Working Out While Pregnant - Should You Lift Weights?

I am sure you have seen some ladies on YouTube that are like nine months pregnant doing heavy squats or snatches and wonder, “Is that good for your baby?” You might even think it is a form of child abuse, as it can bring about pre-term labor and cause problems for the unborn fetus, right?

Lifting weights while pregnant is a pretty controversial subject. To tell you the truth, when I see some lady on YouTube lifting heavy weights overhead while being 9 months pregnant, I cringe inside.

Related - Will Lifting Weights Make You Look Like a Man?

But why? Maybe she’s been lifting weights all her adult life, and why should she stop if she’s pregnant?

When I was pregnant, you just didn’t lift. Like, anything. It was a time of no exercise, eat for two and sit with your feet up so you wouldn’t get ankle swelling; however, things have changed.

Pregnancy isn’t a disability. In fact, you can be quite healthy during your pregnancy if you do it up right.

First, we need to talk about the stages of pregnancy and how lifting can affect these stages. Then we will talk about some of the contraindications of lifting while pregnant. Lastly, we will discuss pros and cons of different exercises while pregnant and how it can affect the unborn fetus.

So let's get into it, shall we?

OK, I guess I don’t need to tell you what happens when the egg meets the sperm, right? Cool, I think you got that one down.

Working Out While Pregnant

First Trimester (week 0 to 13)

So now that the egg and the sperm have introduced themselves and are now co-mingling their chromosomes 23 from the sperm, 23 from the ovum into a nice round number of 46. Ahh, fertilization has commenced.

The pre-embryonic period is what I like to call the honeymoon phase - this is the period of the first two weeks after conception and the cells are dividing like mad. The zygote (that fertilized egg thingy) now decides to move down into the uterus, which takes about 8-10 days to implant.

The zygote is smart, and secretes hCG to signal the woman’s body that, hey, we are pregnant, I have landed - look at me, look at me. HCG causes continuous secretion of estrogen and progesterone until the placenta takes over that job.

The best place that the zygote can land in the upper uterus, because of its rich blood supply, the lining is thicker there than lower in the uterus, and it limits blood loss after birth because (I have to quote, because I know I won't get this right...) “strong interlacing muscle fibers in this area compress open endometrial vessels after the placenta detaches.” (Foundations of Maternal-Newborn Nursing, Saunders 4th Ed).

During the embryonic period (3-8th week of pregnancy) basic structures start to form, like upper and lower limb buds, ears, eye, umbilical cord. It's kinda the first trimester, but after week eight, it is known as the fetal period. The first semester is from 0-13 weeks.

There is an overlap of the embryonic period and the fetal period.

Women don’t usually know they are pregnant until about 6-8 weeks. By that time, the little sucker has implanted, rapidly divided cell wise, and is being formed inside the uterus.

In fact, by week eight, the embryo has definite human form and refinements of all systems (respiratory, circulatory and the like) are continuing. By the end of the 12th week, the fetal gender can be determined by the appearance of the external genitalia.

Second Trimester (week 14-26 weeks)

There is exponential growth during this time - seriously. The head grows smaller in proportion to the total length, fetal movements start at week 17 to 20 and the lungs start to produce surfactant at weeks 21-24.

Surfactant is the stuff that reduces surface tension and helps prevent the alveoli from collapsing upon breathing. The fetus can survive after 21 weeks of pregnancy outside the uterus, however, this may come with many different complications such as lung problems and brain development issues.

The fetus is likely to live without any complications if delivered week 25-28 and beyond.

Third Trimester (27-40 ish weeks)

The fetus is becoming plumper, more subcutaneous fat is depositing under the skin, toenails are present, and pulmonary and circulatory systems continue to mature. Basically, they are incubating in the womb and growing until they get out of that cramped space.

So now you know how the kid is developing, let's talk about what is going on with the carrier - the host, if you will.

So you moms know how emotional you are during pregnancy... My hubby used to think I was just crazy, but there is a lot going on that we need to talk about.

Can anyone say hormones?

I promise that this will relate to weightlifting, but it's important to get what is going on so we can talk nice and educated-like when we get there.

Hormones and Pregnancy

OMG. This is the worst part of pregnancy - never mind being huge and not being able to get up off the floor or the horrible heartburn... The hormones are the worst.

Aldosterone and Cortisol - These hormones are secreted by the adrenals and are increased in pregnancy to conserve sodium and maintain fluid balance. Cortisol also aids in the metabolism of glucose, fats and protein and has an aThat'snflammatory effect so that you don’t reject your pregnancy. Thats kinda important...

Estrogen - Secreted by the ovary and placenta. It stimulates uterine development and provides a nice blood, happy environment for the fetus. It also stimulates the breasts to prepare for lactation.

