Cracking the Code: My Physiology First Tabata VO2 Max Deep Dive
Cracking the Code: My Physiology and the Tabata Triple Threat Preface: The Metabolic Green Light vs. The CNS Red Light Before I even turned a pedal, the data was already telling a nuanced story. I woke up with a solid 83 sleep score and a body battery that recharged to 85—clear signals that my recovery […]
Stamina, Speed, Strength, and Skill – 4 Spokes With a Hub called “Consistency”.
Cycling Stamina and Strength: The S4 Framework Building elite cycling stamina and strength is the foundation of the S4 performance framework used by high-performance athletes.In the world of professional cycling, we often get distracted by the latest gear or chasing the highest wattage. But at its core, your performance is a wheel supported by four […]
Why Your “Free” Garmin Metrics are More Accurate Than You Realize
Why Your “Free” Garmin Metrics are More Accurate Than You Realize When athletes ask about Garmin VO2 Max accuracy, they are usually skeptical about whether a consumer wearable can truly measure the high-octane reality of a 15-15 interval set. On paper, today’s session was a classic builder—two sets of 15-minute micro-intervals—but as a physiology-first coach, […]
Billat 30-30 Physiology: Using SmO2 and ThB to Identify True VO2max Stimulus
Billat 30-30 Physiology: Why Garmin Stamina Contradicts the SmO2 Test By Coach Wharton April 29, 2026 Billat 30-30 Physiology is a foundational concept in high-intensity training, typically involving 30 seconds of maximal aerobic power followed by 30 seconds of active recovery. The goal is simple on paper—spend as much time as possible at VO2max intensity. […]
The Garmin Ecosystem: Why Your Watch is More Important Than Your Power Meter
Garmin Recovery Time: Why Your Watch Beats Your Power Meter By The Garmin Guru | April 24, 2026 Understanding Garmin Recovery Time is essential for any athlete following a “Physiology First” approach. As a coach with over 20 years in the industry, I know that your bike computer is only half the story. To truly […]
Physiological Threshold Vs. FTP: The Power Illusion
The Power Illusion: Resetting 20 Years of Training with Physiological Data After 20 years of cycling, I realized my FTP wasn’t telling the whole story of my actual physiological threshold. My identity as a cyclist was defined by a single, flickering number on a head unit: Watts. If you’ve spent any significant time in the […]
75 XSS For 75 Days – Six Weeks In
75 XSS As a Minimum Volume for a Ride Is Showing Some Results Achieving 75 XSS (Xert Strain Score) points for every ride is leading to some interesting results. While I thought I was being consistent, it’s been a challenge. Most weeks have gone in a “4 rides”, one day off, 3 rides, one day […]
75 XSS for 75 Days – 3 Weeks In.
75 XSS Is Bringing me VOLUME, But What Else Am I Accomplishing? ***** THIS DID NOT PUBLISH ON JULY 4th, 2021 LIKE I EXPECTED. PLEASE EXCUSE THE TECHNICAL GLITCH. I AM WORKING ON AN END-OF-JULY REPORT NOW. ******* XSS (Xert Strain Score) is a metric that looks at the time you spend riding, the energy […]
75 XSS for 75 Days – First 14 Days
75 XSS for 75 Days – What’s Happening to my Fitness? XSS Stands for Xert Strain Score. It’s a way to combine time and energy at different intensities. It’s a measure of Cycling Volume. While I unofficially began thinking about this goal in late May, I announced the plan on this forum later, in Mid […]
Using Xert to Show an MD Why You Think There’s Something WRONG With Your Heart.
Xert Metrics Can Show You When Things May Be Wrong Beyond Means Which You Can Control. Today’s Xert Daily Ditty is really an interview where one of my long-time clients, who is also a teammate and friend, explains how he knew something was wrong when he saw his Xert XPMC metrics dropping. He tried everything. […]