Sophia McDermott Drysdale: Training Pregnant Clients—Avoid These Exercises

Part II of A Trainer’s Guide to Pregnant Clients

As fitness professionals, we are keenly aware that women are routinely given mixed information about training during their pregnancy. Unfortunately, this is partly due to the remaining stigma whereby pregnancy is treated as if it is an illness and women are expected to rest all the time and never exert.

While there is no doubt that pregnancy can take its toll on the body, it is surprising to many that the most tiring phase is often the first trimester, when there are few visible signs. This is when all the initial changes are taking place and the body is working overtime to adjust.

That said, the words first trimester are not an automatic red light for exercise.

Exercise has a myriad of benefits for the mother and the developing baby, which will help throughout pregnancy and during her labor, birth and recovery. Exercise or training programs need to be modified accordingly, rather than being stopped altogether. Knowledge and understanding about the changes in the expectant mother’s body and knowledge about exercises and conditions or situations that should be avoided will help in creating programs that are suitable for clients who are pregnant.

In the first piece of this series, I discussed all the changes that occur in an expectant mother’s body during pregnancy and childbirth. These changes range from the hormonal to physiological, affecting everything from emotions and mood, body temperature and metabolism to hip structure and pelvic alignment.

In this piece, I am focusing on exercises or conditions that should not be performed by any pregnant woman. I will also explain the reasons why they should be shelved. Once the reasons behind their deletion are understood, appropriate modifications can take place to create a safe and effective training program.

As stressed in part one of this series: While the guidance in this article is based on experience, always defer to the instructions of the client’s obstetrician. Send them back to the doctor with a list of questions, but in the moment, go with what the MD says.

The first three months: Why they are the most critical for the development of the fetus
The most crucial phase of the development of the fetus is actually in the first trimester. The first 12 weeks of pregnancy are when the baby’s body is being ‘mapped out,’ so to speak. It is when the nervous system and the internal electrical system are being formed, to enable a tiny heartbeat. It is at this stage when the lungs and abdominal cavity are created to hold the internal organs such as the intestines, liver and kidneys. It is also when the spinal column is formed and fused to create the brain and spinal cord. (1)

The first trimester is also the stage where most deformities or abnormalities occur.

Sometimes birth defects occur naturally and other times they occur because of conditions experienced by the mother that were unsafe for the developing fetus. According to the American College of Obstetricians and Gynecologists (ACOG) studies reveal that anywhere from 10-25% of all clinically recognized pregnancies will end in miscarriage and 80% of these occur in the first 12 weeks. (2)

Obviously there are things that we can’t control, such as genetics, placement of the placenta and embryo or other conditions that may cause a miscarriage. As a coach, we can almost have complete control the training environment for the mother. That said, we must ensure that her situation is as ideal and as healthy as is possible.

Please understand, even though there are not that many structural changes in the mother’s body that warrant the training program to be greatly modified, there are certain circumstances that all trainers need to pay particular attention to during the early stages of a client’s pregnancy.

Dehydration and overheating in the first trimester
Water is absolutely crucial for both the mother and the developing fetus. Water helps to form the placenta that transports nutrients to the baby. The amniotic sac that the baby spends nine months of its development floating in, contains up to 800ml of amniotic fluid. By week 34 it is comprised of mostly water. (3) As discussed in part 1, during pregnancy, the mother’s blood volume doubles in order to transport essential nutrients to the developing fetus. If the mother’s fluid levels are low or she becomes dehydrated, this could lead to minor side effects such as migraines for the mother or more serious issues such as birth defects for the baby.  The amniotic fluid is essential for the development of muscles, limbs, lungs and the digestive system of the fetus. If these levels are low, then this can cause compression of fetal organs, resulting in birth defects.

Neural tube defects are another very common abnormality that happens most often in the first month or so of pregnancy, whereby the neural tube doesn’t close properly and can cause defects of the brain, spine or spinal cord. The most common neural tube defect is Spina bifida. (4)

During pregnancy, the mother’s metabolism increases, elevating her basal body temperature. A hard workout, coupled with dehydration, is a recipe for hyperthermia. Since the baby does not have the ability to cool itself down in any way inside the mother’s body, this can be a serious issue and could lead to deformities or miscarriage.

As a trainer it is essential that you encourage your client to drink plenty of water while exercising. She needs to be drinking at least a gallon a day and if she is working out, then possibly a gallon and a half. It is also essential that she performs her workouts in a cool environment and takes intervals of rest during her workout to avoid overheating.

