Resistance training is associated with decreased musculoskeletal complaints (less low back pain and prenatal discomfort) and increased connective tissue strength (easier healing in the postpartum) for the mother. Moderate intensity exercise throughout pregnancy tends to result in shorter durations of labor, as well as a decreased risk of both preeclampsia and gestational diabetes. Additionally, babies tend to be longer and denser in lean muscle mass, making them more apt to handle the stresses of labor effectively. While resistance training can be extremely beneficial for prenatal mothers and their babies, one must approach any prenatal lifting regimen or program with the appropriate mindset, awareness, and expectations. A failure to consider these factors can unfortunately lead to injury.
When approaching a lift during pregnancy, there are several general guidelines to consider to determine what modifications may need to be made in order to safely perform the lift. The most important consideration will be to maintain optimal form throughout the entire lift to decrease the risk of injury. The appropriate effort level, posture, breathing, support, and awareness of the bump, as covered in the remainder of this article are a guideline to assist the prenatal mother in conducting safe, injury free lifts throughout pregnancy.
Training During Pregnancy: General Guidelines
Effort Level: Moderate Intensity, 70% of 1RM
Starting in the first trimester, the hormone Relaxin is secreted in the pregnant body, resulting in increased joint laxity. This joint laxity allows the ligaments of the pelvis to loosen and ultimately create the space for a baby to pass through the birth canal during labor. Unfortunately, Relaxin does not only target the joints of the pelvis, but instead it effects the entire pregnant body. Joint laxity increases mobility but decreases the overall stability of a joint. With that being said it is imperative to focus more attention on form during lifts than the weight on the bar.
The lift should be challenging, but not to the point of failure. Exercises at 95-100% of max effort or to the point of exhaustion reduce blood flow to the placenta, increases uterine contractility, and decrease oxygen supply to the baby. Continued exercise at high levels of effort tend to result in significant reduction of fetal growth.
When developing a prenatal strength program repetition ranges should be around 8-12 at 2-4 total sets for a muscular endurance focus. Additionally, super-setting a stabilization exercise with each strength movement will further reinforce the stabilization aspect of training. Example: 3 rounds of 12x Back Squats + 10x Alternating Step Ups.
The set-up for the lift will influence form throughout the lift. Focus on the rib cage being aligned over the pelvis in the relative plane (horizontal for a bench press and vertical for a squat). The pelvis should be in a generally neutral position, with the anterior superior iliac spine, ASIS, (aka the hip bones) aligned with the pubic symphysis (hard boney area on the front of the pelvis). The ribs and pelvis should maintain the same distance from each other throughout the entire lift.
Breathing: Exhale on Exertion
Diaphragmatic breathing stabilizes the spine. As one inhales, the diaphragm moves down and out, increasing the pressure within the abdominal cavity. In response, the abdominals, back, and pelvis floor expand outward. This increased pressure stabilizes the spine during inhalation. As one exhale, the pelvic floor, abdominals, back, and diaphragm contract up and in, returning to their original locations. The increased muscular force stabilizes the spine during exhalation.
During the eccentric portion of the lift (usually the descent or lower), focus on inhaling fully. The abdominal cavity should expand outwards, to include the pelvic floor. During the concentric portion of the lift (usually the ascent, press, or push), focus on exhaling by contracting the pelvic floor, abdominals, and back up and in. Coordination of breath with movement increases stability during lifts.
Do not hold the breath during lifts! Breath holding increases maternal heart rate and blood pressure that may have a negative effect on the baby. In addition, breath holding tends to result in bearing down (increased downward pressure) on the pelvic floor during lifts, which can result in prolapse or pelvic floor dysfunction during pregnancy and the postpartum.
There may be a need to increase the support of a lift in order to accommodate for increased joint laxity, comfort, and mobility. Increasing the support includes:
- Seated Position: When standing or kneeling, be aware of the position of the pelvis and legs during movement. Sitting allows one to focus on the movement in the upper body. This could include doing seated strict press or lat pull downs as opposed to a standing strict press or pull up.
- Bring the floor to you to decrease the necessary range of motion. This could include box squats or elevated deadlifts.
- Increasing the points of contact to increase stability. Two legged movements are more stable than single leg movements. Both the knee and hand on the bench is more stable than one hand or no bench support. If stability is the issue, increase the number of limbs in contact with a sturdy surface.
The pregnancy bump will get in the way at a certain point, so make room for it.
During the first trimester most lifts will look the same as pre-pregnancy, so less modification will be required as significant external changes have yet to occur. Most of the first trimester modifications and considerations will be as a result of internal physiological adaptations, such as:
- Increased Relaxin contributing towards joint laxity and instability prior to external signs of pregnancy.
- Morning sickness or decreased appetite resulting in decreased caloric intake and nutrient density. May need to decrease activity level to account for the decreased caloric intake for overall energy expenditure.
- Increased blood vessel dilation resulting in fatigue and lightheadedness. During the late first trimester to early second trimester, blood volume will double approximately from pre-pregnancy levels. This takes a few weeks as blood vessels will first dilate (widen), while generating a, “we are underfilled,” response in the circulatory system. This is what results in the initial fatigue, and should be considered when exercising during the first trimester.
During the second trimester and third trimester, accommodating for the belly will be necessary. This may include:
- Widening the stance in lower body exercises
- Adjusting to using primarily dumbbells or kettlebells for movements that the belly would impede the bar path, such as Olympic lifts or bent over rows
Overall, lifting throughout pregnancy is beneficial for both mother and baby, but there are several guidelines that should be considered to ensure that the mother is safely making lifts in a manner that support her pregnancy, birth, and eventual recovery in the postpartum.
Gina Conley, CD(DONA), CPT | MamasteFit & The Doulas of Mamaste
- White, E., Pivarnik, J., & Pfeiffer, K. (2014). Resistance Training during Pregnancy and Perinatal Outcomes. Journal of Physical Activity and Health, 11(6), 1141-1148. doi:10.1123/jpah.2012-0350
- Schoenfeld, B. (2011). Resistance Training During Pregnancy: Safe and Effective Program Design. Strength and Conditioning Journal, 33(5), 67-75. doi:10.1519/ssc.0b013e31822ec2d8
- Newton, E. R., & May, L. (2017). Adaptation of Maternal-Fetal Physiology to Exercise in Pregnancy: The Basis of Guidelines for Physical Activity in Pregnancy. Clinical Medicine Insights: Womens Health, 10. doi:10.1177/1179562×17693224
- Clapp, J. F., & Cram, C. (2012). Exercising through your pregnancy. Omaha, NE: Addicus Books.