Your preconception fitness level indicates the level of physical activity you can continue into a healthy pregnancy. Likewise, the level of activity you’re able to maintain up until your third trimester is directly related to the intensity, duration and type of exercise you can perform until you deliver. Certain activities, such as yoga and running, require modification in the third trimester. In addition, common late pregnancy symptoms might demand that you slow down, but gentle exercise is still possible in most cases. Discuss your prenatal workout program with your obstetrician or midwife throughout your pregnancy, especially if you experience exercise-related discomfort.
Beginning with the 28th week of pregnancy, a woman enters her third and final trimester. Late pregnancy is commonly marked by steady weight gain, shortness of breath, renewed fatigue and an increasing anticipation of childbirth. Some women also experience general discomfort that can lead to restlessness and difficulty sleeping. The increasing weight of the uterus puts pressure on pelvic floor muscles, which can result in bladder leakage while coughing, sneezing or laughing. The uterus can also put pressure on the sciatic nerve, causing sciatica, a shooting pain that runs from the buttock down the back of the thigh. Calf cramps and pelvic pain are two other typical symptoms of late pregnancy.
Late Pregnancy Exercise
Until the baby drops during the last few weeks of pregnancy in preparation for birth, the upward pressure of your uterus on your diaphragm can make you feel as if you’re always short of breath. Performing aerobic exercise at a moderate intensity throughout pregnancy improves breathing and boosts circulation. Health care providers typically recommend walking, stationary cycling and swimming to their pregnant patients because the workouts are low- to no-impact and easy on the joints. Swimming, water aerobics or jogging in the pool are especially beneficial in the third trimester. As your center of gravity continues to shift and your body gets heavier, the water can alleviate related discomfort by giving you buoyancy.
Rate of Perceived Exertion
In the past, pregnant women of every fitness level and in every trimester were told to gauge the intensity of their aerobic workouts by heart rate, and not to exceed 140 beats per minute. Recommendations in 2011 guide you to use Borg’s rate of perceived exertion, or RPE, chart to monitor and adjust your intensity. The scale runs from 6 to 20, or a corresponding “no exertion” to “maximal exertion.” If your physician hasn’t given you any exercise restrictions, aim to keep your effort between 12 and 15, or “very light,” to “somewhat hard." RPE compensates for your body’s condition; what feels very light to you in your first trimester may feel somewhat hard in your third.
Certain exercises that are beneficial throughout pregnancy are especially beneficial in the last trimester as labor and delivery draw near. Kegel exercises, which strengthen and tone the pelvic floor muscles that support your bladder, bowels and uterus, are safe and important for every pregnant woman, even those assigned to bed rest. Strong pelvic floor muscles aid in positioning your baby’s head during delivery and can help you minimize your risk of late pregnancy -- and postpartum -- hemorrhoids or urinary incontinence. Pelvic tilts, hip circles on the exercise ball, wall-supported squats and lower back stretches are all helpful during your last trimester.
- Healthy Moms Perinatal Fitness Instructor Training Manual; Sheila Watkins
- ACSM.org: Exercise During Pregnancy