Adjustments for the second and third trimesters
Although the second and third trimesters are considered less risk for the developing fetus, the trainer needs to make modifications for more structural changes in the mother’s body.

Cardio and heart rate
The mother’s blood volume increases by a whopping 40-50% during pregnancy and her heart rate increases up to 15% to about 80-90 beats per minute.  She also requires more oxygen at each breath. This means that the mother is working 40% harder to pump more blood at each beat to circulate to the uterus during pregnancy just at rest. (5)

When you factor in exercise, this increase in physical exertion will result in a dramatically increased breathing rate, making the mother feel significantly out of breath.  Doctors rarely provide a recommended heart rate for pregnant women while they are exercising (140 beats per minute used to be the standard.)

Guidelines should be based on how your client is feeling and whether she can hold a conversation while exercising. If she is finding it hard to talk, then that is your cue to tone it down a notch. Overexertion can lead to oxygen deprivation for the baby, so if your client is experiencing dizziness, faintness, chest pain, cramping or vaginal bleeding, stop exercising immediately.

Dehydration and preterm labor
In the later stages of pregnancy, dehydration and lower amniotic fluid levels can cause severe cramping in the uterus for the mother and can bring on premature contractions. More serious complications include intrauterine growth restrictions, whereby fetal weight is below the 10th percentile for gestational age and premature birth. (6) If your client is starting to feel pain in the uterus or experiencing contractions, this may be because she is dehydrated. Stop exercising immediately, drink lots of water and monitor the contractions.

Exercises to avoid

Lying flat on your back
During the later stages of pregnancy, expectant mothers should avoid exercising flat on their backs or lying supine. This position puts pressure on one of the main veins that transports blood from the legs and feet and pelvis back to the heart known as the inferior vena cava. This slows down the blood flow to the placenta and limits the oxygen and nutrients delivered to the baby. Avoid movements that place the mother on her back particularly in the third trimester. (7)

Exercises that should absolutely be avoided are the bench press and chest press variations (especially decline chest press). Other exercises such as abdominal exercises where the mother is lying flat on her back should also be avoided.

During the second half of the pregnancy it is important not to perform exercises that involve lying flat on your back since this places pressure on the inferior vena cava which can limit blood flow to the placenta.

During the second half of the pregnancy, it is important to not perform exercises that involve lying flat on your back, since this places pressure on the inferior vena cava, possibly limiting blood flow to the placenta.

Lying flat on your stomach
As the baby grows, expectant mothers should also avoid lying flat on their stomachs or prone for obvious reasons. Although the baby is heavily cushioned by the amniotic sac, lying flat on the stomach will place undue pressure on the uterus and limit blood flow.

In the second trimester and especially in the third trimester, avoid all exercises that involve lying prone such as superman raises, or hamstring curls.

Although the baby is heavily cushioned in its amniotic sac, avoid performing any exercises that involve lying flat on your stomach. This places far too much pressure on the uterus.

Although the baby is heavily cushioned in its amniotic sac, avoid performing any exercises that involve lying flat on your stomach. Doing so places far too much pressure on the uterus.

Abdominal exercises
During the earlier stages of pregnancy, abdominal exercises, in particular transverse abdominal exercises, such as plank hold variations are fine to perform. The reason why I suggest transverse ab exercises is that these muscles are used in childbirth and may make for an easier birth.

However, as the baby grows and the abdominals stretch and become weaker during the second and third trimesters, most abdominal exercises should be avoided. Many women experience Diastasis Recti, which is a complete separation of the rectus abdominis muscles. The gap down the centerline can be up to three inches wide is some women.  Although this not painful, per se, it does contribute to major weakness.  Performing any abdominal exercises can put excessive strain on the abdominals as well as the lower back, which is working overtime to support the spine. The anterior pelvic tilt that often comes along with the forward weight displacement also puts a lot of pressure on the lower lumbar region. This lower back area needs to be stretched and released, rather than contracted.

Performing sit-ups while flat on your back should be avoided as well as crunches with any weight on the chest or abdomen. More challenging plank hold exercises should be modified to avoid excessive strain on the abdominals and the lower back. These exercises can also put considerable pressure on the diaphragm, making it harder to breathe. Even and regular breathing is essential for the health of the baby.

Performing sit ups while pregnant in the second half of the pregnancy will cause too much pressure on the uterus and lower back. Try to avoid direct abdominal exercises in the latter half of the pregnancy.

