The Insights Journal
Articles and coaching philosophy from Dr. Jason Rannfeldt on health, human performance, nutrition, men's health, and identity transformation.
More Articles
Dr. Jason Rannfeldt on Caffeine and Executive Performance: The Right Way to Use the World's Most Common Performance Drug
Caffeine is the most widely used performance drug on the planet and the most poorly timed. Dr. Jason Rannfeldt breaks down how caffeine actually works on adenosine, cortisol, sleep architecture, HRV, and glucose regulation — and the eight-week protocol that turns caffeine from a stimulant crutch into a precision tool for executive focus, energy, and long-horizon performance.
Read MoreDr. Jason Rannfeldt on Alcohol and Executive Performance: The Hidden Cost of the Two-Drink Habit
Two drinks a night is not neutral. Dr. Jason Rannfeldt breaks down what alcohol does to sleep architecture, HRV, testosterone, glucose regulation, and next-day cognition — and the eight-week reset protocol that restores executive energy, focus, and body composition without demanding permanent abstinence.
Read MoreDr. Jason Rannfeldt on Stress Resilience and Nervous System Regulation for Executives
Dr. Jason Rannfeldt explains why executive burnout is a nervous system problem, not a mindset problem — and the physiological protocol that rebuilds true stress resilience in eight weeks.
Read MoreDr. Jason Rannfeldt on Deep Work and Cognitive Endurance for Executives: The Physiology of Sustained Focus in a Distraction Economy
Deep work is not a productivity trick — it is a physiological state that depends on sleep, glucose, dopamine regulation, and nervous-system tone. Dr. Jason Rannfeldt breaks down the biology of sustained focus, why most executives lose it by 2 p.m., and the eight-week protocol that rebuilds four hours of daily deep work without stimulants, hustle, or burnout.
Read MoreDr. Jason Rannfeldt on Fasting and Metabolic Reset for Executives: The Protocol That Restores Insulin Sensitivity, Focus, and Body Composition
Intermittent fasting is oversold to the wrong people and underused by the right ones. Dr. Jason Rannfeldt breaks down the physiology of fasting, who actually benefits, the mistakes that erase the upside, and the eight-week executive protocol that restores insulin sensitivity, mental clarity, and body composition without wrecking sleep, training, or hormones.
Read MoreDr. Jason Rannfeldt on Testosterone Optimization for Men Over 40: The Lifestyle Blueprint Before the Prescription
Testosterone is the hormone most misunderstood in men's health. Dr. Jason Rannfeldt breaks down what actually drives natural testosterone in men over 40 — sleep, training, nutrition, stress, and body composition — and the eight-week lifestyle protocol that reliably restores it before any prescription enters the conversation.
Read MoreDr. Jason Rannfeldt on Blood Sugar and Executive Focus: The Metabolic Foundation of Cognitive Performance
Blood sugar stability is the hidden variable behind executive focus, decision quality, and afternoon energy. Dr. Jason Rannfeldt breaks down the physiology, the CGM data, and the eight-week protocol that rebuilds glucose control in high performers.
Read MoreDr. Jason Rannfeldt on VO2 Max: The Longevity Metric Every Executive Should Train
VO2 max is the single strongest predictor of all-cause mortality and long-term performance. Dr. Jason Rannfeldt breaks down the physiology, the 12-week protocol, the testing methods, and why VO2 max is the most under-trained executive metric.
Read MoreDr. Jason Rannfeldt on Sleep Optimization for Executives: The Performance Lever No One Trains
Sleep is the single highest-leverage performance intervention available to executives. Dr. Jason Rannfeldt breaks down the physiology, protocol, and 90-day rebuild that restores deep sleep, REM, hormones, and cognition.
Read MoreDr. Jason Rannfeldt on Mitochondrial Health: The Cellular Engine of Executive Energy
Energy, focus, recovery, and longevity all trace back to one place — the mitochondria. Dr. Jason Rannfeldt breaks down the science of mitochondrial health and the exact protocol he uses to rebuild cellular energy in high performers.
Read MoreDr. Jason Rannfeldt on Leadership, Health, and the Physiology of Executive Performance
Dr. Jason Rannfeldt on why great leadership is a physiological output — how sleep, hormones, nervous system regulation, and identity shape the decisions executives make.
Read MoreDr. Jason Rannfeldt on Protein and Muscle for Longevity
Dr. Jason Rannfeldt on why protein intake and muscle mass are the single most important predictors of healthspan — with the exact protocol he uses with executives and high performers over 40.
Read MoreDr. Jason Rannfeldt on Cold Exposure and Recovery
Dr. Jason Rannfeldt breaks down the science of cold exposure — how deliberate cold plunges, cold showers, and contrast therapy improve recovery, dopamine, inflammation, and resilience for high performers.
Read MoreDr. Jason Rannfeldt on Morning Light and Circadian Performance: The 10-Minute Habit That Rebuilds Energy, Sleep, and Focus
Dr. Jason Rannfeldt explains why morning sunlight is the most under-used performance and longevity lever for high achievers — the science of the circadian system, the exact protocol he uses with executive clients, and how it upgrades sleep, mood, hormones, and cognition.
