LEVELS – A Whole New Level

Continuous health data gives researchers something they have rarely had before: the ability to follow the same person, in the real world, across thousands of measurements and long periods of time. That can reveal patterns that disappear when we rely on a single clinic visit, a short experiment, or an average drawn across very different people.Mike Haney talks with WHOOP researcher Dr. Greg Grosicki about what scientists are learning from these massive longitudinal datasets, why your own baseline can sometimes matter more than a population reference range, and what continuous measurement could mean as wearables begin capturing far more than heart rate and sleep.Free course: Improve your metabolic healthGet our free email course on how glucose, nutrition, exercise, sleep, and measurement can help you build habits that support better energy and long-term health: ⁠⁠⁠⁠https://levels.link/wnlWhat We Cover:Why HRV is often more useful compared with your own history than with someone else’sWhat millions of nights reveal about alcohol, recovery, and next-day behaviorHow wearable signals can begin changing before you feel sickWhat huge observational datasets can and cannot tell us about cause and effectWhy measuring people continuously may change how we define “normal”🎙️ About the Guest:Dr. Greg Grosicki is a research scientist at WHOOP and an exercise physiologist whose work uses large-scale longitudinal wearable data to study cardiovascular physiology, sleep, activity, recovery, and health behavior.📍What Dr. Greg Grosicki & Mike Haney discussed:00:04 - Compare your HRV with your own history, not someone else's04:20 - Forty people in a lab miss the other 23 hours10:51 - Heart rate, movement, and sleep from one band worn all day13:02 - An 80-year-old can outscore a Tour rider. That is the wrong comparison22:45 - One drink, several drinks, and a last drink before 5 p.m. do not land the same27:28 - Even one drink you do not feel raises heart rate and shortens sleep32:32 - The same drinks hit women harder, and younger adults harder than older ones35:48 - More exercise before drinking made the night worse, not better42:31 - HRV can dip two or three days before you report being sick44:52 - More wear tracks with better numbers. That does not prove the band caused them53:46 - The sharper test is your high-wear weeks against your own low-wear weeks55:32 - HRV can run from about 5 to 400. Stability tells you more than the average1:11:24 - A million nights can hide the one night that is yours1:15:39 - Blood pressure is the measurement he wants on the wrist next🔗 Helpful Links:Real-world effects of alcohol on heart rate, sleep, and physical activity by age and sex — PLOS Digital Health (2026)More than 5 million nights of wearable data on alcohol’s effects. Read the studyHeart rate variability coefficient of variation during sleep as a digital biomarker — American Journal of Physiology (2026)How HRV stability varies with behavior, age, and sex. Read the studyWearing WHOOP More Frequently Is Associated with Better Biometrics and Healthier Sleep and Activity Patterns — Sensors (2025)Longitudinal analysis of nearly one million days and nights. Read the studyAlcohol Use Trajectories During the First 72 Weeks of WHOOP Wearable Platform Membership — JMIR mHealth and uHealth (2026)Alcohol use patterns across 30,000 members over time. Read the studyWatch the conversation: https://youtu.be/Metbt5cMxX4Find us on YouTube: ⁠⁠⁠⁠https://youtube.com/levelshealth?sub_confirmation=1⁠⁠👋 Who we are:Levels helps you understand your metabolic health with personalized data, expert guidance, and tools that connect your daily choices to measurable changes in your body. Our goal is to help you make better decisions about food, exercise, sleep, and long-term health.Look for new shows every month on A Whole New Level, where we have in-depth conversations with thought leaders about metabolic health.

