9 Myths You May Still Believe About Pregnancy Exercise That Could Harm You and Your Baby - Total Mommy Fitness™
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9 Myths You May Still Believe About Pregnancy Exercise That Could Harm You and Your Baby

Staying physically active during pregnancy relieves stress, improves mood and sleep, boosts confidence and increases body awareness. Research has indicated that women who exercise throughout their pregnancy tend to have shorter, less difficult labors with fewer complications. They also have a decreased need for medical intervention with quicker, easier recoveries once the baby is born. Other benefits include better posture, decreased back pain, less swelling and constipation, as well as a reduced risk for gestational diabetes, preeclampsia, and other pregnancy related ailments.

Research has shown that physically active pregnant women even tend to have healthier, smarter babies!

pregnancy exerciseA study released by the American Academy of Physical Medicine and Rehabilitation concluded, “There is a direct link between healthy mothers and healthy infants. Exercise and appropriate nutrition are important contributors to maternal physical and psychological health,” (1). Another recent study explained, “While early studies on the effects of physical activity during pregnancy were concerned about possible harm to the mother or fetus, these fears have not been substantiated. Instead, a growing body of literature has documented several health benefits related to pregnancy physical activity.” (2)

Fascinating science has also shown that an unborn child benefits from the struggle for nutrients when a mother is increasing her oxygen intake and blood flow during physical activity. Researchers said, “As the site of nutrient transfer, the placenta is pivotal in the tug-of-war between mother and fetus over resource allocation. It responds to both fetal signals of nutrient demand and maternal signals of nutrient availability and adapts to regulate the distribution of available resources. These adaptations involve changes in placental size, morphology, transport characteristics, metabolism, and hormone bioavailability…,” (3). In other words, just like a muscle is made stronger through the workload of strength training, a woman’s placenta and fetus are made stronger by exercise. The increased demand for nutrients, blood flow, and oxygen that exercise creates is like its own little workout for baby!

Staying active after giving birth has many benefits, too, including better sleep, increased energy, improved mood, and faster recovery. A randomized controlled trial study evaluating the effects of rehabilitation exercise on the well-being of new moms found that “Exercise and health education programs are effective in improving postnatal well-being. Consistent use of the program may reduce longer-term problems such as postpartum depression,” (4). Yet, even with all of these proven benefits, there are still many myths and misinformation circulating about the “dangers” of staying active during pregnancy. Please, do not believe them!

Myth #1 “Exercise will overheat the baby.”

Reality: A healthy woman can exercise without overheating, though it is best to wear loose-fitting clothing and stay hydrated to allow the body to stay cool. It is also wise to avoid hot baths or saunas, which raise the body’s core temperature. There is some risk to the fetus from overheating during pregnancy. However, just because the mother is feeling hot, that does not mean the baby is at risk. There is an increase in thermoregulation that occurs during pregnancy, which allows excess heat to be pulled away from the fetus as a protection.

Myth #2 “Exercise will tangle the umbilical cord.”

Reality: This myth started before it was ever researched, and the science has shown no evidence that exercise increases the risk of a tangled umbilical cord.

Myth #3 “The heart rate can’t rise above 140 beats per minute.”

Reality: When the American Congress of Obstetricians and Gynecologists (ACOG) released recommendations in the 1980’s there had been little research done on prenatal fitness. Once more research was conducted, observing humans instead of rodents, ACOG revised their heart rate (HR) recommendation in the mid-90’s to the rate of perceived exertion (RPE) scale. Since HR naturally increases and fluctuates during pregnancy, relying on HR as a measurement of exertion is ineffective. Women are encouraged to listen to their bodies’ and avoid getting too high on the RPE scale. For example, on a scale of 1-10 (“1” being easy and “10” being exhausting), it is safe to exercise at a 6-7 but may become dangerous if sustained at a 9-10. As long as the expectant mother can talk without becoming breathless or faint her HR, is likely in a safe zone.

Myth #4 “Working out will cause a miscarriage.”

Reality: There is no evidence suggesting that exercise leads to miscarriage, while there are many proven benefits. The first trimester of pregnancy has a higher risk of miscarriage, in general, which is unrelated to exercise.

Myth #5 “Don’t lift more than 25lbs.”

Reality: This is a conservative recommendation commonly given to pregnant women. However, there is a drastic difference in pressing 25lb dumbbells overhead compared to pushing 25lbs on a leg press machine. Therefore, this recommendation is too vague. Listen to your body, use proper form, and stay within a 6-7 on the RPE scale to determine how much to lift.

Myth #6 “Avoid exercises like squats and lunges because of the increased pressure on the pelvic floor.”

Reality: If squats and lunges feel comfortable, and there are no other contraindications, they are safe for pregnancy. They are effective exercises to burn calories, strengthen lower body and core muscles, improve balance, and prepare for labor. As a precaution, it may be wise to squat with a sturdy chair placed behind the hips to prevent falling.

Myth #7 “Do not do pushups, plank or other core exercises because of the strain on the abdominals which can cause them to separate.”

Reality: Abdominal exercises are safe when performed correctly. Diastasis recti (separation of the abdominals) is common in pregnancy from weakening and overstretching of the abs. Many women mistakenly avoid core exercises as a precaution while pregnant. However, abstaining from abdominal exercises will not prevent diastasis recti. In fact, performing safe, modified core exercises, such as the plank and pushup, will decrease the risk of diastasis recti by keeping the core strong and intact.

Myth #8 “Pregnant women should not lie on their back.”

Reality: After the first trimester, lying flat on a hard surface for an extended period can cause symptoms like dizziness, nausea, shortness of breath, increased pulse and decreased blood pressure. This is because of pressure on an enlarged vein called the vena cava, which returns blood to the heart. Simply sitting up or rolling onto the left side can ease symptoms. Lying slightly inclined or on a stability ball are also comfortable alternatives.

Myth #9 “Prenatal Exercise will cause low birth weight.”

Reality: Exercise will not only make mothers leaner and healthier, but it will also make babies leaner and healthier! This means that babies born to exercising mothers will often have less body fat. This is not something to worry about. In fact, there are lasting benefits for the baby, and it can also mean fewer complications during labor. This could even mean that the child will be MUCH less likely to struggle with their weight for decades and generations to come.

Each statement is based on current, credible scientific studies. If you have any questions or concerns, please comment below.

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1) Benefits of exercise during pregnancy.

2) Health benefits of physical activity during pregnancy: an international perspective.

3) Maternal-fetal resource allocation: co-operation and conflict.

4) Obesity, pregnancy, inflammation, and vascular function.

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