Read MoreDr. Jason Rannfeldt on Hydration and Electrolytes: The Simplest Performance Lever Almost Everyone Gets Wrong
Dr. Jason Rannfeldt breaks down the real science of hydration and electrolytes — why plain water is not enough, how dehydration silently kills executive performance, and the daily protocol he uses with high-performing clients.
Read MoreDr. Jason Rannfeldt on Strength Training After 40: The Non-Negotiable Longevity Skill
Dr. Jason Rannfeldt explains why strength training is the single most important physical practice after 40 — and the exact framework he uses to build muscle, protect joints, and extend healthspan for busy high performers.
Read MoreDr. Jason Rannfeldt on Gut Health: The Overlooked Foundation of Energy, Focus, and Immunity
Dr. Jason Rannfeldt explains why gut health drives energy, mood, immunity, and metabolic performance — and the practical protocol he uses with high-performing clients.
Read MoreDr. Jason Rannfeldt on Zone 2 Training: The Aerobic Base Every Executive Is Missing
Zone 2 is the highest-leverage, lowest-cost aerobic intervention for executive performance. Dr. Jason Rannfeldt explains the physiology, the protocol, and the 90-day rebuild that restores mitochondrial capacity, HRV, and metabolic flexibility.
Read MoreDr. Jason Rannfeldt on Zone 2 Training: The Longevity Cardio Method High Performers Ignore
Dr. Jason Rannfeldt breaks down Zone 2 training — the low-intensity cardio protocol that builds mitochondria, stabilizes energy, and extends healthspan for executives and high performers.
Read MoreDr. Jason Rannfeldt on Resilience and Identity: The Inner Architecture of High Performers
Dr. Jason Rannfeldt on why resilience is built before it is needed — and how identity work is the missing layer in most executive health and performance programs.
Read MoreDr. Jason Rannfeldt on HRV: The Recovery Metric That Predicts Everything
Dr. Jason Rannfeldt explains how heart rate variability reveals nervous system load, recovery capacity, and the hidden cost of high-performance living.
Read MoreDr. Jason Rannfeldt on Metabolic Health: The Foundation High Performers Ignore
Dr. Jason Rannfeldt explains why metabolic health is the single most overlooked driver of energy, longevity, and performance — and the protocol he uses with clients.
Read MoreMental Clarity and Brain Health for Executives: The Dr. Jason Rannfeldt Framework
Dr. Jason Rannfeldt explains the upstream drivers of brain fog, focus loss, and cognitive decline — and the protocol that restores clarity for high performers.
Read MoreLongevity Strategies for High Performers: What Dr. Jason Rannfeldt Recommends
Dr. Jason Rannfeldt breaks down the longevity strategies that actually move the needle for executives and high performers — beyond the supplement hype.
Read MoreWhy Cortisol Is the Hormone Nobody Talks About (And How It Quietly Wrecks High Performers)
Dr. Jason Rannfeldt explains how chronically elevated cortisol drives fatigue, belly fat, poor sleep, and burnout in high performers — and the protocol to bring it back into balance.
Read MoreThe Real Cost of Poor Sleep for High Performers (And How to Fix It)
Dr. Jason Rannfeldt breaks down how poor sleep silently destroys executive performance, hormones, and longevity — and the exact protocol he uses to rebuild it.
Read MoreAutoimmune Recovery: What Works When Medicine Runs Out of Answers
Dr. Jason Rannfeldt shares the protocol that helped him reverse his own autoimmune condition — and what he now teaches clients facing similar diagnoses.
Read MoreThe Hidden Cost of Being a High Performer (And the System to Fix It)
Jason Rannfeldt on why success often comes at the expense of health — and the five non-negotiables that restore energy without sacrificing output.
Read MoreThe Truth About Testosterone and Male Vitality After 35
Dr. Jason Rannfeldt cuts through the noise on testosterone, hormone health, and the real drivers of male vitality, energy, and longevity after 35.
Read MoreWhy Most Health Programs Fail High Achievers
Dr. Jason Rannfeldt explains why generic wellness programs collapse under the demands of executive life — and what actually works for high performers.
Read MoreRebuilding Health After Burnout: A Systems Approach
Dr. Jason Rannfeldt outlines a five-pillar system for rebuilding energy, hormones, and identity after burnout — without quick fixes.
Read MoreInflammation and Modern Performance: What Most People Miss
Chronic inflammation is the silent ceiling on energy, focus, and recovery. Jason Rannfeldt breaks down the common drivers and how to address them.
Read MoreMen's Health and the Identity Rebuild Most Coaches Skip
Physical change without identity change does not last. Dr. Jason Rannfeldt on why men's health programs fail — and what makes Crush 90 different.
Read MoreExecutive Performance Without the Grind
High performance and self-destruction are not the same thing. Jason Rannfeldt on coaching executives to perform at the top without burning the body down.
Read MoreNutrition Fundamentals That Actually Work
Forget the fads. Jason Rannfeldt's nutrition principles are simple, sustainable, and backed by 25+ years of coaching results.
Read More