Consistency of the talk test for exercise prescription

The Talk Test has been shown to be well correlated with the ventilatory threshold, with accepted guidelines for exercise prescription, and with the ischemic threshold. As such, it appears to be a valuable although quite simple method of exercise prescription. In this study, we evaluate the consistency of the Talk Test by comparing responses during different modes of exercise.

Healthy volunteers (N = 16) performed incremental exercise, on both treadmill and cycle ergometer. Trials were performed with respiratory gas exchange and while performing the Talk Test. Comparisons were made regarding the correspondence of the last positive, equivocal, and first negative stages of the Talk Test with ventilatory threshold.

The %VO2peak, %VO2 reserve, %HRpeak, and %HR reserve at ventilatory threshold on treadmill versus cycle ergometer (77%, 75%. 89%, and 84% vs 67%, 64%, 82%, and 74%) were not significantly different than the equivocal stage of the Talk Test (83%, 82%, 86%, and 80% vs 73%, 70%, 87%, and 81%). The VO2 at ventilatory threshold and the last positive, equivocal and negative stages of the Talk Test were well correlated during treadmill and cycle ergometer exercise.

The results support the hypothesis that the Talk Test approximates ventilatory threshold on both treadmill and cycle. At the point where speech first became difficult, exercise intensity was almost exactly equivalent to ventilatory threshold. When speech was not comfortable, exercise intensity was consistently above ventilatory threshold. These results suggest that the Talk Test may be a highly consistent method of exercise prescription.