A systems model approach to the ventilatory anaerobic threshold

  • R. Hugh Morton
  • Gregory C. Gass


An analogue systems model of whole-body human bioenergetics predicts a change in kinetics of\(\dot V_{{\text{O}}_{{\text{ 2}}} } \) time series values as a result of exercise levels above an anaerobic threshold. Plotted\(\dot V_{{\text{O}}_{{\text{ 2}}} } \) results from exercising subjects appear to confirm this change. The purpose of this study is to describe the background to the systems model analogue of the anaerobic threshold and a test procedure devised to estimate this threshold. The estimate so obtained has the dual advantages of being based on model theory and of not being subject to the sort of ambient variations inherent in a single-test determination. A non-homogeneous group of eight subjects comprising a full replicate of a 23 factorial experimental design, with factors age, sex and training status, took part in the study. On one hand the results indicate acceptance of the systems model theory. On the other, the analogue threshold measure possesses corresponding properties to the conventional anaerobic threshold. It is higher for trained (155–214 W) than for untrained subjects (108–158 W), higher for males (149–214 W) than for females (108–170 W), and displays no evident interaction effects. Results for the\(\dot V_{{\text{O}}_{{\text{ 2}}} } \) time constant and for the work efficiency, display similar effects except for an interaction in the latter between age and training status. These experimental findings are regarded as confirmatory of the nature of the analogue threshold measure.

Key words

Anaerobic function Cycle ergometer Energy equivalent Exercise test Factorial experiment Maximum power Oxygen uptake Time constant Work efficiency 


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Copyright information

© Springer-Verlag 1987

Authors and Affiliations

  • R. Hugh Morton
    • 1
  • Gregory C. Gass
    • 2
  1. 1.Mathematics and Statistics DepartmentMassey UniversityPalmerston NorthNew Zealand
  2. 2.Department of Biological SciencesCumberland College of Health SciencesLidcombeAustralia

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