top of page
Search

Why ventilatory thresholds (VT1/VT2) predict performance better than lactate thresholds

For decades, lactate tests have been used to assess endurance performance. However, recent research shows that ventilatory thresholds , VT1 and VT2, are often more reliable , more reproducible, and more predictive of actual performance—especially in the field.


This is why breathing has become a central indicator for understanding — and improving — athletic performance.


1. Ventilatory thresholds are directly linked to energy pathways


VT1 and VT2 correspond to specific metabolic transitions:

  • VT1 : initial increase in ventilation to compensate for the CO₂ produced → entry into the tempo zone.

  • VT2 : strong and disproportionate rise in ventilation → compensation for acidosis → critical threshold.


These transitions show exactly how your internal engine reacts to effort.


👉 Unlike lactate, respiration reacts instantly to metabolic needs.



2. Lactate thresholds are very sensitive to external conditions


A lactate measurement can vary depending on:

  • the temperature,

  • nutrition before the test

  • stress or sleep,

  • hydration,

  • altitude,

  • the protocol used (stages too short, too long…).


Even in trained athletes, two lactate tests a few days apart can give different thresholds .


👉 Ventilatory thresholds, on the other hand, are much more stable and reproducible .


Studies (Weston 2001, Pallares 2016) show intra-athlete correlations r> 0.90 for VT1/VT2.


3. Ventilatory thresholds reflect the actual internal load


Breathing is directly regulated by CO₂ and blood acidity. When your breathing becomes rapid:

✔ Your tolerance to acidosis decreases

✔ The anaerobic pathway takes over

✔ Your time in the elevated zone becomes limited


Lactate measures one result of this imbalance. Ventilation measures the ongoing physiological process .


👉 VT2 predicts much better the ability to sustain an effort close to the threshold.


4. VT2 better predicts on-field performance


Research by Poole & Jones (2021), Wasserman, and others shows:

  • VT2 is strongly correlated with performance time over 10 km, cycling, triathlon.

  • VT2 evolves rapidly with training → progress indicator.

  • The shift in VT2 corresponds to a real physiological improvement , not just to better lactate tolerance.


In endurance sports, performing = holding high, for a long time → and that's exactly what VT2 measures.



5. The breathing test is easier… and much more common


The lactate test requires:

  • specific equipment

  • blood samples,

  • a strict protocol,

  • hygiene constraints,

  • a controlled environment.


Conversely, a respiratory test can be performed:

✔ on a home trainer

✔ outdoors

✔ uphill

✔ in the race

✔ at every training session


With ZoneX, ventilatory transitions are detected in real time , without masks and without cumbersome testing.


6. Why this changes everything for training


By using VT1/VT2 as a training basis, the athlete gains access to:

  • more precise pacing,

  • optimal effort management on the climb,

  • improved respiratory stability

  • real-time monitoring of internal workload,

  • a precise view of the progress.


It is a more individualized, less variable and better adapted approach to the terrain than traditional lactic methods.


Conclusion


Lactate thresholds remain useful in the laboratory, but:

👉 Ventilatory thresholds (VT1/VT2) are more stable, more predictive and more representative of the reality on the ground.


With ZoneX, this respiratory power becomes accessible on every outing, without a mask or sampling, to train smarter — and perform better.



More information:

Comments

bottom of page