Importance of Resistance Training for Patients After a Cardiac Event

After a myocardial infarction (MI), percutaneous coronary intervention, or angina pectoris, patients receive conflicting advice from physicians about the level of activity that is acceptable. Most are told that they should not lift anything >5 pounds. When we conducted an informal survey of 28 patients from the Cardiac Rehabilitation Department at the Baylor Jack and Jane Hamilton Heart and Vascular Hospital, patients also recollected advice such as not to lift >10 pounds “for a while,” not to lift anything for a week, not to drive more than 30 minutes, not to “get exhausted” for a month, not to exercise for a few weeks, and not to lift >25 pounds for a period of time—or ever. These guidelines are not only confusing but can also promote fear and inactivity. Further complicating the scenario is that while physicians typically prescribe aerobic exercise—and particularly walking—for the purpose of avoiding further heart complications, patients are more interested in being able to return to activities of daily living, such as mowing the lawn, lifting grandchildren, or vacuuming. The resistance training that would lead to that outcome is rarely prescribed. Exercise physiologists, cardiac rehabilitation professionals, and personal trainers focus on three principles in training. One such principle is specificity. This principle indicates that the training effect is limited to the muscle fibers involved in the activity. For example, mitochondria adapt to endurance training, and contractile proteins adapt to resistance training. It is not reasonable to expect the arms to become trained during a 10-weekjogging program, for example(1). When the specificity principle was applied to football, coaches moved from mile runs for training to 100-yard runs, simulating the longest distance a player would run in competition. The other two principles of fitness training are overload, which states that for a training effect to occur, a tissue must be challenged with an intensity, duration, or frequency to which it is not accustomed; and reversibility, which states that training gains are quickly lost when the overload is removed (1). Over time, positive gains have been made in motivating patients to become more active following MI. Just 40 years ago, patients were put on bedrest for 4 to 6 weeks after an MI. Since then, it has been shown that after just a few days or weeks of bedrest, the patient experiences decreased cardiorespiratory fitness, strength, and flexibility (2). While physicians now acknowledge the value of exercise in cardiac rehabilitation, they have been hesitant to allow resistance training. Part of the problem is the existing guidelines (Table ​(Table11). In our opinion, these guidelines not only delay resistance training unnecessarily but also prescribe weight amounts that are below what patients need for even the most basic activities of daily living. We argue that resistance training should be promoted following the principle of specificity—that is, based on the fact that most patients set goals not to run a 10-kilometer race or to go mountain biking but rather to rise from the bathtub or mow the lawn. The constraints faced in cardiac rehabilitation, from physician prescriptions and from the guidelines, are particularly worrisome, since in society today we seem to place more importance on specifically training athletes (cyclists, marathon runners, football players) than we do on appropriately preparing patients to safely perform everyday activities. This limitation has become particularly obvious as cardiac rehabilitation patients have become younger. Some of these patients need to return to firefighting, police work, or other physically stressful jobs. Table 1 Cardiac rehabilitation resistance training guidelines by diagnosis∗ Our reasons for promoting resistance training are presented below.