Follicle-Stimulating Hormone - Secreted by the anterior pituitary. It initiates the maturation of the ovum, but is suppressed during pregnancy.

Human Chorionic Gonadotropin (hCG) - Secreted by the little zygote at first - it maintains the production of progesterone until the placenta is formed.

Luteinizing Hormone - Secreted by the anterior pituitary—This stimulates ovulation of a mature ovum in a non-pregnant state. I just threw this one in to see if you’re paying attention.

Oxytocin - Secreted by the posterior pituitary. This stimulates contractions to initiate labor as well as stimulates the milk ejection reflex after birth.

Prolactin - Secreted by the anterior pituitary. This is the primary hormone of milk production

Progesterone - Secreted by the ovary and placenta. It maintains the uterine lining for implantation and relaxes smooth muscle, including the uterus. It increases the resistance to insulin and also develops the acini cells in the lobes of the breast for lactation.

Relaxin - Secreted by the ovary and placenta - softens the muscles and joints of the pelvis.

Thyroxine - Secreted by the thyroid. Increases during pregnancy to stimulate basal metabolic rate.

Wheeeewwww. Those are a lot of hormones. So let's see how this even relates to lifting weights and females and stuff.

Finally, after all that gobbly-gook we can now delve into what this article is all about. You will see why I wrote about the above, though, when we are talking weightlifting and this pregnancy stuff.

Lifting Weights in the First Trimester

First of all, let me make a blanket statement with this whole lifting and pregnancy bit. You absolutely need to talk to your obstetrician about lifting weights in your pregnancy.

Each person is different and there may be a reason why your physician may not want you to lift weights or there may be a reason he wants you to lift weights. Either way, it is a must to talk to your doctor and get their expert advice.

Ok, good, now let's move on.

The first trimester is very fragile for the zygote. They are trying to implant, there is hCG being released, which causes the baby zygote to persist and continue secretion of estrogen and progesterone until the placenta takes over that job.

Oh, and they have to find a prime real estate spot on which to land - hopefully, they go north on the uterus...

If you have never lifted weights before, it doesn’t mean you can’t start; however, nothing heavy. Being so new and fragile, the zygote might not make a great landing spot to dig in for the next 9 months.

Also, a concern throughout pregnancy is the Valsalva maneuver. It’s that thing you do when you bear down, sometimes you do it when you lift heavy, or poop. This can increase blood pressure and intra-abdominal pressure.

If you are not new to lifting weights, it would most likely not impact you and your little zygote because your body is used to doing this. However, the same applies to you about the Valsalva maneuver; it still increases blood pressure and intraabdominal pressure, so cool it on that.

The positive effects of exercise on the first trimester are better peristalsis (which means better movements of your bowels) as well as improved muscle tone.

At this point, I will tell you that you need to speak with your physician to see how much weight is appropriate to start with.

If you are already squatting 140 pounds, he may have you cut back a bit, but if you are starting out brand new to weight lifting, your physician will likely have you start out with light weight and more reps.

Lifting Weights in the Second Trimester and Beyond

I lump both the second and third trimester together because most likely the fetus has found a great spot to get nutrients, and now is growing, moving and growing again.

Lifting weights can be tricky the farther in pregnancy you go. Squatting for instance or lunging may not be very stable for the woman who is in her mid second trimester and on.

Relaxin, the hormone that relaxes the pelvis to get ready for a bowling ball head to go through the birth canal causes loosening and widening of the pelvis which can cause instability and pain at the symphysis pubis and inner thigh area.

Center of gravity is also changed as the fetus grows. This can throw off balance and may lead to increased back pain due to overcorrection when doing certain exercises and a higher risk of falling.

Also, let's talk boobs. They get in the way because they are growing exponentially in order to be ready for breastfeeding. That damn progesterone!

Talk about annoying. If you are doing anything at all with your arms or even squatting, you will find not only is your center of gravity off, your pelvis is all over the place, but now your boobs are in the way, too.

Exercises that put you flat on your back should be avoided. This can cause decreased cardiac output and hypotension because the fetus is putting pressure on the abdominal aorta.

So, you can’t lay on your back and bench, your pelvis may be all over the place when you squat and your center of gravity is off so it could make you more prone to falls. That about sums it up.

Contraindications to Lifting

Some contraindications for lifting would be the following:

• Previous spontaneous abortion (miscarriage).
• Incompetent cervix/post cerclage (which is a stitching of the cervix to keep the baby in).
• High blood pressure or toxemia/preeclampsia.
• Hyperemesis Gravidarum-severe vomiting throughout pregnancy which can cause electrolyte imbalances, weight loss, and dehydration.
• Bleeding during pregnancy for any reason. This could indicate Placenta Previa, which is when the placenta is implanted low in the uterus or even covers the cervix, or Abruptio Placentae which is when the placenta separates from the uterus.
• Any pain anywhere. Let's assume you are not having any of the above contraindications and you just want to lift. Yes, you're pregnant, but really, you just want to be healthy during pregnancy, not gain a ton of weight and feel good.

