Effects of physical exercise during pregnancy and protein malnutrition during pregnancy and lactation on the development and growth of the offspring's femur.

Objective: To evaluate the effects of physical training of mother rats during pregnancy associated with a low-protein diet offered during pregnancy and lactation on the development and growth of the femur of their offspring.

Methods: Forty 90-day old male Wistar rats were divided into four groups: pups of sedentary nourished mothers, pups of sedentary malnourished mothers, pups of trained nourished mothers, and pups of trained malnourished mothers; all groups included 10 rats. Physical training on a treadmill for 8 weeks, 5 weeks before conception and 3 weeks in the gestational period for mother rats of pups of trained nourished mothers and pups of trained malnourished mothers. Induction of low-protein diet to the mother rats during pregnancy and lactation for the groups of pups of sedentary malnourished mothers and trained malnourished mothers. After the pups were sacrificed, on the 90th day of life, we analyzed weight, length, and femoral bone mineral content.

Results: Decreased body weight, femur weight, and femur length (p < 0.05) were observed for the groups of pups of sedentary malnourished mothers and trained malnourished mothers in comparison with to the groups of pups of sedentary nourished mothers and trained nourished mothers, respectively. There was no difference in bone mineral content of the femur in either of the groups.

Conclusion: Mild physical training on the treadmill during pregnancy does not interfere with bone development and growth of the offspring. However, protein malnutrition during this period and during lactation promotes permanent damage to the bone structure of the offspring.