Neurotransmitter Release, Lactate, and the Runner’s High

In this episode, Angela sits down with Ulrich Dempfle, co-founder and CEO of CAROL Bike, to uncover the science and innovation behind one of the most time-efficient ways to boost VO₂ max, metabolic health, and brain function.

Ulrich explains why VO₂ max is the most important marker for longevity, how it declines without training, and how short, AI-guided REHIT sprints boost mitochondria, BDNF (brain-derived neurotrophic factor), and cardiovascular fitness in just minutes.

He also breaks down how Reduced-Exertion High-Intensity Interval Training (REHIT) works, why traditional zone 2 training doesn’t work for everyone, and how gamification and real-time performance data make staying consistent easier than ever.

What You’ll Learn:

• Why VO₂ max is the strongest predictor of health and longevity

• How REHIT delivers major fitness gains in just minutes

• Why zone 2 training doesn’t work for everyone

• How short, AI-guided sprints boost mitochondria and brain function

• Metabolic and cognitive benefits of REHIT

• How CAROL Bike personalises training to maximise VO₂ max

TIMESTAMPS

00:00 Intro & The Importance of VO₂ Max

01:00 How VO₂ Max Declines and Why It Matters

04:22 Zone 2 Training Myths & Non-Responders

09:09 Mitochondria 101: Density vs. Efficiency

12:00 The Science Behind REHIT & CAROL Bike

19:09 Gamification, Dopamine & Workout Adherence

22:02 Lactate, BDNF & Brain Health Benefits

26:04 Insulin Sensitivity & Metabolic Effects

30:17 Efficient Weekly Training Structure

34:51 Afterburn Effect & Fat Oxidation Misconceptions

45:00 VO₂ Max Testing & Fitness Score Tracking

52:00 Peer-Reviewed Research & AI Personalisation

57:30 Real-World VO₂ Max Improvements

1:01:00 How to Get Started & Special Listener Offer

VALUABLE RESOURCES

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A BIG thank you to our sponsors who make the show possible:

• Exclusive discount for podcast listeners on Carol Bike - the bike that gets you fittest the fastest - click here WWW.CAROLBIKE.COM and use code ANGELA

• Hormone Harmony - go to LVLUPHEALTH.COM/ANGELA and use the code ANGELA at checkout for an exclusive 15% off

ABOUT THE GUEST

Ulrich Dempfle is the CEO and co-founder of CAROL Bike, the world’s first Reduced Exertion HIIT (REHIT) exercise bike. Originally trained as a mechanical engineer in Germany, Ulrich began his career in the automotive industry before moving to the UK to pioneer AI in healthcare systems.

After discovering REHIT through a BBC documentary, he partnered with leading exercise scientists to bring this lab-based protocol to the public. Today, Ulrich leads CAROL’s product development, combining science, data, and technology to deliver the most time-efficient cardio workout.

• CAROL website: https://carolbike.com/

• Find CAROL Bike on all platforms @theCAROLbike

ABOUT THE HOST

Angela Foster is an award-winning Nutritionist, Health & Performance Coach, Speaker, and Host of the High Performance Health podcast. A former Corporate lawyer turned industry leader in biohacking and health optimisation for women, Angela has been featured in Huff Post, Runners World, The Health Optimisation Summit, BrainTap, The Women’s Biohacking Conference, Livestrong & Natural Health Magazine.

Angela is the creator of BioSyncing®️, a blueprint for ambitious entrepreneurial women to biohack their health so they can 10X how they show up in their business and family without burning out.

DISCLAIMER

The High Performance Health Podcast is for general information purposes only and does not constitute professional or coaching advice, nor does it form a client relationship. The use of information on this podcast, or materials linked from this podcast, is at the user's own risk. Always seek advice from your medical doctor or healthcare professional before implementing any changes.