A Critical Review of Exercise Training in Hemodialysis Patients: Personalized Activity Prescriptions Are Needed

Abstract

Exercise training appears to have modest or inconsistent benefits in hemodialysis patients. This may be due to the low volume and intensity of exercise often prescribed. To address this, research is needed to evaluate the efficacy of individualized exercise prescriptions as a component of a comprehensive lifestyle intervention strategy that gives patients more autonomy to choose preferred types of physical activity.

Figure 1

To date, most exercise programs for hemodialysis patients have included a mandated activity prescription consisting of a single type of exercise performed either during dialysis or outside of the clinic, with intradialytic cycling being the predominant exercise mode (A). A few interventions have combined aerobic and resistance training, and some have included a nutritional supplement. While each of these types of activities or programs have merit as a component of a larger exercise/physical activity prescription, the benefits of these simplistic prescriptions have been modest at best, and it is clear that novel approaches are needed. A more comprehensive approach (B) is needed to address the plethora of co-morbid conditions that have reduced the efficacy of exercise in many past studies. The individual components of this more comprehensive approach may vary significantly for any clinic, but specific principles should apply. For example, patients should be provided the autonomy to choose types of activities they prefer to engage in, instead of being prescribed specific activities. Intradialytic exercise should be included as a valuable component of an overall physical activity program when resources allow but should not be considered the primary mode of activity. A long-term goal should be to progress all patients towards standard physical activity guidelines, as appropriate for an individual. The ability to implement this type of comprehensive strategy will require tremendous effort and coordination between the clinic staff and exercise specialists who will be needed to facilitate the program. Efforts also should be made to engage the patient’s family or caregivers. Modified nutritional approaches are needed to address factors such as malnutrition, chronic volume overload, and anemia in order to get patients “healthy” enough to increase their physical activity levels. While the challenges are many, the potential benefits are tremendous. This comprehensive approach will require a culture change in which physical activity is prioritized as a component of the standard of care in HD clinics.