Impact of different exercise intensities on pregnant rats and on their offspring.

Aline O Netto,Franciane Q Gallego,Nathália C Dias Macedo,Débora C Damasceno,Elena Zambrano,Yuri K Sinzato,Gustavo T Volpato

doi:10.1590/0001-3765202020191572

Abstract

This study aimed at evaluating the levels of different maternal exercise intensities on maternal and fetal outcomes. Wistar rats were mated and the pregnant rats were distributed into four experimental groups (n = 13 animals/group): Control (Not exercise group - 0% of the anaerobic threshold- AT), mild (20%), moderate (80%), and heavy-exercise intensity (140% of AT). These AT were matched to the load of 0, 1, 4 and 7% of the body weight of the animal related to swimming-induced physical intensity. In pregnancy, biomarkers related to maternal blood gases, oxidative stress, metabolism, and reproductive performance, and outcomes of their offspring were analyzed. The mild and moderate-swimming caused no change on implantation, live fetus numbers and oxidative stress status. However, the rats submitted to mild-exercise presented respiratory alkalosis and the heavy-exercise group showed respiratory acidosis. In addition, fetuses of the heavy-exercise dams were smaller for gestational age and lower serum adiponectin levels compared to those of other groups. In conclusion, the moderate-exercise intensity caused beneficial effects for maternal environment and the mild and moderate-exercise presented similar fetal repercussions. Nevertheless, the heavy-exercise intensity caused maternal metabolic alterations that damaged the fetal growth. Therefore, these findings confirm that physical intensity should be carefully conducted to avoid maternal complications and, consequently, compromised fetal repercussions.

Highlights

Water immersion is one of the best resources to increase the aerobic capacity of pregnant women (Juhl et al 2010)
Mild and moderate-exercise groups had at term pregnancy, were able to swim the complete program, and presented no death in these groups, except one rat submitted to moderate swimming program that bled before swimming and was removed from the group
The heavy-exercise group began the experiment with 13 animals, and three of them died during the experiment, totalizing 10 rats at term

Summary

Introduction

Water immersion is one of the best resources to increase the aerobic capacity of pregnant women (Juhl et al 2010). Considering the most recent ACOG guidelines (2015), all pregnant women, without obstetric and medical contraindications, should be encouraged to exercise in a manner similar to the guidelines that are given to non-pregnant women. They can practice aerobic and strength exercises with moderate intensity for at least 20 to 30 minutes a day on most days of the week (Perales et al 2017). Several biochemical markers of physical training provoked great interest and represent a significant advance in recent decades for a better understanding of the importance of physical exercise practice for the health of the population. Enzymatic activity of citrate synthase is studied, as it is relevant for the evaluation of oxidative

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