Introduction
HD, attention deficits, CKD, chronic kidney disease
Patients with chronic kidney disease (CKD) treated with hemodialysis (HD) experience a decline in physical function and mobility, including difficulties with walking, balance, and coordination [A physical exercise intervention showed to be effective in improving physical performance in HD patients [On the other hand, while existing literature suggests a positive effect of physical exercise on cognitive function, there is a lack of high-quality randomized controlled trial data and inconsistencies in the available evidence. Generally, the number of studies examining the effects of non-pharmacological interventions on cognitive function is low in HD population and they mostly involved interventions in the form of physical exercise. A walking program in HD patients showed an improvement in self-reported cognitive function [Assuming that both physical exercise and cognitive training have promising effects on cognitive performance in HD patients, it would be worthwhile to combine them. Therefore, the objective of this study was to examine the effects of cognitive training in conjunction with intradialytic cycling on cognitive and physical performance of dialysis patients. Considering that HD patients have significant attention deficits and physical performance deficits with reduced mobility, we chose attention cognitive domain and spontaneous gait speed (SGS) as key outcome variables. We hypothesized that the combination of cognitive and physical exercise interventions will reduce attention deficits and enhance gait speed, or at minimum, prevent the decline of these performance measures in a representative sample of dialysis patients.