Kenneth Gardner
THE HEALTH benefits of exercise and the increasing participation by women in exercise have raised concerns about the role of exercise for the mother and foetus during pregnancy.
Exercise during pregnancy represents a unique situation because of the possible competition between exercising maternal muscle and the foetus for blood flow, oxygen delivery, glucose availability and heat dissipation. Metabolic and cardio-respiratory adaptations to pregnancy may alter the response to acute exercise and the adaptation that results from physical exercise.
It is believed that exercise during pregnancy may develop increased capacities for supporting the foetus, such as improved cardiovascular function and carbohydrate metabolism. Based on the analysis of the effects of exercise during pregnancy on the mother and foetus, there is no evidence to indicate that exercise performed three times per week for up to 45 minutes at a heart rate of 144 beats per minute is harmful.
FREQUENCY AND INTENSITY
The American College of Gynaecology recommends a similar frequency and intensity, but with a duration of no more than 15 minutes. Exercise performed for longer durations at higher intensities or during hot, humid conditions (increased thermal stress) may be unsafe.
Due to the decrease in the potential for trauma, non-weight- bearing exercise such as cycling, swimming or other aquatic-based activity is recommended during pregnancy. As a result of the importance of exercise intensity and duration to the specific benefits and dangers to the mother and foetus, it is important to recognise that what may be good for the mother may be detrimental to the foetus. The risk may be in the impairment of foetal well-being and this is a primary concern when exercising during pregnancy.
The benefits of a well developed perinatal exercise prescription include improved aerobic and muscular fitness, facilitation of recovery from labour, enhanced maternal psychological well-being. Women who are appropriately screened prior to initiating exercise and who are educated regarding signs and symptoms for discontinuing exercise, typically do not experience problems while exercising. Exercise with a physician's authorisation can contribute to better maternal health and offer minimal risk to the developing foetus.
Women who begin an exercise programme after becoming pregnant are advised to receive physician authorisation and begin exercising with low- intensity or non-impact activities such as walking and swimming. Women who exercise regularly return to their pre-pregnancy weight, strength and flexibility levels faster than their sedentary counterparts.
Recommendations for exercising during pregnancy and post-partum.
Mild to moderate exercise routine at least three times per week is preferable to intermittent activity.
Avoid exercise in the supine position after the first trimester.
Prolonged periods of motionless standing should be avoided.
Modify the intensity of the exercise according to maternal symptoms.
Stop exercising when fatigued and do not exercise to exhaustion. Weight-bearing exercises may under some circumstances be continued at intensities similar to those prior to pregnancy throughout pregnancy.
Non-weight-bearing exercises such as cycling or swimming will minimise the risk of injury and facilitate the continuation of exercise during pregnancy.
Exercises involving the potential for even mild abdominal trauma should be avoided.
Those who exercise in the first trimester should augment heat dissipation by ensuring adequate hydration and appropriate clothing.
Pre-pregnancy exercise routines should be resumed gradually based upon a woman's physical capability.
DISCONTINUE EXERCISE IF:
Sudden swelling of the ankles, hand or face occurs, and seek medical advice.
Persistent severe headaches and/or visual disturbance, unexplained spell of faintness or dizziness occur.
Swelling, pain, redness in the calf of one leg (phlebitis) occur.
Elevation of pulse rate or blood pressure persists after exercise.
Excessive fatigue, palpitations, chest pain, unexplained abdominal pain, insufficient weight gain occur.
Kenneth Gardner is an exercise physiologist at the G.C. Foster College of Physical Education; email: yourhealth@gleanerjm.com.