Performing sit ups in the second half of the pregnancy will cause too much pressure on the uterus and lower back. Try to avoid direct abdominal exercises in the latter half of the pregnancy.

Weightlifting/Resistance Training
There has been a lot of contention surrounding pregnant women lifting weights. Most medical professionals will advise not to lift weights. I believe much of the issue is not the resistance training as such, but in incorrect breathing when lifting weights and the overall force exerted and poor posture.

Often, when clients are lifting heavy loads, they hold their breath. This leads to moments of high blood pressure, which can restrict blood flow to the baby.  Compound movements with heavy loaded weight that place a lot of force on the core, such as deadlifts and squats place undue stress on the uterus and should be avoided. The focus should be on performing movements with lighter weight and body weight only exercises.

Make sure your client has good posture, is performing the movement smoothly and is breathing correctly throughout each repetition. By modifying the training program and adjusting the weights, your client can still receive all the benefits from performing resistance training.

Single-leg movements and wide side stepping
During the later stages of pregnancy, the hormones progesterone and relaxin help to loosen the ligaments and joints, to widen the pelvis in preparation for childbirth. The joints become hyper mobile causing less stability, which could potentially lead to injury. Many women experience pubis symphysis dysfunction whereby the ligaments at the front of the pelvis soften and widen which can be extremely painful. It is best to avoid exercises that involve movement on a single leg or staggered stance such as lunges and steps ups. Avoid wide side steps also. These movements exacerbate the pain and are difficult to carry out due to the lack of stability in the pelvis.

Performing exercises in a staggered stance can be very painful in the pubis symphosis since the ligaments that connect the pelvis are loose and unstable.

Performing exercises in a staggered stance can be very painful in the pubis symphosis, since the ligaments that connect the pelvis are loose and unstable.

Ballistic movements
Some of your clients may be avid runners or aerobic enthusiasts. High impact movements can put too much pressure on the joints that are already hyper mobile because of the relaxin. Lots of bouncing and ballistic stretches should be minimized.

Try to keep the movements steady and smooth and opt for low impact options such as uphill walking or bike riding as an alternative.

If you are a trainer or a coach and have clients or students who are pregnant, it is absolutely crucial that you know and understand the many changes that are going on in your client’s body at the time, enabling you to gauge and monitor your client’s health and well-being at all times.

It is also important to know what conditions and specific exercises or movement patterns to avoid and why, so that you can safely prescribe and guide your client through her sessions during her pregnancy. Basically, you should be providing a training environment that is cool, allowing plenty of water breaks so your client doesn’t overheat, become out of breath or dehydrated. This is essential.

Towards the later stages of pregnancy, movements placing your client flat on her back or flat on her stomach should be avoided. Abdominal exercises and compound movements such as heavy deadlifts and squats should be avoided, due to the overall exertion and therefore the pressure they place on the mother’s core, lower back and uterus. Side stepping and single leg movements should be limited due to pubic symphysis dysfunction and ballistic movements should be minimized and replaced with low impact movements so as not to place undue stress on loose joints.

Remember to listen to mother, always listen to her feedback and modify accordingly during the sessions. This is very important for the health of the mother, baby and the long term trust and rapport between trainer and client. Your client must feel comfortable enough to continue training throughout her pregnancy and postpartum.

More from Sophia McDermott Drysdale at OTP:

Sophia McDermott Drysdale: A Trainer’s Guide to Pregnant Clients

Sophia McDermott Drysdale: 6 Reasons Why ALL Women Should Perform Resistance Training

More on training pregnant clients from OTP:
Training Through Pregnancy, Personal Training For New Mothers, How To Train A Pregnant Client

Galina Denzel: Training the Pregnant Client

Tips for Fitness Pros:
Rachel Cosgrove Fitness Pro - How To Become A Fitness Pro - Women Fitness Pros
Rachel Cosgrove: Seven Secrets for Women Fitness Pros


  1. Pregnancy Day By Day. Maggie Blott MD, 2009, New York. DK Publishing. Page 141
  2. American Pregnancy Association, Miscarriage.
  3. U.S National LIbrary of Medicine. Neural Tube Defects
  4. 4.The Encyclopedia of Genetic Disorders and Birth Defects, By James Wynbrandt, Mark D. Ludman, Published in NY, USA, 2007
  5. Blood volume changes in normal pregnancy. October 1985
  6. American Pregnancy Association. Low Amniotic Fluid Levels: Oligohydramnios
  7. WebMD, Good Posture During Pregnancy.

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