VT1 and VT2 in a VO2 Max test - Why they are important
VT1 and VT2 in a VO2 Max Test
When performing a VO2 max test, two key ventilatory thresholds are identified: VT1 (First Ventilatory Threshold) and VT2 (Second Ventilatory Threshold). These thresholds indicate shifts in how your body utilizes energy and can help guide training zones effectively.
A MaxVO2 test it so much more than just knowing what your upper limit is. Its about understanding the metabolic journey your body goes through on the way there helping you to strategically maximise your training efforts and minimise your risk of injury. By knowing your VT1 and VT2, you can structure workouts to maximize endurance, efficiency, and race performance.
VT1 (First Ventilatory Threshold)
What It Measures: VT1 is the point where ventilation starts to increase disproportionately to oxygen consumption due to an increase in blood lactate levels. This happens as the body begins relying more on anaerobic metabolism for energy.
Physiological Meaning:
Marks the transition from light to moderate intensity.
Associated with the lactate threshold (LT1), where lactate starts to accumulate slightly but can still be cleared effectively.
You can still talk comfortably but may notice breathing becoming a bit deeper.
Training Implications:
Training below VT1 (Zone 1) is great for aerobic base building and recovery.
Training at or just above VT1 (Zone 2) improves fat oxidation and endurance.
VT2 (Second Ventilatory Threshold)
What It Measures: VT2 is the point where ventilation increases even more sharply due to a rapid rise in lactate accumulation. This is where the body can no longer clear lactate efficiently, leading to metabolic acidosis.
Physiological Meaning:
Marks the transition from moderate to high intensity exercise.
Corresponds closely to the lactate turn point (LT2), where lactate production exceeds clearance.
You can no longer speak in full sentences due to heavy breathing.
Training Implications:
Training near VT2 (Zone 3) improves lactate tolerance and high-intensity endurance.
Training above VT2 (Zone 4-5) focuses on anaerobic power and VO2 max development.
Practical Applications for Training
Base Training (Below VT1, Zone 1-2): Build endurance and improve fat utilization.
Threshold Training (Between VT1 and VT2, Zone 3): Improve lactate clearance and sustain higher intensity efforts.
High-Intensity Training (Above VT2, Zone 4-5): Develop VO2 max and anaerobic capacity.