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Physiological Profiling for Hyrox: The ENDUROX Metabolic Calculator Field Test
Physiological Profiling for Hyrox: The ENDUROX Metabolic Calculator Field Test
Estimate VO₂max, VLamax, lactate thresholds and substrate profile using simple field tests — then optimise your HYROX training zones.
Estimate VO₂max, VLamax, lactate thresholds and substrate profile using simple field tests — then optimise your HYROX training zones.
by
Dr. Dan Plews and Dr. Adam Storey
7
min read
At ENDUROX, we put science at the core of training. HYROX demands a unique balance between aerobic endurance and anaerobic power. Understanding where you sit on that spectrum is key to refining your preparation — and that's where physiology comes in.
Traditionally, this required expensive laboratory testing. But with the ENDUROX Metabolic Calculator, you can estimate the same key parameters — thresholds, training zones, substrate utilisation, and metabolic profile — using simple field tests and data from your wearable.
WHY THIS MATTERS FOR HYROX
Mader & Heck's classic model (1986) explained the anaerobic threshold as the point where the balance between lactate formation (from glycolysis) and lactate elimination (via oxidation) tips, causing net accumulation.
VLamax: maximum lactate formation rate (glycolytic power).
VO₂max: maximum oxidative capacity (aerobic engine).
The balance of these two determines your thresholds:
High VLamax: more explosive capacity for sleds and wall balls, but lower thresholds and faster carbohydrate reliance.
Low VLamax: greater endurance and substrate efficiency, but reduced peak power for strength/power based exercise stations.
In HYROX, this trade-off is critical: you need enough glycolytic capacity to handle the stations, but not so much that your running economy collapses.
The calculator uses your VO₂max and VLamax to predict lactate thresholds (LTP1 and LTP2) to set ENDUROX training zones, and a substrate utilisation profile showing how your body shifts between fat and carbohydrate use at different intensities.
HOW TO ESTIMATE VLAMAX
Running Protocol (HYROX-specific): 1) Resting lactate. 2) Warm-up. 3) 15-second all-out sprint. 4) Lactate samples post-sprint. 5) Cool down.
Cycling Protocol: Similar protocol, performed on a stationary bike.
Enter values into the calculator. VLamax guide: Low (0.2–0.4) for endurance; High (≥0.6) for power.
WHAT IS THE IDEAL VLAMAX FOR HYROX?
Aim low enough for endurance (>0.3, <0.6) to sustain running speeds while retaining power for stations.
HOW TO ESTIMATE VO₂MAX
Use a wearable estimate or derive maximal aerobic velocity (MAV) from it.
HOW THE CALCULATOR WORKS
The tool predicts thresholds (LTP1 and LTP2) and substrate shifts using your VO₂max and VLamax inputs.
PUTTING IT INTO PRACTICE
The calculator reveals your training zones, glycolytic power, and physiology type for HYROX optimisation — helping you tailor sessions to your specific metabolic profile.
At ENDUROX, we put science at the core of training. HYROX demands a unique balance between aerobic endurance and anaerobic power. Understanding where you sit on that spectrum is key to refining your preparation — and that's where physiology comes in.
Traditionally, this required expensive laboratory testing. But with the ENDUROX Metabolic Calculator, you can estimate the same key parameters — thresholds, training zones, substrate utilisation, and metabolic profile — using simple field tests and data from your wearable.
WHY THIS MATTERS FOR HYROX
Mader & Heck's classic model (1986) explained the anaerobic threshold as the point where the balance between lactate formation (from glycolysis) and lactate elimination (via oxidation) tips, causing net accumulation.
VLamax: maximum lactate formation rate (glycolytic power).
VO₂max: maximum oxidative capacity (aerobic engine).
The balance of these two determines your thresholds:
High VLamax: more explosive capacity for sleds and wall balls, but lower thresholds and faster carbohydrate reliance.
Low VLamax: greater endurance and substrate efficiency, but reduced peak power for strength/power based exercise stations.
In HYROX, this trade-off is critical: you need enough glycolytic capacity to handle the stations, but not so much that your running economy collapses.
The calculator uses your VO₂max and VLamax to predict lactate thresholds (LTP1 and LTP2) to set ENDUROX training zones, and a substrate utilisation profile showing how your body shifts between fat and carbohydrate use at different intensities.
HOW TO ESTIMATE VLAMAX
Running Protocol (HYROX-specific): 1) Resting lactate. 2) Warm-up. 3) 15-second all-out sprint. 4) Lactate samples post-sprint. 5) Cool down.
Cycling Protocol: Similar protocol, performed on a stationary bike.
Enter values into the calculator. VLamax guide: Low (0.2–0.4) for endurance; High (≥0.6) for power.
WHAT IS THE IDEAL VLAMAX FOR HYROX?
Aim low enough for endurance (>0.3, <0.6) to sustain running speeds while retaining power for stations.
HOW TO ESTIMATE VO₂MAX
Use a wearable estimate or derive maximal aerobic velocity (MAV) from it.
HOW THE CALCULATOR WORKS
The tool predicts thresholds (LTP1 and LTP2) and substrate shifts using your VO₂max and VLamax inputs.
PUTTING IT INTO PRACTICE
The calculator reveals your training zones, glycolytic power, and physiology type for HYROX optimisation — helping you tailor sessions to your specific metabolic profile.
