Ventilatory Threshold (VT1/VT2) Calculator

Ventilatory Thresholds (VT1/VT2): Explanation and Clinical Context Ventilatory thresholds are critical markers in cardiopulmonary exercise testing (CPET) to guide exercise prescription and assess cardiovascular fitness. VT1, the aerobic threshold, represents the exercise intensity at which lactate begins to accumulate above baseline, corresponding approximately to 60% of VO₂ peak. VT2, the anaerobic threshold, indicates a higher intensity where lactate accumulation accelerates rapidly, usually around 80% of VO₂ peak.

Heart rate at these thresholds provides a practical measure for individualized training zones in both healthy and clinical populations. These thresholds help clinicians predict exercise tolerance, identify subclinical cardiovascular limitations, and stratify risk in cardiac and pulmonary disease.