According to the guidelines, what is true regarding the intensity of exercise after myocardial infarction?

The guideline stating that exercise intensity should gradually increase based on symptoms is grounded in principles of safety and individualization following a myocardial infarction. After such an event, patients may have varying levels of physical fitness and different responses to exercise due to their condition.

Starting at a moderate intensity and progressively increasing the workload allows for careful monitoring of the individual’s response to exercise. This approach helps to prevent undue stress on the heart, reduces the risk of complications, and ensures that the patient can handle the intensity without adverse effects. The focus is on building endurance and fitness safely, considering each patient's unique situation and symptoms during the recovery process.

In contrast, the other options suggest starting high intensity or operating at maximal heart rates, which are not safe and could lead to significant risks, and the notion of exercising without supervision could compromise the patient's safety and recovery monitoring.