Aerobic Exercise Prescription in Cardiac Rehabilitation Based on Heart Rate from Talk Test Stages and 6-Minute Walk Test

Background: Although the Talk Test (TT) is a reliable and low-cost test, its use for aerobic exercise prescription is still limited.Objective: To analyze the heart rate (HR) in the stages of the TT and at the peak of the 6-minute walk test (6MWT) as a parameter to prescribe aerobic exercise compared with HR at the first and second ventilatory thresholds (VT1 and VT2) of cardiopulmonary exercise test (CPET).Methods: Individuals with cardiovascular disease attended three assessment days: 1) anamnesis and CPET; 2) 6MWT; and 3) TT. One-way repeated measures ANOVA or Friedman's test were used to compare HR at VT1 and VT2 with HR at TT stages: last positive (TT+), first equivocal (TT +/-), and negative (TT-), and at the peak of the 6MWT. Pearson's or Spearman's test assessed correlations between HR at VTs, TT stages, and 6MWT. Statistical significance was set at 5%.Results: The study included 22 cardiac patients (13 men, 61 +/- 8 years). HR at VT1 was similar to HR at TT+ (p = 0.987) and TT +/- (p = 0.154), and moderately correlated with TT+ (r = 0.479, p = 0.024). HR at VT2 was similar to TT- (p = 0.383), with a strong correlation (r = 0.757, p < 0.001). HR at the peak of the 6MWT was significantly different from HR at TT+, TT +/-, and VT1 (p = 0.001, p = 0.005, and p < 0.001, respectively) but similar to TT- (p = 0.68).Conclusions: HR at TT+ and TT- reflect HR at VT1 and VT2, respectively, differently from 6MWT, which was similar only to VT2. TT may be an objective test to assist aerobic exercise prescription in cardiac rehabilitation.