7. What Can the Literature Tell Us About the Optimal Exercise Programme?
In order to design successful exercise program- ous intervention was under study and because themes that will be accessible and acceptable to large numbers of patients with CKD, it is important to know what types of exercise produce the greatest clinical benefit in this population and what types of training programmes can recruit and retain large numbers of patients on dialysis. Much of this work has yet to be done, but some information can be gleaned from the available literature. As for comparisons of the benefits of different programmes, little is known. Konstantinidou et al.[69] compared the effects of centre-based training to those of dialysis unit-based and home-based training on ˙VO2peak. They reported a higher dropout rate among the patients assigned to incentre training and cited lack of time, transportation difficulties and medical reasons unrelated to exercise as the reasons. The patients benefited from all three types of training, but the cardiovascular effects were greatest with the centrebased training. The authors concluded that intense exercise training on non-dialysis days is the most effective way of training. However, this conclusion should be tempered somewhat because it only refers to exercise-induced changes in ˙VO2peak and not other potential benefits. Furthermore, the exercise interventions were so different in the three groups that it is uncertain whether the differences in ˙VO2peak were related to different intensities of training, different activities used for training, or different levels of adherence to the programme since adherence to the home training was not monitored. There is a great need for systematic comparison of the effects of different exercise interventions on out comes of interest to patients with CKD and their healthcare providers, including physical performance, self-reported physical functioning and HR-QOL. More concrete information about benefits that affect QOL should help motivate providers to recommend exercise more enthusiastically and patients to adopt it. However, it is also important to understand what types of exercise are most acceptable to patients.
Many of the studies of exercise training in parelatively healthy subset of the population. In some cases, this was by design because a relatively vigorous intervention was under study and because the goal was to test whether the healthiest group of patients could demonstrate an effect of training. However, it is also clear that it is difficult to enlist patients with CKD into exercise programmes.
Shalom et al. [7] were one of the first groups to report on the number of patients excluded from study participation. They planned an in-centre, supervised aerobic training programme to be performed on non-dialysis days. Of 174 patients on dialysis, 70 (40%) lived too far away to participate, and 54 (31%) were excluded because of coexistent medical problems. Consequently only 50 patients (29%) remained eligible for participation. Although all were offered the chance to participate, only 14 actually enrolled. Of those who enrolled in the exercise programme, only 50% attended more than half of the training sessions. These data highlight two problems with implementation of widespread exercise programmes for patients on dialysis. First, a large number of patients were excluded for medical reasons because the planned intervention was a vigorous training programme. Secondly, because the training was to occur in an exercise facility on non dialysis days, geographic considerations limited participation by many patients, and most of those who did not live a prohibitive distance from the centre still found the burden of additional visits for exercise training to be too high.