Billat 30-30 Physiology: Using SmO2 and ThB to Identify True VO2max Stimulus

Comparison of SmO2 resaturation capacity in early vs. late Billat intervals showing the failure of muscle re-oxygenation.

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 Half-Glass Difference: How Alcohol Sabotages Your Garmin Recovery

A glass of red wine on a dinner table at an upscale restaurant, representing the setting for a physiological case study on recovery.

When analyzing Garmin sleep recovery, alcohol is often the “X-factor” that derails even the most disciplined athlete. We’ve all heard it before: “It was just a couple of glasses of wine.” But as a coach who lives by the mantra Physiology is King, I’m less interested in what the menu says and more interested in […]

98% Charged: The +61 Garmin Body Battery Bounce Back

Garmin Body Battery 28-day chart showing a peak of 98.

The Great Recharge: How I Pushed My Garmin Body Battery Back to 98 By Richard Wharton Achieving a massive Garmin Body Battery recharge is the ultimate goal after the physical toll of outdoor labor drains you to zero. Following up on my last post, I wanted to share the physiological “bounce back” results that took […]

Garmin Guru Deep Dive: Decoding the Internal Response to 4-Minute VO2max Intervals

A consolidated physiological data graph of a 5x4 minute VO2max cycling session, showing overlapping data for VO2 consumption, Moxy SmO2 (muscle oxygenation), heart rate, and power output.

Garmin Guru Deep Dive: Decoding the Internal Response to 4-Minute VO2max Intervals Today’s session of 4-minute VO2max intervals was a masterclass in why I lead with physiology, not physics. As the Garmin Guru at Online Bike Coach, I’m constantly looking for the “truth” behind the numbers. Today, that truth was found in gas exchange and […]

Garmin HRV Stress Balance: When Life Gets in the Way

Garmin HRV Status graph showing 4‑week HRV trends with balanced and unbalanced readings, baseline range, and overnight HRV summary.

Garmin HRV Stress Balance: When Life Gets in the Way My training, recovery, and daily decisions start with Garmin HRV Stress Balance. I love the fantasy version of training: ride hard, lift heavy, eat clean, sleep eight hours, repeat. And with all the data my Garmin wearables give me — especially my older Garmin Fenix […]

The Garmin Ecosystem: Why Your Watch is More Important Than Your Power Meter

Updated Garmin Recovery Time of 13 hours showing Train as Usual status after a night of rest.

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 […]

Physiology First: Navigating a “Red Light” Morning with AlphaHRV

Screenshot of a Garmin HRV Stress test showing a high stress score of 75.

    Physiology First: My Red Light Recovery Ride This morning was a masterclass in why I apply a Physiology First framework to every session, looking at the internal engine before I look at the wattage. Between a late meal and the devastating news about my friend Murray being struck by a motorist—suffering a serious […]

Physiological Threshold Vs. FTP: The Power Illusion

Graph of SmO2, VO2, and power data showing physiological threshold during 4x8 intervals.

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 […]

Altitude, Heat, and the Power Curve: Practical Physiology for Endurance Athletes

Two people in conversation at an outdoor table with rolling hills and cloudy sky behind them

Elite performance is built on a careful balance between stress and recovery, biology and behavior. This article translates practical lessons from applied sports science into usable guidance for endurance athletes and coaches. It covers how simulated altitude works, why erythropoiesis is not as simple as “more red blood cells = better,” how heat affects different […]