Sample size
The sample size was calculated by NCSS PASS 16.0 software. The model was established according to the log-rank test of survival analysis (bilateral side), with α = 0.05 and power 1 – β = 0.8. Due to the fact that there had been no prior randomized controlled trials evaluating the effect of exercise on survival in dialysis patients, the results of a non-randomized study of the association of changes in physical activity with survival in dialysis patients were used to inform sample size calculations [