Fit For Science

Stephan Reichl and Rob ter Horst

Two scientists discuss how they live their best life, using science, data, tech, wearables, and systems. Fit For Science is a deep-dive podcast hosted by two biological data scientists, Rob and Stephan, exploring the intersection of research, health tech, and data-driven lifestyle design. The hosts provide evidence-based systems, layered with practical "N=2" personal experimentation, to cut through the noise in the health and fitness industry. The Quantified Scientist (Rob): youtube.com/TheQuantifiedScientist Stephan's Website: http://polytechnist.me

Episodes

  1. Apple Watch Sleep Myths, Why We Quantify & Is Creatine Safe? (Fit For Science Episode 3)

    1 DAY AGO

    Apple Watch Sleep Myths, Why We Quantify & Is Creatine Safe? (Fit For Science Episode 3)

    Rob and Stephan dive into the "deep sleep problem" of the Apple Watch, share their personal motivations for long-term self-quantification, and provide a science-heavy look at why creatine is one of the most underappreciated supplements in medicine. 📝Summary In this episode, Rob addresses the controversy surrounding Apple Watch sleep staging based on a recent study comparing wearables to polysomnography, explaining why the device often underestimates deep sleep stages while remaining a top-tier consumer tool. The hosts explore the "why" behind their data-driven lifestyles, with Rob detailing his unique multi-year deep-phenotyping research and Stephan describing the psychological benefits of leveraging the Hawthorne effect for behavioral change. Finally, they provide a comprehensive breakdown of creatine supplementation, addressing medical misconceptions about kidney health, while also highlighting emerging research on creatine’s cognitive benefits. ⏳Chapters 00:02:00 The Sleep Study: Comparing Apple Watch to the Gold Standard 00:12:41 Staging Accuracy: Pattern Recognition and Consistency Preferences 00:17:15 Battery vs. Precision: Why Apple Limits Sensor Input 00:24:20 Evolving Models: Firstbeat, Garmin, and Machine Learning on the Edge 00:29:48 Why We Track: Rob’s Multi-Year Deep Phenotyping Research 00:38:29 Finding the Niche: From Science Communication to YouTube 00:44:17 Daily Routines: When and How to Check Your Data 00:50:52 Healthy Limits: Preventing Tracking-Induced Anxiety 00:56:48 Creatine and Kidney Health: Addressing Doctor Concerns 00:57:50 Informed Discussions: How to Present Data to Medical Professionals 01:08:18 Cellular Energy: Creatine’s Role in ATP Production 01:13:04 Brain Health: Creatine for Sleep Deprivation and Neuroprotection 01:19:32 Personal Risk Analysis: Hair Loss, Finasteride, and Trade-offs 01:28:03 Soleus Muscle Correction and Smartwatch Histories 📚Resources Rob's sleep study preprint: https://osf.io/preprints/psyarxiv/27wun_v1  Apple sleep staging paper: https://www.apple.com/health/pdf/Estimating_Sleep_Stages_from_Apple_Watch_Oct_2025.pdf  Quantization in AI: https://arxiv.org/abs/2106.08295  Oura technical support confirmed that Oura's sleep staging is processed offline by the Oura App, which runs the complete sleep staging pipeline using the physiological signals shared by the ring, regardless of internet connection. Simon Sinek's Start with Why: https://youtu.be/u4ZoJKF_VuA  EXG Glossary: EEG (Electroencephalogram), EOG (Electrooculogram), ECG  (Electrocardiogram), EMG (Electromyogram) Supplement research database: https://examine.com  Goodhart's Law: When a measure becomes a target, it ceases to be a good measure. Kidney physiology: https://youtu.be/l128tW1H5a8  Stephan's Creatine page: https://stephanreichl.notion.site/Creatine-117301f67e4c80fcbce8e9f489aad9c9  Hypertrophy (size) vs hyperplasia (numbers): https://pubmed.ncbi.nlm.nih.gov/5917072/  Fidgeting (NEAT) study: https://pubmed.ncbi.nlm.nih.gov/11101470/  🎙️About Fit For Science is a deep-dive podcast hosted by two biological data scientists, Rob and Stephan, exploring the intersection of research, health tech, and data-driven lifestyle design. The hosts provide evidence-based systems, layered with practical "N=2" personal experimentation, to cut through the noise in the health and fitness industry. Learn more: https://www.fitforscience.com/  Subscribe on your favorite platforms YouTube: https://www.youtube.com/@FitForScience  Spotify: https://open.spotify.com/show/56TjUxuMsPETb0kGEJ7nwf  Apple Podcasts: https://podcasts.apple.com/us/podcast/fit-for-science/id1863479802 Amazon Music: https://music.amazon.de/podcasts/c3e54ee7-4a2c-442e-a59f-553fbfb02b11/fit-for-science  ⚠️Disclaimer: This podcast represents our own opinions and is for informational purposes only. It does not constitute medical or financial advice or a professional relationship.

