Journal of Applied Physiology, Vol 60, Issue 5 1700-1703, Copyright © 1986 by American Physiological Society
Influence of exercise training on maternal and fetal morphological characteristics in the rat
J. Treadway, E. V. Dover, W. Morse, L. Newcomer and B. W. Craig
Evidence in both humans and animals has shown that exercise before or
during pregnancy may effect fetal outcome. The purpose of this
investigation was to examine the effects of an exercise program on fetal
development in the rat. Prior to impregnation one group of animals was
exercise-trained on a Quinton shock-stimulus rodent treadmill. The
exercised group was trained to run 5 days/wk, for 2.0 h/day at 31 m/min up
an 8 degree incline for 8 wk before mating. Following mating the training
intensity was reduced to 27 m/min up a 5 degree incline, and the exercise
period decreased to 1 h/day. On day 19 of gestation, 24 h postexercise for
the trained mothers, the animals were killed in the fed state and the
maternal and fetal characteristics were measured. The sedentary controls
gained significantly (P less than 0.05) more body weight during pregnancy.
This can be attributed to three factors: higher number of fetuses, 14.83
+/- 0.04 vs. 12.2 +/- 0.85 for the trained; larger litter weights, 44.25
+/- 4.97 vs. 26.17 +/- 1.82 g/dam for the trained; and slightly larger
lipid stores. In addition to having fewer pups the trained mothers had a
greater number of fetal resorptions; 0.9/dam as opposed to 0.17/dam for the
sedentary control. Analysis of fetal body composition showed no difference
in total body water, protein, or fat between the pups of sedentary and
trained dams. The results of this study indicate that exercise training
prior to and during pregnancy influences fetal development in the rat.
