Ejercicio En El Embarazo

SUMMARY
The role of exercise in pregnancy (EIP) is widely debated. Pregnancy produces marked changes of several physiologic variables of the mother. Regular EIP limits the increase in O2 requirement and produces an increase in the absolute anaerobic threshold, which persists for up to 36 weeks. Exercise in pregnancy reduces the incidence of muscle cramps, lower limb edema, fatigue, andshortness of breath. Increased knee cruciate ligament laxity does not normally produce any instability. Exercise in pregnancy reduces the increase in baseline maternal heart rate that occurs in pregnancy. Heart rate and stroke volume increase more markedly with exercise in pregnant women than in nonpregnant controls. Noradrenalin response to EIP is lower than in nonpregnant controls. Blood glucose levelsdecrease more promptly and to lower values with exercise in pregnant women than in nonpregnant controls. Glucose tolerance normally decreases in pregnancy, but increases during EIP. Regular EIP improves glucose tolerance in diabetic mothers and reduces total maternal weight gain and subcutaneous fat deposition toward the lower end of the normal range. Regular EIP produces higher plasma endorphinlevels during labor and better pain tolerance than in sedentary controls. Women who undertake regular EIP have a lower incidence of 3rd- and 4th-degree vaginal tears. Children of exercising mothers have similar birth-weights as children of sedentary mothers, and mental performance at age 5 is higher. If there are no specific obstetric or medical contraindications, fit pregnant women can safelymaintain the same level offitness during pregnancy, although exercise schedules may have to be reduced. Key Words: Pregnancy, Exercise, Weight gain, Adverse effects, Beneficial effects.

INTRODUCTION
Increasing numbers of women engage in sport to keep fit, often in the reproductive years. The decision to stop or curtail a program of regular exercise when a pregnancy is diagnosed should thereforebe based on objective and reliable information. Often, women may be advised by friends or by their doctors to turn to a more sedentary lifestyle when pregnant, on the assumption that exercise may increase the risk of miscarriage or cause harm to the developing fetus. On other occasions, women themselves may make this decision. Not all sports have the same impact on pregnancy, and intensity andduration of exercise sessions should be taken into account. Leisure exercise, such as moderate walking or biking or swimming, generally involves aerobic work and causes limited increases in maternal heart rate and ventilator frequency. On the other hand, competitive sport may involve frequent maximal or near-maximal performances when the aerobic–anaerobic threshold may be reached. Maternal level oftraining and general fitness, particularly respiratory and cardiovascular reserves, set the safe level of exercise affordable by a pregnant woman.

In at-risk pregnancies, discontinuation of exercise may be necessary, and it is important that such cases are managed by expert medical personnel. In the absence of maternal cardiovascular or respiratory problems, moderate exercise makes the motherenjoy a sense of well being, is often associated with a shorter labor and a lower incidence of operative deliveries, and may help in the management of conditions such as diabetes and hypertension. The influence of regular maternal exercise on fetal development is controversial, because diversion of blood from the placenta to maternal muscles and other organs involved in the exercise is deemed bysome authors to interfere with normal fetal growth. At present, a significant difference in birth weight between babies born to exercising mothers and sedentary controls has not been confirmed. Other studies evaluating mental and physical development of children born to exercising mothers also show encouraging data.

Finally, an important issue for its impact on pregnancy outcome is maternal...