VLamax, VO2max, FTP: The Truth About the Three Key Aerobic Metrics

Introduction

The most familiar metric for amateur cyclists is FTP (Functional Threshold Power), but elite training science has long moved beyond the era of single metrics. VLamax, promoted by the German INSCYD system, together with the classic VO2max and FTP, forms the three pillars of modern aerobic capacity.

Definitions of the Three Metrics

The Mathematical Relationship Between the Three

The core equation of INSCYD is conceptually:

FTP ≈ VO2max × Economy − VLamax × Buffering Coefficient

This means:

• The higher the VO2max, the higher the aerobic ceiling → the higher the FTP
• The higher the VLamax, the stronger the anaerobic glycolysis → the faster lactate accumulates → the lower the FTP
• At the same VO2max, the lower the VLamax, the higher the FTP

Ideal Combinations for Different Disciplines

How to Train Each Metric?

• Improve VO2max: 3–5 minute Z5 intervals (e.g., 5×4 min @ 110–115% FTP)
• Lower VLamax: Long-duration Z2 + limiting anaerobic expenditure, Fat-Max training
• Improve FTP: Threshold workouts, SST, Over-Under

Note: Sprint explosive training will raise VLamax, which is actually detrimental for pure endurance riders.

Research Background

Mader and Heck established the mathematical model of lactate kinetics in the 1980s, laying the foundation for the VLamax concept. Faude, Pyne, and others subsequently validated the negative impact of VLamax on endurance performance. INSCYD commercialized it, making it a standard testing tool for many World Tour teams.

Practical Advice

• Amateur endurance riders: prioritize “lower VLamax + raise VO2max,” and do fewer pure sprint workouts
• Sprint-type riders: maintain VLamax, focus on improving VO2max and recovery capacity
• No need to undergo formal INSCYD testing, but understand the concept that “higher FTP is not always better”
• Observe whether you are “strong anaerobically but fade quickly over long distances” → this may indicate VLamax is too high

Conclusion

FTP is just the tip of the iceberg. Once you truly understand the relationship between VLamax and VO2max, you will design your training more precisely: what to train, what to avoid, and what is contradictory. Taiwanese cyclists love short climbs and sprint-finish culture, but this often keeps VLamax persistently high, limiting long-distance performance.

Related Reading

• Fitness Test Data Analysis: Tracking Progress with VO2max, FTP, and PWR
• The Complete Guide to VO2max Interval Training: How to Break Through Your Maximal Oxygen Uptake Ceiling
• VO2max Power Training: Workout Design and Recovery Management for 120% FTP Intervals
• VO2max Power Intervals: Designing 3–8 Minute High-Intensity Workouts