Exercise works!

Exercise is effective for patients with ESRD6—it increases maximal oxygen uptake capacity, improves blood-pressure control, decreases arterial stiffness, decreases systemic inflammation, improves solute removal by dialysis, increases muscle force, and augments perceived quality of life (QoL). Beyond outstanding issues regarding the precise exercise prescription (endurance vs resistance training), the critical question is not whether to include exercise programmes in the standard care of haemodialysis patients with ESRD, but why you would not. Therefore, I invite all nephrologists and medical professionals to promote, prescribe and, especially, plan long-term, intradialytic exercise programmes in their units, regardless of patient age. Here are some arguments for adequate exercise training in patients with ESRD, with a special focus on children and malnourished older adults.

Addressing major misconceptions about the young and the old

A major misconception is the issue of the feasibility, acceptability and safety of an intradialytic cycling programme in a population of children or older adults on haemodialysis. A recent study showed that a 3-month exercise programme of intradialytic cycling (30 min sessions, 2–3 times a week) is feasible, free from adverse effects, and well tolerated by paediatric patients (age range 9.1–24.2 years).4 Considering the challenge of providing optimal haemodialysis to children with ESRD,7 their positive feedback on the intradialytic cycling programme has interesting implications, starting with an increase in the acceptance of haemodialysis therapy and a possible means of improving their long-term outcomes.4 ,7 Similar conclusions can be drawn from studies of frail older haemodialysis patients, especially those with protein–energy wasting (PEW), for whom prevention and treatment aim to replenish protein and energy stores and stimulate anabolic processes. Few dialysis centres currently offer exercise training programmes to older patients (over-represented in the dialysis population)6 as a new therapeutic complement. Yet, robust arguments support the fundamental and clinical value of prescribing exercise to patients with PEW, along with nutritional interventions, to enhance the anabolic effects of nutrition and thereby reverse this high-risk state. A recent randomised controlled trial (RCT) showed that a 6-month intradialytic exercise programme, combined with nutritional support, was safe, free from noticeable adverse effects, well tolerated, and accepted by older patients with PEW (mean age 69.7±14.2 years). In addition, the nutrition and exercise group (vs the nutrition group) showed an improvement in the 6 min walk test (+22%), an absence of decline in balance mechanisms (unlike the nutrition group), and a noteworthy increase in self-reported physical health dimensions of QoL (+53%).5

Interestingly, another advantage of intradialytic exercise is the excellent compliance (87.7% of realised sessions). Effective improvements in physical function contribute to prevention of some clinical and functional disabilities. QoL scores accurately predict hospitalisations and mortality.8 Similarly, a significant bimonthly progression of the training parameters, such as distance covered when cycling (∼103.8±46.74 km/month) and cycling duration (∼355.03±95.95 min/month), provides other convincing evidence of better physical autonomy in these older patients. Importantly, all patients in the exercise group said that they hoped to continue cycling after the end of the study. They reported a feeling of well-being and that dialysis sessions were less boring and a better experience. An unexpected but encouraging consequence was the demand for similar interventions from the control group, and even from other older haemodialysis patients that were not eligible for the RCT.

A call to action

When combined, these modest findings indicate the effectiveness of exercise training for haemodialysis patients, whether children or young or older adults. Exercise training should be standard practice in the care of haemodialysis patients. Beyond the feasibility of implementing exercise programmes for these specific populations, the beneficial effects are clinically crucial. They offer a more attractive bridge to someone awaiting a future transplant.

Collectively, let us not hesitate to change our routines and programme intradialytic exercise for haemodialysis patients, regardless of age! For future RCTs necessary to provide the main outcome measures, a reasonable and reasoned ambitious Big Data Clinical Trial will reshape the profiles of clinical research in nephrology.