Preggo Health Nut

Pregnant and fit is not an oxymoron.. its possible!

Pregnancy and Exercise… the Myths

on August 15, 2012

When it comes to pregnancy there are numerous old wives tales out there… especially with exercising and nutrition while preggo. Here are ten myths when it comes to exercising while pregnant, some of the answers are long but great information… so get ready, buckle up and lets bust some myths!

Myth 1– Exercise should never last longer than 15 mins.
Fact– The black and white limit arose in the initial attempt to set conservative and safe guidelines for women who exercised throughout their pregnancies (ACOG 1985). More current guidelines- backed by research that says women with uncomplicated pregnancies can exercise with virtually the same safeguards as nonpregnant women- support that women can exercise for longer periods of time (30 mins or longer, most if not all days of the week) as long as the remain well-hydrated and perceive the exercise as mild to moderate (ACOG 1994,2002) ACOG guidelines even encourage women who did not exercise prior to their pregnancy not only to adopt healthy behavior changes related to nutrition and other lifestyle choices but to also begin a progressive and moderate exercise program (ACOG 2002).

Myth 2– Exercising heart rate should never exceed 140 beats per minute.
Fact– Research has revealed that a blanket recommendation like this was very limiting for women who found a heart rate of 140 beats per a min barely more taxing than a warm-up level of effort. New guidelines tell women they can engage in regular mild to moderate exercise on most, if not all, days of the week (ACOG 2002). This change in wording is significant because it allows each woman to gauge her own fitness level and perceived level of effort, which can better match individual fitness needs.

Myth 3– Exercise causes low birth weight babies.
Fact– Research findings have been inconsistent with regard to fetal weight in women who exercise. Some studies of exercising pregnant women show lower birth weight, no difference, and heavier babies at birth (Artal and Sherman 1999). One review concluded that “current evidence appears the indicate that participation in moderate to vigorous activity throughout pregnancy may enhance birth weight,” although the study cautioned that more severe regimens could result in lighter offspring. According to Pivnark (1998), sufficient calorie quantification is critical to evaluate before definitive conclusions can be made regarding exercise and birth weight- (calorie quantification is what is missing from most studies). James Clapp (1998) found that vigorous and regular exercise throughout pregnancy decreases fetal fat without decreasing overall growth. So basically, women who exercise don’t have low birth weight babies (less than 5lbs 8 oz) but may have lighter and leaner babies.

Myth 4– Vigorous exercise causes miscarriages or premature labor, and pregnant athletes who exercise hard compromise maternal and fetal health.
Fact– A normal rate of miscarriage is between 15 and 20 percent. The incidence of miscarriage for pregnant exercisers and pregnant non-exercisers is 16 to 17 percent (Clapp 1998). Continuing exercise throughout pregnancy does not lead to a higher incidence of miscarriage or birth defects.
As for premature labor, the concern is that increased norepinephrine and prostaglandin output during exercise (or prolonged standing) could stimulate uterine activity and premature labor. One study concluded, “the observed reduction in risk of preterm delivery in a general obstetrical population is evidence of the safety, as well as the potential benefits of exercise during pregnancy: (Artal and Sherman 1999, p. 57).
As far as vigorous exercise, although a moderate exercise regimen is generally recommended during pregnancy, some highly conditioned pregnant athletes appear able to train safely at very demanding levels of exertion. Kardel and Kase (1998) found that an intense exercise protocol that was continued nearly to term had no adverse affect on fetal growth. Moderate to vigorous training appears to have no adverse affect on maternal and fetal health, although this type of training certainly pushes the limits of exercise during pregnancy. More research is needed in the area of vigorous exercise and its impact of fetal growth and core temp during pregnancy (Schnirring 2002).

