2.1.6. Choice of the Individual Protocol

The choice of an appropriate protocol is essential. Depending on their intensity, exercise tests can be maximal (symptom-limited) or submaximal (predefined).

In cardiac rehabilitation settings, maximal tests are typically preferred. Indicators of maximal stress test include [11]:



**Table 5.** Veterans Specific Activity Questionnaire.

Source: Adapted from [11].

The submaximal test is terminated after achieving a goal, e.g., in patients < 40 years after myocardial infarction, the test may be terminated after achieving a heart rate of 140 bpm or tolerance equal to 7 METS. In patients > 40 years, the test can be terminated at 130 bpm or at a tolerance of 5 METS. Submaximal tests are traditionally conducted in the early phase after myocardial infarction following cardiac surgery and in patients with impaired left ventricular systolic function. Optimally, the test should be terminated after between 8 and 12 min.

The stress test can be graded (GXT) or ramped (with a constant load increase). Ramp tests demonstrate a good linear correlation between the load and the maximal oxygen consumption [12,13]. Ramp protocols provide a uniform hemodynamic response and therefore can be individualized. Considering recent studies, however, a delay of the initial oxygen uptake response upon the start of the incremental exercise test compared with constant work has been demonstrated. Thus, the first and the second ventilatory thresholds are attained at lower work rates during the constant

work test for a given oxygen uptake value than they are during the incremental test [14].
