One of the age-old concerns of exercise in pregnancy is that blood flow to the foetus is decreased. During exercise your blood flow to the uterus decreases so that oxygenated blood can be delivered to the exercising muscles.
HOWEVER, your body will do anything in order to protect your growing baby and adapts to supply not only oxygenated blood, but richly oxygenated blood to your baby when you exercise.
From early in your pregnancy, the hormone progesterone is released and stimulates breathing. You may have noticed that you feel short of breath even if you have not done anything particularly strenuous. By breathing faster, you are increasing the amount of oxygen that you are taking in to your body and in fact your lungs function 40 – 50 % better compared to when you are not pregnant. Research has also shown that the combination of training and pregnancy improves your lungs’ ability for aerobic work by 5 to 10%!
Studies have shown that the placentas of women who exercised regularly in early to mid pregnancy grew faster and functioned better than those of healthy non-exercising women. (This means good nourishment for baby all the time)
In pregnancy (as in elite athletes ) you become anaemic – not because you don’t have enough iron in your body, but because there is more fluid than normal in your blood. This is called dilutional anaemia. Anatural consequence of exercise is that you lose fluid due to sweating, breathing faster and increased metabolism. This in turn results in your blood becoming more concentrated and the proportion of red blood cells corrects. This is the blood that gets delivered to your baby when you train – full of oxygen-rich haemoglobin!
Advantages to the growth and development babies of exercising moms have been found both in-utero and even up to the age of 5 years. Babies of exercising moms are less vulnerable to the usual physiological stresses of later pregnancy and labour. They have an improved ability to deal with intermittent reductions in uterine blood flow and oxygen delivery. This provides additional protection when unanticipated maternal stresses occur, for example: serious traumatic injury, other medical emergencies and complications during labour. There is a lower incidence of umbilical cord entanglement.
Due to this ability of handling physiological stresses, there is also a lower incidence of stress-induced meconium secretion during labour.
Once born, babies born to exercising moms tend to be leaner than those born to non exercising mothers. They respond more readily to things in their environment. They can readily self-quiet when they are disturbed and need much less consolation from others. All aspects of growth and development after birth in babies from exercising mothers are equal to or better than those observed in the non exercising mothers’ offspring. At one year of age, significantly better performance on standardized intelligence tests (Bayley Test of Infant Development) both in mental and physical performance.
Finally, at five years of age, they tend to have less body fat than others in the control group!
Source: Dr Etti Barsky (MBBCh, MSC Sports Science), the training director of Preggi Bellies South Africa