RESUMO
PURPOSE: Correlative data have suggested that the Talk Test (TT) may be a surrogate of the ventilatory threshold (VT). This study examined manipulations of either the VT or exercise protocol to test the hypothesis that the TT and VT are related in a robust way, adequate for exercise prescription. METHODS: Healthy young adults participated in 4 independent series of experiments designed to decrease (blood donation) or increase (training) VT, or to systematically vary the exercise intensity above and below VT. These interventions were matched to responses of the TT. RESULTS: The changes in the exercise intensity at VT and at the last positive stage of the TT matched each other following both blood donation and training. When exercise intensity was varied above and below VT, the predicted ability to speak was well matched to observations of the TT. Predictive errors biased toward passing the TT when exercise intensity was greater than VT. The time required for the result of TT to become negative when exercise intensity was more than VT, decreased with increasing intensity but averaged more than the 2 minutes that has been used in previous studies. CONCLUSIONS: This study confirms the robust relationship between VT and the TT during various interventions and suggests that the TT is suitable for exercise prescription.