Effects Of HIIT During Pregnancy On Changes In Cardiopulmonary Parameters And Glucose And Lipid Metabolism Biomarkers - A Randomized Control Trial

PURPOSE: Firstly, we aimed at answering whether the high intensity interval training (HIIT) will positively affect the cardiopulmonary parameters in pregnant women; secondly, will biomarkers of glucose and lipid metabolism remain normal after HIIT intervention? METHODS: It was a randomized control trial in 53 Caucasian women in uncomplicated, singleton pregnancy (age 32 ± 4 years, 22 ± 4 week of gestation; mean ± SD). There were 34 women in the experimental group, who completed 8-week supervised, online high intensity interval training program (HIIT group). There were 19 pregnant women in the comparative (EDU) group who completed educational program. We encouraged them to perform moderate to vigorous physical activity on their own. Before and after the interventions we measured maternal oxygen consumption during a progressive maximal exercise test on a cycloergometer with respiratory gas analyzer. On the days of exercise tests, we assessed selected glucose and lipid metabolism biomarkers from blood samples in fasting condition: glucose, glycated hemoglobin, insulin, lipid profile, irisin and leptin. Both groups presented similar values of analyzed parameters at baseline. RESULTS: The most important finding is that after 8-week intervention the HIIT group substantially improved the maximal minute ventilation (VEmax; p = 0.045) and maximal load (Lmax; p = 0.013). The values of maximal oxygen consumption (VO2max), oxygen consumption at anaerobic threshold (VO2/AT) and maximal heart rate (HRmax) remained at the same levels (respectively: p = 0.732; p = 0.828; p = 0.844), despite the pregnancy progression and physiological weight gain. In comparison to the EDU group, the HIIT group presented substantially better levels of all abovementioned cardiopulmonary parameters: VEmax (p = 0.003), Lmax (p = 0.006), VO2max (p = 0.001); VO2/AT, (p < 0.001); HRmax (p < 0.001). Both interventions were effective to keep the levels of glucose and lipid biomarkers within the normal range for pregnancy. We have not observed any adverse obstetric and neonatal outcomes in either group. CONCLUSIONS: Both supervised HIIT and self-performed moderate to vigorous physical activity can be recommended for prevention of metabolic disorders during pregnancy. However, to improve exercise capacity, women should be subjected to HIIT programs.