave15  

• My Daily Supplements: SuppGrade Labs (15% Off)  

• Favorite Blue Light Blocking Glasses: TrueDark (15% Off)  

• Dave Asprey’s BEYOND Conference: https://beyondconference.com  

• Dave Asprey’s New Book – Heavily Meditated: https://daveasprey.com/heavily-meditated 

• Upgrade Collective: https://www.ourupgradecollective.com  

• Upgrade Labs: https://upgradelabs.com  

• 40 Years of Zen: https://40yearsofzen.com 

Timestamps: 

0:00 - Trailer 

1:25 - Guest Intro 

5:40 - Intermittent Hypoxia & Altitude Acclimation 

12:11 - Introduction to Blood Flow Restriction (BFR) 

22:53 - Systemic Benefits & Who Can Use BFR 

30:23 - BFR Effects on Hormones & Libido 

40:37 - Nitric Oxide & Vascular Health 

48:15 - Zone 2 Training with BFR 

54:00 - Advanced Protocols: Stacking BFR 

59:15 - Cognitive Enhancement & Wrap-Up 

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