HIGH-INTENSITY EXERCISE DURING PREGNANCY OF RATS - EFFECTS ON MOTHER AND OFFSPRING

We see in this study the effect of high intensity exercise (90% VO2 ma x) in pregnant rats and their offspring depending on the length of pre gnancy. The findings were compared with those obtained for sedentary p regnant rats and non-pregnant rats for similar exercise. This allowed for analysing the isolated effects of exercise (against the sedentary non-pregnant rat control group), of pregnancy and of the interaction b etween the two factors. For checking the effect of the length of pregn ancy, each group of rats was subdivided into those with pregnancy term inated or sacrificed on the seventh, fourteenth or twentieth day of th e experiment. VO2 max, post-exertion blood lactic acid level, body wei ght gain, food intake, feed efficiency, glucose, triglyceride, total c holesterol, total protein and albumin plasmatic concentrations in adul t rats, and weight and number of offspring of pregnant rats were deter mined. Pregnancy increased weight gain and feed efficiency from the fi rst week of the study, accompanied by a greater food intake (from the twelfth day). In the group of pregnant rats subjected to exercise, the re was a reduction in weight gain percentage and feed efficiency in th e first and third weeks, staying the same in the second week. A greate r food intake during the period accompanied this recovery in the secon d week. In the group of non-pregnant rats subjected to exercise, food intake did not vary. As the weight gain percentage was less in relatio n to the non-pregnant control group, feed efficiency decreased. Pregna ncy induced a drop in blood sugar level starting in the second week, a nd the exercise performed during pregnancy did not change this behavio r. Pregnancy produced, however, an increase in plasmatic concentration of triglycerides and total cholesterol during the third week of pregn ancy. Exercise performed by pregnant rats also did not change this beh avior, but the increase observed in the third week was less. Exercise performed by non-pregnant rats did not change the blood sugar level an d plasmatic concentration of triglycerides and total cholesterol durin g the entire experiment. Plasmatic concentration of total proteins and albumin showed a drop in the third week of pregnancy, probably due to high fetal use of proteins in this stage. Exercise performed by the p regnant group caused a lower protein drop in the third week, and in th e non-pregnant group, determined an increase in plasmatic protein conc entrations. The weight of the offspring of mother rats exercised until the end of the second and third weeks of pregnancy was found to be re duced in relation to the sedentary pregnant group. The group exercised until the third week showed a reduction in the number of offspring, i ndicating a possible fetal reabsorption. These findings confirmed that high intensity exercise can produce deleterious effects on the mother and fetus, especially when applied up to the last stage of pregnancy.