Myth 5– If you’ve never exercised, don’t start an exercise program during your pregnancy. You’ll do more harm than good.
Fact– This is an outdated line of thought. Pregnancy should not be an excuse to remain sedentary or a reason to gain unnecessary weight (ACOG 2002). Exercise can potentially reduce the likelihood of gestational diabetes (ACOG 2002; Schinirring 2002), especially in obese pregnant women (Artal 1998). Exercise has the potential to reduce insulin resistance and increase insulin action (effectiveness). Once you have approval from your doctor to start an exercise program… go for it! Here are some more benefits; improved postnatal recovery time, appropriate weight gain, and decreased fatigue. Start slowly, listen to your body, and otherwise use common sense with regard to exertion levels and discomfort. Pregnancy and the heightened awareness of self-care and fetal care that naturally comes with it, might be an excellent time to begin an exercise program that can positively affect a mother’s health for a lifetime (Schnirring 2002; ACOG 2002)… this is basically what happened to me, read about it in my about me section!

Myth 6– Running is contraindicated or never advised during pregnancy.
Fact– Recommended exercise regimens should emphasize low-impact activities such as stationary bicycling, swimming, walking, or low impact aerobics. However, running is not off-limits and is very much and self-limiting exercise. You should be in touch with your body enough to be able to honestly discern when running no longer feels good. Generally this occurs during the 3rd trimester as the fetus increases in size. Note that one elite marathon runner continued to train an average of 66.5 miles weekly up to 3 days before birth of healthy twins (Bailey, Davies, and Budgett 1998.) And recently an woman finished the Chicago marathon then proceeded to the hospital to give birth to her baby (check out the article)!

Myth 7– Strength or resistance training is inappropriate during pregnancy.
Fact– Participation in a full range of activities is generally safe (with modifications). Contact sports of those that have a high risk of falling or could cause abdominal trauma (ice hokey, soccer, basketball, and down hill skiing) and scuba diving (puts the baby at higher risk for decompression sickness) should be avoided. As far as resistance training, generally moderate to light loads that maintain muscular fitness while minimizing the potential for ligament for joint injury are encouraged. Heavy loads should be avoided unless appropriately prescribed and simultaneously supervised.

Myth 8– A woman can eat anything she wants during pregnancy, and nutritional supplements are not necessary because so many calories are being consumed.
Fact– Generally, 200 to 300 extra calories should be added to daily intake by the second trimester to help ensure a healthy weight gain of 25 to 35 lbs and adequate caloric intake. Excessive weight gain is not encouraged (ACOG 2002). Protein needs are about 75 to 100 grams per day, calcium 1,000 to 1,200 milligrams, and iron 30 milligrams; the B vitamins become increasingly important because they help to facilitate maternal and fetal energy metabolism (energy need increase greatly during pregnancy). Folic acid (folate) needs double during pregnancy to 800 micrograms per day and can help prevent neural tube defects (ex: spina bifida) or anencephaly (an often fatal condition related to the brain not fully developing) in the fetus. Folate supplementation before and during the first few weeks of pregnancy is critical. Good nutritional habits should start before an anticipated pregnancy and continue for the rest of your life. (check out my post on nutrition while pregnant and caloric intake for more info!)

Myth 9– Exercise will harm your baby.
Fact– Because knowledge in this area is far from complete, concerns remain about the well being of the developing fetus when the mother participates in exercises during pregnancy. Until definitive are available guidelines will continue to err on the conservative side. Ultimately you need to go according to your own common sense and feelings on the matter. Here is a more recent study on pregnancy and exercise; here is another study done on the matter.

Myth 10– Science proves that concerns about exercise during pregnancy have been laid to rest.
Fact– Some areas of research are inconclusive in some of the areas of exercising while pregnant. So ALWAYS consult your doctor first and listen to your body! You know what is too much and what is just right for your physical exertion. There are many benefits to exercising while pregnant and even if you aren’t able to get to the moderate end of the scale.. even little and low resistance training can benefit you! Start at the level you are comfortable with even if it seems like nothing, and then slowly work your way up!

Hope this information helps pretty much ALL of it came from, The Complete Book of Personal Training by Douglas S. Brooks (except for my own personal tid bits here and there). If you have any questions as always… just ask!


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