Clinical Question

What are the benefits of regular exercise for adults undergoing maintenance dialysis?

Evidence-Based Answer

Regular exercise probably improves functional capacity for adults undergoing maintenance dialysis and might be associated with small improvements in pain, depression, and quality of life; it is uncertain whether any effect on risk of death or cardiovascular outcomes occurs.¹ (Strength of Recommendation: B, systematic review and meta-analysis of lower-quality clinical trials.)

Practice Pointers

For patients with end-stage renal disease, peritoneal dialysis and hemodialysis can prolong life compared with conservative management. However, dialysis is also associated with a considerable commitment of time, and patients are at risk of discomfort and complications. Up to 60% of patients who initiate dialysis later regret the decision.² A previous Cochrane review found that regular exercise could improve fitness, walking capacity, and health-related quality of life among patients with all stages of chronic kidney disease.³ The authors of this review sought to evaluate the effects of regular structured exercise training on death, cardiovascular events, fatigue, depression, functional capacity, and pain for adults with end-stage renal disease who were undergoing dialysis.

For this review, the authors performed a meta-analysis of 77 studies including 3,846 participants.¹ Three studies included patients on maintenance peritoneal dialysis, four studies included patients on peritoneal dialysis or hemodialysis, and the remaining studies included patients on hemodialysis only. Twenty-six studies were conducted in Europe or the United Kingdom, 22 in North America, 17 in Asia, 10 in the Middle East, eight in South America, four in Oceania, and two in Africa. Participants' mean age ranged from 30 to 72 years, and 62% were male.

The studies in this review included 100 different exercise comparisons lasting between eight weeks and two years (55% of the studies were three months or less). Regimens included aerobic training sessions lasting 10 to 90 minutes, resistance training sessions, combined aerobic and resistance exercises, range of movement exercises, and yoga (one study). Exercise training was completed during dialysis in 65 studies, before or after dialysis sessions in nine studies, and on nondialysis days in 11 studies. In the remaining studies, the timing of exercise was unclear.

The review authors noted that reported outcomes across the included studies were “numerous and disparate.” For the primary outcomes addressed in this review, evidence was insufficient to determine an effect on death (only one death occurred in one study) or cardiovascular events (none were reported in any of the studies). Measures of fatigue differed too greatly across the studies to allow for a pooled estimate of effect, but based on the measures reported in the studies, there is low-certainty evidence that aerobic or resistance exercise reduced fatigue.

Seventeen studies used the 36-item Short-Form Health Survey (SF-36) to measure health-related quality of life. There was low- to very low–certainty evidence that aerobic or resistance exercise might improve physical or mental scores on the SF-36. Measures of pain (15 studies) and depression (11 studies) showed small improvements with aerobic, resistance, and combined exercise, but the small effect sizes and broad CIs mean this finding is of uncertain clinical significance. Moderate-certainty evidence showed that functional capacity—as measured by improvements on the six-minute walk test—probably improved with aerobic exercise (by about 53 m), resistance exercise (by about 45 m), or combined exercise (by about 50 m). Exercise training was also associated with small improvements in performance on two different approaches to sit-to-stand testing.

Based on an earlier Cochrane review,³ Kidney Disease: Improving Global Outcomes guidelines recommend that patients with chronic kidney disease and hypertension participate in moderate-intensity physical activity for 150 minutes per week but note that exercise goals may need to be modified for some patients.⁴ A 2021 guideline from the Renal Association recommends that for patients with end-stage renal disease who are on dialysis, exercise should be performed between and during dialysis sessions and that exercise should be available in all dialysis units.⁵ This Cochrane review demonstrates that even in patients with end-stage renal disease who are on dialysis, exercise probably improves functional capacity and can be undertaken during dialysis sessions.