    1h 36m
  2. Blue-Light Blockers, What to Track with Wearables & Plogging: Real Science or Fake Marketing? (Episode 2)

    28/12/2025

    Blue-Light Blockers, What to Track with Wearables & Plogging: Real Science or Fake Marketing? (Episode 2)

    Biological data scientists Rob and Stephan discuss what to track and why, the psychological value of blue-light blocking glasses, and the multifaceted longevity benefits of "plogging". 📝Summary In this episode, biological data scientists Rob and Stephan dive deep into the philosophy of self-quantification. They explore why tracking the "unobservable" state of sleep provides the highest return on investment and how the Hawthorne Effect can be used as a personal tool for behavior change. The discussion shifts to the science of blue light blocking glasses, debunking common marketing claims while acknowledging the power of psychological anchors in evening routines. Finally, the hosts introduce "Plogging", the Swedish habit of picking up litter while jogging, as a multifaceted longevity practice that combines movement, grip strength, and community purpose. ⏳Chapters 00:00:53 Wearables Philosophy: A discussion on what to track and why 00:03:44 The SNAP Framework: Sleep, Nutrition, Activity, and Purpose 00:06:18 Differentiating between Activity vs. Exercise 00:09:41 Training Intensity: HIIT for speed and Zone 2 training for endurance 00:15:30 Hardware Deep Dive: Comparing sports tracking versus sleep staging 00:18:34 GPS Math and Measurement Noise: How devices calculate distance 00:22:57 Market Leaders and Reviewer Ecosystems 00:33:25 Blue Light Blocking Glasses: Examining the shifting evidence 00:46:40 Psychological Anchors: How wearing red glasses signal to begin the evening routine 00:49:56 Cold Exposure: Debunking metabolic and fat-loss claims 00:55:38 Advanced Sleep Tech: EEG, polysomnography, and 30-second sleep staging epochs 01:11:22 Tool Time - Plogging: Stephan introduces the ultimate longevity habit 01:19:50 Systematic Culture: Comparing rule-following cultures in Austria vs the Netherlands 01:28:40 Ig Nobel Science: Maternal garlic ingestion 01:32:38 Immune System Triggers: How immune events may trigger Vitiligo 📚Resources Plogging: https://en.wikipedia.org/wiki/Plogging Plogging device: https://www.amazon.de/dp/B09L2M9BPC Plogging instructions: https://stephanreichl.notion.site/2d4301f67e4c804a8be1d693086c2c14  Optimistic Nihilism by Kurzgesagt: https://youtu.be/MBRqu0YOH14  Exercise smart watch companies founding years and countries: Polar 1977 Finland, Garmin 1989 USA (since 2010 Swiss), and Coros 2014 China Stephan's evening routine: http://evening.polytechnist.me  Stephan's morning routine: http://morning.polytechnist.me  💡Corrections Why We Sleep by Matthew Walker (https://www.goodreads.com/book/show/34466963-why-we-sleep) was published in 2017, not 2014. Stephan started sleep tracking in 2016 with an iPhone app called Sleep cycle (https://sleepcycle.com/) and therefore thought the book must have been released before (turns out he was just ahead of his time). 🎙️About Fit For Science is a deep-dive podcast hosted by two biological data scientists, Rob and Stephan, exploring the intersection of research, health tech, and data-driven lifestyle design. The hosts provide evidence-based systems, layered with practical "N=2" personal experimentation, to cut through the noise in the health and fitness industry. Learn more: https://www.fitforscience.com/ Subscribe on your favorite platforms YouTube: https://www.youtube.com/@FitForScience Spotify: https://open.spotify.com/show/56TjUxuMsPETb0kGEJ7nwf Apple Podcasts: https://podcasts.apple.com/us/podcast/fit-for-science/id1863479802 Amazon Music: https://music.amazon.de/podcasts/c3e54ee7-4a2c-442e-a59f-553fbfb02b11/fit-for-science ⚠️Disclaimer: This podcast represents our own opinions and is for informational purposes only. It does not constitute medical or financial advice or a professional relationship.