Sleep and diet don’t operate independently. Controlled studies suggest that when people sleep less, they tend to eat more, move less, and gradually gain weight. The relationship also appears to run in the other direction: what and when you eat can influence how well you sleep.Mike Haney talks with Columbia sleep and nutrition researcher Dr. Marie-Pierre St-Onge about what the evidence actually shows at that intersection. Rather than chasing a perfect sleep score or a single “sleep food,” her work points toward a simpler idea: adequate, consistent sleep makes healthy eating easier, and a high-quality diet may help support better sleep in return.Free course: Improve your metabolic healthGet our free email course on how glucose, nutrition, exercise, sleep, and measurement can help you build habits that support better energy and long-term health: ⁠⁠⁠https://levels.link/wnlWhat We Cover:Why even modest chronic sleep loss can accumulate into meaningful sleep debtWhat controlled experiments show about short sleep, calorie intake, and weight gainWhy sleep deprivation tends to shift food choices toward less healthy optionsHow sleep loss affects appetite hormones differently in men and womenWhat the research says about eating close to bedtimeWhether tryptophan, melatonin-rich foods, and specific “sleep foods” actually helpWhy fiber, fruits and vegetables, saturated fat, and refined carbohydrates may influence sleep qualityHow much attention to pay to wearable sleep scores versus how you actually feel🎙️ About the Guest:Dr. Marie-Pierre St-Onge is Professor of Nutritional Medicine at Columbia University Irving Medical Center and Director of its Center of Excellence for Sleep & Circadian Research. Her research focuses on the relationships among sleep, diet, energy balance, body weight, and cardiometabolic health, with extensive work in controlled inpatient and outpatient sleep studies. Vagelos College📍What Dr. Marie-Pierre St-Onge & Mike Haney discussed:05:01 - What popular sleep talk still gets wrong09:30 - A wearable score versus how you actually feel10:37 - Sleep pressure and the body clock13:00 - How a little lost sleep becomes real sleep debt19:43 - Short sleep, and about 300 extra calories27:11 - Six weeks short, and about a pound gained29:05 - Why short sleep shifts you toward worse food30:30 - Appetite hormones don’t respond the same in men and women37:03 - What eating close to bedtime actually does40:20 - Tryptophan, melatonin, and “sleep foods”42:42 - Fruits and vegetables, and less broken sleep46:10 - Saturated fat, refined carbs, and a better cycle🔗 Helpful Links:Marie-Pierre St-Onge — Columbia University: Columbia profileShort sleep duration increases energy intake — American Journal of Clinical Nutrition (2011): PubMedProlonged short sleep and body weight — Annals of Internal Medicine (2026): PubMedSleep extension reduces calorie intake — JAMA Internal Medicine (2022): National Institutes of Health Fruit and vegetable intake and sleep fragmentation — Sleep Health (2025): PubMedFiber, saturated fat, and sleep architecture — Journal of Clinical Sleep Medicine (2016): Vagelos CollegeEat Better, Sleep Better: ihn.cuimc.columbia.eduWatch the conversation: https://youtu.be/WxvbJu_GnSoFind us on YouTube: ⁠⁠⁠https://youtube.com/levelshealth?sub_confirmation=1⁠👋 Who we are:Levels helps you understand your metabolic health with personalized data, expert guidance, and tools that connect your daily choices to measurable changes in your body. Our goal is to help you make better decisions about food, exercise, sleep, and long-term health.Look for new shows every month on A Whole New Level, where we have in-depth conversations with thought leaders about metabolic health.

Medical AI is full of impressive models that work on retrospective datasets. The much harder problem is turning one into a tool that can operate continuously inside a hospital, earn clinicians’ trust, fit into an overloaded workflow, stay reliable across different health systems, and ultimately improve patient outcomes.Mike Haney talks with Johns Hopkins researcher and Bayesian Health founder Dr. Suchi Saria about the decade-long journey from an academic sepsis-prediction algorithm to AI that clinicians are using in hospitals today. Her experience is a reality check on what it actually takes to make medical AI useful, and an argument for aiming higher than documentation and billing: toward systems that continuously watch patients, catch deterioration earlier, and help prevent avoidable harm.Free course: Improve your metabolic healthGet our free email course on how glucose, nutrition, exercise, sleep, and measurement can help you build habits that support better energy and long-term health: ⁠⁠https://levels.link/wnlWhat We Cover:Why sepsis fits continuous AI monitoringHow causal reasoning separates signal from a noisy alertWhy real-time access to the full record mattersWhen a working algorithm still failed to get attentionHow adoption and human-machine teaming became engineering problemsWhat happened when the system went liveHow the same infrastructure extends beyond sepsisWhy healthcare is too conservative about medical AI🎙️ About the Guest:Dr. Suchi Saria is the John C. Malone Associate Professor at Johns Hopkins University, where she directs the Machine Learning and Healthcare Lab, and is the founder and CEO of Bayesian Health. Her work focuses on building and deploying machine-learning systems that use real-world clinical data to improve diagnosis, treatment, and patient safety. 