Patients with CKD stages 3b to 4 were randomly assigned to the exercise ( n = 20 ; 11 men ; median age , 63 [ IQR , 57-65 ] years ; median estimated glomerular filtration rate , 28.5 [ IQR , 19.0-32 .0 ] mL/min/1 .73 m ( 2 ) ) or nonexercise control ( n = 18 ; 14 men ; median age , 66 [ IQR , 45-79 ] years ; estimated glomerular filtration rate , 20.5 [ IQR , 16.0-26 .0 ] mL/min/1 .73 m ( 2 ) ) group .