    1h 35m
  3. Best Smart Rings, Sleep Lab Results & VO2 Max Study: How Two Scientists Really Use Wearables (Episode 1)

    22/12/2025

    Best Smart Rings, Sleep Lab Results & VO2 Max Study: How Two Scientists Really Use Wearables (Episode 1)

    In this inaugural episode, biological data scientists Rob and Stephan dive into the world of self-quantification. They discuss their personal setups, the reliability of popular smart rings, and share exclusive preliminary results from recent independent validation studies on sleep and fitness tracking. 🔬 Summary Two scientists, Rob (chemist turned bioinformatician) and Stephan (mathematician turned bioinformatician), explore the intersection of technology and health. The Smart Ring Showdown: A deep dive into why the Oura Ring remains the current leader in sleep tracking despite battery durability issues and subscription hurdles. Oura technical support clarified (after some back and forth) that Oura's sleep staging is processed locally within the Oura App and is not updated or changed when the phone is connected to the internet. The ring records physiological signals and shares this data with the Oura App, which then runs the complete sleep staging pipeline offline. Sleep Study Insights: Rob shares findings from a 20-person sleep lab study (PsyArXiv preprint) comparing wearables against Polysomnography (PSG). Discover why the Apple Watch struggled with deep sleep while Oura remained remarkably consistent. The CIRCUL ring was, in fact, the worst-performing device. Participants were woken up at 3:00 am, not three hours after going to bed. Fitness Tracking (VO2max): An overview of an ongoing study at the Sports Institute in Vienna, examining how well watches from Garmin, Polar, Apple and Samsung estimate your aerobic capacity Bio-Logic: A look at the "Soleus Pushup" for glucose metabolism, the medical necessity of straight teeth for longevity, and the evolutionary theories behind "rear end" hair triggered by Hank Green's hilarious short. Correction: The Soleus muscle is located on the back of the calf, and is considered part of the calf muscle group, despite not being on the shin. ⏳ Chapters 00:00:00 Introduction: Meet Rob and Stephan 00:01:37 Smart Rings: Form Factor, Convenience, and Battery Woes 00:04:17 Customer Support and Hardware Reliability in Wearables 00:06:22 Rob’s Current Testing Suite: Samsung Galaxy Ring vs. Oura 00:07:58 Stephan’s Routine: How a Scientist Interprets Oura Data 00:10:04 Heart Rate Variability (HRV) and Temperature Baselines 00:12:04 The Case for "N=2": Cross-Validating with Multiple Devices 00:14:50 The Evolution of Heart Rate Tracking: PPG vs. ECG 00:18:04 Comparing the App Experience: Oura, Whoop, and Samsung 00:20:46 Budget Alternatives: The Amazfit Ecosystem 00:22:37 Introducing "Fit4Science": The Philosophy 00:24:40 News: Inside an Independent Sleep Validation Study 00:27:12 Results: Oura vs. Apple Watch vs. Garmin in Sleep Staging 00:30:51 Biases in Sleep Algorithms: Expectation vs. Reality 00:34:33 Longevity Corner: Why Stephan Got Braces at 34 00:46:59 VO2 Max Study: Testing the Accuracy of Fitness Estimates 00:54:08 Human Efficiency: Energy Expenditure 00:59:50 Height, Confidence, and Biological Advantages 01:03:14 Body Types: Ectomorphs, Mesomorphs, and Endomorphs 01:09:14 Genetic Testing and Hair Loss Prevention 01:11:06 The "Elephant" in the Room: Why Rob Has 8 Bicycles 01:17:14 Risk Assessment: Cycling Safety in Vienna vs. The Netherlands 01:27:10 Funny Science: Why Do Humans Have Body Hair (at the “Rear End”)? 01:31:34 Smells, Pheromones, and Evolutionary "Leftovers" 01:34:59 Closing Thoughts and How to Support the Show About Fit for Science is a deep-dive podcast hosted by two biological data scientists, Rob and Stephan, exploring the intersection of research, health tech, and data-driven lifestyle design. We cut through the noise to provide evidence-based systems, layered with practical "N=2" personal experimentation. Learn more: fitforscience.com YouTube: @FitForScience Disclaimer: This podcast represents our own opinions and is for informational purposes only. It does not constitute medical or financial advice or a professional relationship.

    1h 35m
  • 3 Episodes

About

Two scientists discuss how they live their best life, using science, data, tech, wearables, and systems. Fit For Science is a deep-dive podcast hosted by two biological data scientists, Rob and Stephan, exploring the intersection of research, health tech, and data-driven lifestyle design. The hosts provide evidence-based systems, layered with practical "N=2" personal experimentation, to cut through the noise in the health and fitness industry. The Quantified Scientist (Rob): youtube.com/TheQuantifiedScientist Stephan's Website: http://polytechnist.me

Information

  • Creator
    Stephan Reichl and Rob ter Horst
  • Years Active
    2025 - 2026
  • Episodes
    3
  • Rating
    Clean
  • Copyright
    © Stephan Reichl and Rob ter Horst
  • Show Website
    Fit For Science