Gentler treadmill protocols, with incre- mental stages of 1 MET, or bicycle stress can help some patients achieve maximal exercise capacity. Optimal candidates with sufficient physical functioning may be identified as those capable of performing at least moderate physical functioning (ie, performing at least mod- erate household, yard, or recreational work and most activi- ties of daily living) and with no disabling comorbidity (including frailty, advanced age, marked obesity, PAD, chronic obstructive pulmonary disease, or orthopedic limita- tions). Patients incapable of at least moderate physical func- tioning or with disabling comorbidity should be referred for pharmacological stress imaging. In the setting of submaximal exercise and a negative stress ECG, consideration should be given to performing additional testing with pharmacological stress imaging to evaluate for inducible ischemia. 2.2.1.4. Concomitant Diagnosis of SIHD and Assessment of Risk Although the primary goal of testing among patients with new onset of symptoms suggesting SIHD is to diagnose or exclude obstructive CAD, the various modalities also can provide additional information about long-term risk (Section 3.3.2), and this prognostic ability may influence the selection of an initial test. Exercise capacity remains one of the strongest indicators of long-term risk (including death) for men and women with suspected and known CAD.118,123 125 In addition, information derived from treadmill exercise (eg, Duke treadmill score126,127 and heart rate recovery) provides incremental diagnostic and prognostic information. For this reason, it is preferable to perform exercise stress if the patient is able to achieve a maximal workload. For the exercise- capable patient with a normal baseline ECG, the decision to perform imaging with nuclear or echocardiographic tech- niques along with stress ECG should be based on many factors, including the likelihood of garnering substantial incremental prognostic information that is likely to alter clinical and therapeutic management. 