📍What Dr. Suchi Saria & Mike Haney discussed:04:30 - Why the real AI risk is what it is allowed to do08:32 - Why sepsis is a race against organ failure11:57 - From checklists to reading the full medical record16:30 - How causal reasoning finds a patient’s baseline18:50 - Using uncertainty to avoid another noisy alert22:11 - Why an hour-late warning is already too late25:06 - Reading Epic in real time without slowing it down32:35 - A working algorithm still couldn’t get clinicians’ attention35:53 - What happened when the system went live45:32 - Human-machine teaming, and who still makes the call54:17 - The same infrastructure, beyond sepsis58:35 - Why billing and coding is too small a target🔗 Helpful Links:Suchi Saria — Johns Hopkins Research, publications, and academic background.Bayesian Health: Saria’s company commercializing real-time clinical AI.TREWScore — Science Translational Medicine (2015): The original real-time early warning model for septic shock.TREWS patient outcomes — Nature Medicine (2022): Prospective multisite evaluation after deploying the sepsis warning system in clinical care. TREWS clinician adoption — Nature Medicine (2022): Study of provider adoption and effects on sepsis treatment timing.Human-machine teaming — npj Digital Medicine (2022): Clinician interviews on what made the deployed AI system trustworthy and usable.Bayesian Health Sepsis Flagging Device — FDA (2026): FDA 510(k) clearance for the sepsis prediction software discussed in the episode. Watch the conversation: https://youtu.be/uVEKgSvei4sFind us on YouTube: ⁠⁠https://youtube.com/levelshealth?sub_confirmation=1⁠👋 Who we are:Levels helps you understand your metabolic health with personalized data, expert guidance, and tools that connect your daily choices to measurable changes in your body. Our goal is to help you make better decisions about food, exercise, sleep, and long-term health.Look for new shows every month on A Whole New Level, where we have in-depth conversations with thought leaders about metabolic health.

Heart disease is the leading cause of death, but it’s also one of the most preventable. Decades of research have established a strong causal role for LDL and other ApoB-containing particles in atherosclerosis, and we now have multiple proven ways to lower them. The harder question is how to turn that evidence into a decision for an individual person.Mike Haney talks with Johns Hopkins cardiologist Dr. Seth Martin, a co-author of the new 2026 dyslipidemia guidelines, about what the latest evidence says we should actually measure and act on. The throughline is pragmatic: lower exposure to atherogenic particles earlier and for longer, use additional tests when they can change a decision, and distinguish interesting new measurements from ones that have actually been shown to improve outcomes.Free course: Improve your metabolic healthGet our free email course on how glucose, nutrition, exercise, sleep, and measurement can help you build habits that support better energy and long-term health: ⁠https://levels.link/wnlWhat We Cover:Why the evidence that LDL and ApoB-containing particles cause atherosclerosis is so strongWhat “lower for longer” means and how the new LDL and ApoB goals change with cardiovascular riskWhen ApoB adds useful information beyond a standard lipid panelWhy the guidelines recommend against routine LDL particle-size testingHow PREVENT risk scores and coronary calcium scans can help decide when treatment makes senseWhat decades of statin research tell us about benefits, muscle symptoms, and diabetes riskHow much lifestyle changes typically move cholesterol, and when non-statin drugs enter the pictureWhy common heart-health supplements don’t have the evidence behind proven lipid-lowering therapies🎙️ About the Guest:Dr. Seth Martin is a professor of medicine and preventive cardiologist at Johns Hopkins, where he directs the Advanced Lipid Disorders Program and Digital Health and AI Lab at the Ciccarone Center for the Prevention of Cardiovascular Disease. He is a co-developer of the widely used Martin-Hopkins LDL cholesterol equation and served on the writing committee for the 2026 ACC/AHA dyslipidemia guideline.📍What Dr. Seth Martin & Mike Haney discussed:00:04 - LDL and ApoB are causal. Lower for longer07:10 - Guidelines set the standard. Not your doctor11:40 - 2026 shift: earlier treatment, PREVENT, lower goals17:01 - LDL near zero does not eliminate cholesterol19:59 - Hard numbers are back, and lower23:05 - ApoB if a high result changes treatment27:42 - No trial says treat particle size instead of LDL34:51 - PREVENT is for people not already high risk38:52 - Calcium 300 can push the goals. Zero can mean lifestyle first44:29 - The 3% statin line, and the choice just under it51:22 - Muscle symptoms uncommon. Statin can move prediabetes diagnosis earlier56:21 - Lifestyle often lowers LDL about 10%, not the whole benefit59:05 - Other proven drugs when a statin is not enough1:05:31 - Statin beat the supplements. Fish oil can raise AFib risk🔗 Helpful Links:2026 Guideline on the Management of Dyslipidemia: ⁠Read the guideline and supporting materials⁠The New Cholesterol Guideline: What to Know — Johns Hopkins: Read the Johns Hopkins summaryPREVENT-ASCVD Calculator.: ⁠Use the PREVENT calculator⁠Martin-Hopkins LDL Equation: Learn about the Martin-Hopkins methodSPORT Trial — JACC (2022): Read the SPORT trialWatch the conversation: https://youtu.be/vRfhof5dOZwFind us on YouTube: ⁠https://youtube.com/levelshealth?sub_confirmation=1⁠👋 Who we are:Levels helps you understand your metabolic health with personalized data, expert guidance, and tools that connect your daily choices to measurable changes in your body. Our goal is to help you make better decisions about food, exercise, sleep, and long-term health.Look for new shows every month on A Whole New Level, where we have in-depth conversations with thought leaders about metabolic health.

