The acute effect of maximal exercise test and chronic impact of an 8-week HIIT program on albuminuria and kidney function in the 2nd and 3rd trimester of physiological pregnancy. 

Objectives: Physical activity is an important part of healthy lifestyle and should be continued during uncomplicated pregnancy. Several studies have suggested that most of the pregnant women had no contraindications to perform exercises. The aim of the study was to assess the acute effect of maximal exercise test and chronic impact of an 8-week HIIT program on albuminuria and kidney function in the 2 nd and 3 rd trimester of pregnancy. Methods. A group of 36 pregnant women was studied. At the beginning of the study, all participants had normal kidney function and albuminuria at rest. Nineteen women participated in an 8-week HIIT program and seventeen in an educational program (EDU group). Before and after the training or education programs, a progressive maximal exercise test on cycloergometer was conducted. Several biochemical measurements were performed to assess changes in kidney function. Results. After short exercise test, some unexpected findings were observed: the fractional excretion of urea and uric acid increased (FeUrea from 41.25 to 50.05%; FeUA from 7.18 to 8.04%) and serum uric acid decreased significantly (sUA from 3.35 to 3.28mg/dL). The HIIT program had no impact on kidney function at rest. In both groups, significant increases in eGFR and sUA were observed. An interesting observation was that uACR increased significantly only in EDU group. Conclusion. Changes in kidney function after short intensive exercise in pregnancy were typical for healthy subjects, but there was no negative impact on markers of renal hypoperfusion. The supervised HIIT program had no negative impact on kidney function.