What Exercises Should You Do?

OK, you know what I am going to say. Consult your doctor first. Seriously, don’t read one article on lifting and pregnancy and go do it. Your doctor may have very valid reasons why you shouldn’t lift. You absolutely positively need to consult your physician first.

Now that's out of the way, what exercises are the best for a pregnant woman?

Every book out there nursing and otherwise will tell you that the best exercise for a newly pregnant woman all the way up to delivery is walking. Walking 30 minutes a day after you eat is going to decrease heartburn, decrease varicose veins and lessen back pain that you will experience later on during pregnancy.

As for lifting, I found scarce info on it; well besides the pic that went viral of a cross fitter who was lifting 75 pounds overhead and was 38 weeks pregnant. It became very controversial as some felt that she was doing damage to her unborn child.

With this scenario, this woman was skilled in lifting. She was lifting less than she normally would and had built up her strength throughout the years that she had been doing it.

However, if you are starting a strength program when you find out you're pregnant or are not used to lifting weights - this is not the time to lift heavy.

Back to information that I found on lifting weights...

I found a study that the University of Georgia put on that a supervised, low-to-moderate intensity program is safe and beneficial for a pregnant woman.

The Journal of Physical Activity and Health measured progression in the amount of weight used, changes in resting blood pressure and potential adverse side effects in 32 pregnant women over a 12 week period. There were 618 exercise sessions and none of the women experienced a musculoskeletal injury.

In this study, it found there were no differences in blood pressure with weight training versus no weight training.

The women lifted weights, although it does not say what exercises they did and that breathing techniques and learning to lift properly decreased any dizziness that participants experienced in the beginning.

There is information out there that is conflicting—it’s ok to raise your heart rate above 140, no it’s not, it's ok to squat light, or no, it’s not.

My best advice as a trainer and as a nurse?

If you have been lifting prior to pregnancy

Start with light weight and higher reps. Do I think you should do squats? Yes, I do, but again, lightweight. For God sakes, most women have more than one child and she is carrying that kid on her hip when she is pregnant with the second one and we are all scared she might pick up a 5-pound dumbbell?

Really?

If you have been lifting weights, been doing cross-fit or been bodybuilding - continue with your regime with the exception of heavy weight. The farther along you are, don’t bench flat - do incline benching instead so as not to put any pressure on your abdominal aorta and restrict blood flow.

If you are squatting, it may be best the farther along you are to decrease the weight due to the relaxin that can have your pelvis spread - it’s not fun and you may experience some pain due to the softening of the symphysis pubis or the front of your pelvic bone.

Deadlift, but do it lighter, and watch out doing the Valsalva maneuver. Don’t hold your breath.

Do free weights, but usually, when doing that, your physician will give you a max weight, usually up to 30 pounds (15 each side).

If you have not been lifting prior to pregnancy and want to start, you should talk to your doctor first. I know, I say that about everything. I still believe you can still lift, but you may have to be more careful than the experienced lifter that is pregnant because you may not know proper form and breathing techniques.

Sounds silly, but proper breathing and form are really important. This can be the difference between feeling like crap when you lift (holding your breath and causing blood pressure issues with the Valsalva maneuver) and lifting effectively.

Squatting should be done with free weights or no weights at first. Deadlifts can be done, just make sure they aren’t heavy and you have meticulous form.

Chest press should be done incline and with dumbbells. Anything that goes over the belly you should avoid (weight wise).

Using the machines is also a good tool when you are first starting your lifting career while pregnant. You can adjust the machine to you, and you can adjust how much weight you want to lift easily.

Other Exercises You Can Do While Pregnant

Resistance bands and stability ball workouts can be extremely effective for both the experienced lifter and the novice lifter. Yoga and pilates can be extremely effective for stretching and core work and help ease back pain that is associated with later pregnancy.

Conclusion

There is a lot going on in pregnancy that you have to take into consideration. Pregnancy, however, is not a disease, it is a condition that is a normal part of a woman’s life. We actually were made to be the incubator for a human life, and as such, our bodies go through many changes.

Hormones can affect us tremendously, as well as any complications we may have. This, in turn, can affect our exercise regime.

It is important that your physician is included in the decision to exercise and what their recommendations are based on your past medical history and the like.

References

1) University of Georgia. "Supervised weight training safe for pregnant women, study suggests." ScienceDaily. ScienceDaily, 26 March 2011.
2) Foundations of Maternal-Newborn Nursing, Saunders 4th Ed. 2006
3) Fundamentals of Anatomy and Physiology, Prentice Hall, Upper Saddle River, New Jersey, 4th ed 1998