Let’s first make it clear that you should talk to your physician before changing your workout routine, particularly if you have a heart condition.
That said, some studies suggest that a higher intensity interval workout routine, such as those used by athletes, may be beneficial for patients with heart conditions.
High intensity interval training involves short bursts of intense exercise at 85-95 percent maximum heart rate. These short bursts are alternated with periods of moderate exercise. This workout method is frequently used by athletes to improve speed and endurance.
This is a different approach than what has been traditionally recommended for heart patients, which has generally been a protocol of steady aerobic exercise at 70 percent maximum heart rate. This lower level of intensity is intended to work the heart without risking chest pain, heart attack, or other complications.
There is no agreement on whether high intensity interval exercise should be used to treat heart patients who have suffered heart failure, are recovering from bypass surgery, or are living with coronary artery disease. Recent studies, however, have suggested that an exercise routine that includes high intensity interval training improves the body's ability to transport oxygen more than a lower intensity workout.
For example, a Norwegian study looked at the effects of a supervised high intensity treadmill workout on cardiac rehab patients. Results showed improved peak oxygen that was better than the results from the standard approach.
The Mayo Clinic started using high intensity interval training back in 2007 and may be one of the few clinics in the United States to do so early on in cardiac rehab.
The method used is to gradually work patients up to 20 minutes of exercise at a moderate pace, typically on a treadmill. Then they engage in 30-second bursts of higher intensity exercise, such as by increasing the incline and the pace. Eventually intervals are increased to 120 seconds in length.
According to the Mayo Clinic, there are patients for whom this form of training would not be appropriate, such as those suffering from chronic angina.
The American Heart Association has recommended that larger controlled studies be done with high-risk groups. Other studies are also looking at the impact of high intensity interval training in individuals with high blood pressure and diabetes.
One thing to remember is the exercise intensity that equals 85 to 95 percent maximum heart rate differs from person to person. For an athlete, it may take a sprint to work the heart up to this level, but for someone recovering from bypass surgery it may require just a short walk. You start with where you are and work your way up.