Validity and reliability of combining three methods to determine ventilatory threshold

Med Sci Sports Exerc. 2001 Nov;33(11):1841-8. doi: 10.1097/00005768-200111000-00007.


Purpose: This research was undertaken to validate a combination of methodologies to determine ventilatory threshold (VT).

Methods: Three methods were used individually and then combined to determine VT as follows: 1) ventilatory equivalencies, 2) excess CO2 production, and 3) a modified V-slope method. Three groups of participants-endurance athletes (N = 132), healthy, aerobically active adults (N = 31), and healthy, sedentary/low-active adults (N = 22)-were independently evaluated for VT and compared with the criterion standard lactate threshold (LT) defined as the first rise in blood lactate with increasing intensity of exercise.

Results: VT and LT were significantly correlated using the combined VT method within each study group (r = 0.98, 0.97, and 0.95, respectively; P < 0.001). Mean VO2 values at VT and LT were not significantly different between the three groups (P > 0.20). The combined method improved the determination rate of VT and reduced the standard deviation of the LT - VT difference by 80-170% over the individual methods. During test-retest procedures VO2lt and VO2vt determined by the combined method met criteria demonstrating further reliability.

Conclusion: The combined method to determine VT is valid and reliable across a wide fitness range in healthy individuals and improves the determination rate and accuracy of VT determination over the use of single methods.

Publication types

  • Validation Study

MeSH terms

  • Adult
  • Anaerobic Threshold*
  • Analysis of Variance
  • Carbon Dioxide / metabolism
  • Exercise Test / methods*
  • Exercise Test / standards
  • Female
  • Humans
  • Lactic Acid / blood
  • Life Style
  • Male
  • Oxygen Consumption*
  • Physical Fitness / physiology*
  • Reproducibility of Results
  • Respiration
  • Sports / physiology


  • Carbon Dioxide
  • Lactic Acid