Most of NextLevel starts with a measurement problem: we can see more biology than ever, but we still have to figure out what to do with it. Bioelectronic medicine flips that sequence. We already know how to send electrical signals into the nervous system to change biology, including an FDA-approved vagus nerve treatment for rheumatoid arthritis, even though we still can’t map or read most of the individual nerve fibers carrying those signals.Mike Haney talks with Dr. Kevin Tracey, a pioneer of neuroimmunology and bioelectronic medicine, about what becomes possible when nerves become a therapeutic target. The opportunity is not simply vagus nerve stimulation, but learning which signals control specific organs, then building systems that can read and write them. That is still some distance away, and Tracey separates it from looser claims about vagal tone and vagus nerve hacks.Free course: Improve your metabolic healthGet our free email course on how glucose, nutrition, exercise, sleep, and measurement can help you build habits that support better energy and long-term health: https://levels.link/wnlWhat We Cover:Why the vagus nerve is not one wireHow one minute a day became an FDA-approved rheumatoid arthritis treatmentWhy a nerve target can be more precise than a drugWhy mapping the vagus fiber by fiber is only beginningWhy CRP and cytokines are not a true inflammation readoutWhat HRV, breathing, humming, and cold plunges can and cannot show🎙️ About the Guest:Dr. Kevin Tracey is a neurosurgeon, scientist, and President and CEO of the Feinstein Institutes for Medical Research. His work helped establish how the vagus nerve regulates inflammation and helped launch bioelectronic medicine. He is also co-founder of SetPoint Medical and author of The Great Nerve.📍What Dr. Kevin Tracey & Mike Haney discussed:00:00 - A nerve can treat one organ. A pill cannot04:43 - The vagus nerve is 160,000 fibers, not one wire07:53 - Why the first fiber-by-fiber map of the human vagus is only months old10:29 - FDA-approved vagus nerve stimulation for rheumatoid arthritis14:33 - Why one minute a day can quiet inflammation for 12 to 24 hours17:39 - Why it took 30 years to get from the mouse finding to patients31:53 - How one minute of current reaches millions of immune cells41:19 - Why arthritis has a known mechanism and epilepsy and depression do not49:16 - What single fibers could change in diabetes, the liver, the gut, and stroke recovery52:59 - Why CRP and cytokine levels still fall short of a true readout1:04:18 - Resting heart rate, not HRV, is the cleaner vagus signal1:09:55 - Why deep breathing and humming are not vagus nerve stimulation1:16:35 - A cold plunge is fight-or-flight first, vagus second1:20:23 - The spleen signal he would measure if he could🔗 Helpful Links:The Great Nerve - Kevin J. Tracey (2025)RESET-RA - Nature MedicineSetPoint System - FDAThe inflammatory reflex - Nature (2002)Vagus nerve stimulation in rheumatoid arthritis - PNAS (2016), early human studyVagus nerve stimulation after stroke, paired with rehab - The Lancet (2021)Watch the conversation: https://youtu.be/x_h6Dd_Ap_oFind us on YouTube: https://youtube.com/levelshealth?sub_confirmation=1📲 Connect:Connect with Dr. Kevin Tracey at Feinstein Institutes for Medical Research👋 Who we are:Levels helps you understand your metabolic health with personalized data, expert guidance, and tools that connect your daily choices to measurable changes in your body. Our goal is to help you make better decisions about food, exercise, sleep, and long-term health.Look for new shows every month on A Whole New Level, where we have in-depth conversations with thought leaders about metabolic health.