Table 3. – Methods for prescription of moderate-intensity aerobic exercise.

Method	Description
Rating of perceived exertion (Borg)	Exercises yielding a rating of perceived exertion of 2–4 on the 0–10 Borg scale or 10–13 on the 6–20 Borg scale
Speech test	Exercise intensity maintained so that breathing is labored but still controlled, and the patient is still able to speak a complete sentence without pause
Percent peak HR	Exercise intensity titrated to an HR target of 70–85% of peak HR* Target HR = peak HR x desired percentage
HR reserve (Karvonen)	Exercise intensity titrated to an HR target of 50–85% of reserve HR (peak HR – resting HR). Target HR = resting HR + (peak HR – resting HR) x desired percentage
Cardiopulmonary exercise test thresholds	Exercise intensity titrated to remain between ventilatory threshold 1 (anaerobic threshold) and ventilatory threshold 2 (respiratory compensation point)

*Peak HR preferably measured during a maximal exercise stress test, as interindividual variability can cause errors in the prediction of HR by age, especially in patients who are on medications with negative chronotropic effect. HR: heart rate.