Effects of intradialytic exercise on functional capacity in patients with end-stage chronic kidney disease: a systematic review and meta-analysis

The study aimed to investigate the effect of intradialytic exercise training programmes on the submaximal functional capacity of patients with kidney failure. We searched for randomized clinical trials that assessed submaximal functional capacity using the 6-min walk test (6 MWT) in adult patients on maintenance haemodialysis submitted to intradialytic physical training. The search was performed on 15 October 2021, in different databases. Random-effect, multivariate meta-regression adjusted for multiplicity were performed to examine the relationship between exercise effect and covariates. Intradialytic physical exercise induced greater changes in 6MWT distance (k = 18; n = 1,458; WMD: 37.0; 95% CI 29.3; 50.6 metres) than control groups, with substantial heterogeneity (I2 = 78.3%). Aerobic, strength, and combined exercise promoted an average increase of 48.7 (95%CI 30.9; 66.4 metres), 16.9 (95%CI 7.6; 26.3 metres), and 75.8 (95%CI 55.1; 96.6 metres) metres, respectively. Strength training resulted in inferior gains in 6MWT distance compared to aerobic training (WMD: -25.0; 95%CI: -49.1; -0.9). Intervention length shorter than 11 weeks (WMD: 37.0; 95%CI: -5.4; 79.3 metres) did not induce greater changes in 6MWT compared to control groups. There was a positive response in submaximal functional capacity to intradialytic training in kidney failure patients on maintenance haemodialysis.