Evolution in peak oxygen uptake and its impact on physical activities of daily living in chronic kidney disease and transplantation.

This viewpoint aims to characterise the evolution of peak oxygen uptake (V̇Opeak) in chronic kidney disease (CKD), describe its impact on patients' ability to engage in physical activities of daily living and frame the meaningfulness of exercise training in this respect. Analysis of literature data from 4889 patients shows that per cent-predicted V̇Opeak decreases from 69%±10% at CKD stage 2 to 51%±9% at CKD stage 5, before partially recovering to 60%±12% beyond 12 months post-transplant. Similarly, V̇Opeak expressed as oxygen uptake relative to body weight decreases from 24.7±4.1 to 18.0±3.4 mL/kg/min across CKD stage 2-5, with a partial recovery to 21.6±4.9 mL/kg/min beyond 12 months post-transplant. Considerable variability exists in reported V̇Opeak levels at each of the different disease stages. In a substantial proportion of patients, impaired cardiorespiratory fitness contributes to limitations in performing common physical activities such as brisk walking, carrying groceries upstairs, mowing the lawn or engaging in vigorous play with (grand-)children. Tailored exercise training can improve cardiorespiratory fitness and enable a meaningful increase in the ability to participate in a wider range of physical activities of daily living; a powerful message to incentivise patients.