New Study Aims to Improve Cardiac Rehab Through Tailored Exercise Intensity Prescriptions

Quinn Pack, MD, medical director of Cardiac Rehabilitation and Wellness at Baystate Health will serve as principal investigator of a new clinical trial that aims to answer the question “Should I exercise to an intensity that ‘feels good’ or should I get a stress test and exercise to a specific heart rate?”. A direct comparison of these two techniques has never been studied in cardiac rehab before.

What is the Clinical Trial and How Will It Work?

Sponsored by the National Institute of Aging, Improving Outcomes from Cardiac Rehabilitation Among Older Adults Through Exercise Testing and Individualized Exercise Intensity Prescriptions will randomize cardiac rehabilitation patients to receive either usual care techniques or a customized routine that optimizes exercise intensity based on their individual response to exercise testing.
The study hopes to start enrolling patients in early 2023 at Baystate.

Cardiac Rehabilitation Programs and Recovery

Cardiac rehabilitation (CR) is a supervised program that includes prescribed exercise training, education about healthy living, and counseling to find ways to relieve stress and improve mental health. It is an important program for people who’ve had any problem with their heart, such as a heart attack, heart failure, or heart surgery. Unfortunately, many CR programs fail to meet established benchmarks for improving fitness among their patients. Dr. Pack attributes this failure to marked differences in exercise intensity prescription practices across CR programs.

Usual Care Techniques for Cardiac Rehabilitation

The most common usual care technique for prescribing exercise in CR is the use of ratings of perceived exertion (RPE), how hard you feel your body is working based on physical sensations experienced during exercise, combined with an exercise target heart rate of 20-30 beats per minute higher than resting heart rate. While easy to implement, these usual care techniques can lead to lower fitness gains and failure to reach established benchmarks.

Prescribing a Custom Exercise Intensity Program

For the study, Dr. Pack and his team will prescribe a customized exercise routine that optimizes a patient’s exercise intensity based on their individual response to exercise testing. To achieve this, a graded exercise test will be performed on the patients to measure their cardiovascular response to physical activity. Results from the test will be used to formulate an effective and appropriate exercise program. “I have seen across the literature two main ways to prescribe exercise; the first is to exercise until it ‘feels right,’ and the second is to maintain a heart rate in a specific heart rate zone,” says Dr. Pack. “To my knowledge, there has never been an adequately powered, randomized control trial comparing those two methods.”

A Pilot Trial Informs Grant Submission

The study is based on findings from a pilot trial at Baystate Health in October 2020. “We were fortunate to receive a Research Pilot Award Program (RPAP) award from Baystate Health,” adds Dr. Pack. “We are ecstatic that the pilot funding was available, and it allowed us to do some things we would not have been able to do otherwise. The pilot has strongly informed how we wrote the grant and how we plan to administer this randomized trial moving forward.”

Greater Improvements in Fitness

Dr. Pack and his team will measure exercise outcomes, enjoyment, and maintenance during the study with three aims:

1. measure improvements in fitness during CR.
2. assess the impact of individualized exercise intensity prescriptions on psychological factors associated with exercise adherence (self-efficacy and fear).
3. evaluate how the use of individualized exercise intensity prescriptions impacts long-term physical activity, quality of life, fitness, and clinical outcomes.

Ultimately, we anticipate our results will promote evidence-based exercise intensity practices in cardiac rehabilitation programs, leading to greater improvements in fitness, physical activity, and exercise self-efficacy, and more successful aging,” Dr. Pack concludes.