Date of Award

1991

Degree Type

Thesis

Degree Name

Bachelor of Applied Sciences Honours

Faculty

Faculty of Science and Technology

First Advisor

Michael Ponchard

Abstract

A study which assessed the validity of the Conconi test to predict the anaerobic threshold (AnT) was undertaken with 20 sport science students. The study involved the subjects undertaking three tests over a one week period. Each test was separated by a period of at least 48 hours which allowed the subjects time to recover. The subjects initially completed a Conconi test which attempted to predict their AnT through plotting heart rate against work intensity. Following the specified recovery, a maximum oxygen uptake test (V02max) was undertaken by all subjects. Following another recovery period those subjects who produced a deflection point in the Conconi test performed a prolonged cycle at the Conconi-predicted AnT. Serial lactate measurements were taken at 5-minute intervals during the prolonged cycle in order to determine whether a steady state lactate response resulted. Thirty five percent of the subjects failed to produce deflections in the Conconi test. Clinical analysis of the lactate data identified that only 25 % of the remaining subjects produced steady state lactate responses during the prolonged cycle. The findings of the clinical analysis were supported by applying a repeated measures ANOVA to those subjects. All other subjects failed to complete the prolonged cycle and to produce steady state lactate responses. Two subgroups were identified from the subjects who produced deflection points in the Conconi test. A t-test revealed that the two identified subgroups were significantly different. One group deflected at exercise intensities under 85 % V02max while the other deflected at over 85 % V02max. Three hypotheses were tested during the study. The first hypothesis stated that the Conconi test would overestimate the anaerobic threshold (AnT), causing blood lactate concentrations to rise continuously in all subjects over the duration of a prolonged cycle at the Conconi-predicted AnT. The second hypothesis stated that each subject's oxygen consumption value measured at the deflection point during the Conconi test would correspond to an intensity greater than 85 % of their VO2max. The final hypothesis stated that all subjects would produce a heart rate deflection during execution of the Conconi test. The three proposed hypotheses were rejected. The results concluded that the Conconi test was an invalid predictor of the AnT. Based on the results of this study the following conclusions were reached: a) the Conconi test will not produce deflection points in all subjects, b) the exercise intensity predicted by the Conconi test will not produce lactate steady state responses in all subjects, and c) the Conconi-Predicted AnT does not correspond to an exercise intensity above 85 % VO2max in all subjects.

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