['To assess relative reliability and measurement error of the Graded Cycling Test (GCT) with the Talk Test (TT) for patients with cardiac disease.', 'Patients (N = 64; women, n = 30) with ischemic heart disease performed the GCT with the TT twice in 1 day. Every minute the patient recited a text passage of 30 words. The question "Are you still able to speak comfortably?" was then answered: "Yes" (TT+), "Not sure" (TT±), or "No" (TT-). Two physiotherapists (PTs) rated when the speaking ability was affected by ventilation. Relative reliability: intraclass correlation coefficient (ICC)2.1 and absolute reliability: standard error of measurement with 95% CI (SEM95) and smallest real difference (SRD) were calculated.', 'Intraclass correlation coefficient values of 0.90, 0.91, and 0.90 were observed for TT+, TT±, and TT-, respectively. Physiotherapist ICCs ranged between 0.81 and 0.88. SEM95 ranged between 17.2 and 18.3 watts (W), with corresponding SRD values between 24.4 and 25.9 W for the patient ratings. The PT ratings ranged between 15.8 and 21.4 W (SEM95) and between 22.3 and 30.3 W (SRD).'] Is the graded cycling test combined with the talk test reliable for patients with ischemic heart disease?