Fig. 1.

Study design and sampling moments. A: in study 1, the effect of acute exercise [cardiopulmonary exercise test (CPET)] on plasma microRNA (miRNA) levels was studied in 32 chronic kidney disease (CKD) patients and 12 healthy subjects (HS). B: in study 2, the effect of chronic exercise on plasma miRNA levels was studied as part of a single center randomized controlled trial. In total, 40 patients with CKD stages 3 and 4 were involved, and measurements took place at randomization and after 12 wk of aerobic training [exercise training (ET); n = 19] or usual care (UC; n = 21). In a substudy of patients (ET n = 13; UC n = 9), the effect of chronic exercise on the acute exercise-induced response on plasma miRNA was evaluated to unravel mechanisms for adaptation to exercise. PRE, pre-CPET; POST, post-CPET.