Validity of the Talk Test as a Method to Estimate Ventilatory Threshold and Guide Exercise Intensity in Cardiac Patients

Purpose: To determine the relationship between the Talk Test (TT) and ventilatory threshold (VT) in patients with cardiac disease and to compare the TT with exercise intensity guidelines. Methods: Twenty cardiac patients, aged 65 +/- 8.5 yr, performed 2 exercise tests with identical ramp protocols on a cycle ergometer on the same day. One test was a submaximal effort to assess exercise intensity using the TT. The other was a cardiopulmonary exercise test using breath-by-breath gas analysis to identify VT and cardiorespiratory fitness. Results: Oxygen uptake ((V) over doto(2)) and workload at the last positive stage (TTpos) was significantly lower than at VT. (V) over doto(2) and workload at the equivocal stage (TTeq) and the first negative stage (TTneg) were not significantly different from VT, but limits of agreement (LoA) were wide. There was no significant difference in heart rate (HR) at TTpos and TTeq compared with VT, but HR at T-neg was significantly higher. The correlations between the TT and VT ranged from 0.37 to 0.60. Intensity at the different TT stages ranged from 58-77% of (V) over doto(2). All TT stages were within intensity guidelines of 40-80% of (V) over doto(2). Conclusion: Although no significant differences were found in (V) over doto(2) and workload for TTeq and TTneg when compared with VT, LoA demonstrated wide ranges, suggesting poor individual correspondence. The different stages of the TT can be used as a practical method to guide exercise intensity in patients with cardiac disease.