Is weight training safe in pregnancy?

So are there any dangers associated with doing squats and lunges during pregnancy?

The ACOG advises on ‘Absolute Contraindications to Exercise During Pregnancy‘:
– Hemodynamically significant heart disease
– Restrictive lung disease
– Incompetent cervix/cerclage
– Multiple gestation at risk for premature labor
– Persistent second- or third-trimester bleeding
– Placenta previa after 26 weeks of gestation
– Premature labor during the current pregnancy
– Ruptured membranes
– Preeclampsia/pregnancy-induced hypertension

They go on to mention that the activities that ‘should be avoided during pregnancy‘ are those that:
– Carry a risk of trauma / have a potential for contact – eg. Ice hockey, soccer, and basketball;
– Carry a risk of falling – eg. Gymnastics, horseback riding, downhill skiing, and vigorous racquet sports;
– Scuba diving, because during this activity the foetus is at increased risk for decompression sickness secondary to the inability of the foetal pulmonary circulation to filter bubble formation.

The ACOG also advises on ‘Warning Signs to Terminate Exercise While Pregnant‘:
– Vaginal bleeding
– Dyspnoea prior to exertion
– Dizziness
– Headache
– Chest pain
– Muscle weakness
– Calf pain or swelling
– Preterm labor
– Decreased foetal movement
– Amniotic fluid leakage

Whether you’re a strength training newbie or a seasoned professional, please remember you must get medical clearance from your health care professional before proceeding with your strength training programme.

There are also some considerations you need to keep in mind when doing strength training during pregnancy:

– Increased body weight: this may increase the forces across joints which could potentially cause discomfort to normal joints and increase damage to arthritic or previously unstable joints;

– Back posture: pregnant women typically develop lumbar lordosis, which contributes to the very high prevalence (50%) of low back pain in pregnant women. This means correct posture during lifting is very important – luckily strength training during pregnancy actually helps to decrease pregnancy-associated low back pain;

– Impaired balance: this is due to altered centre of gravity and impaired signalling from your proprioceptors (the little receptors in your extremities that feedback the positions of your body parts). This theoretically predisposes pregnant women to loss of balance and increased risk of falling;

– Increased ligamentous laxity: this is secondary to the influence of the increased levels of oestrogen and relaxin. Theoretically, this would predispose pregnant women to increased incidence of strains and sprains;

– Lying flat on your back from the 4th month of pregnancy onwards. All that increased weight in your uterus (baby, amniotic fluid, placenta) compress your inferior vena cava (large vein in your body). It can make you feel dizzy and theoretically decrease blood supply to the baby. It should be noted that each pregnant woman’s response to lying flat is different – many women report being able to exercise flat on their backs well into the 3rd trimester; some feel dizzy lying on their backs right from the start;

– Breathing: traditionally many people use the Valsalva technique when lifting (fancy word for holding your breath and essentially straining) – this should be avoided, and you should aim to exhale (breathe out) when you lift/ during muscle (concentric) contraction phase and inhale (breathe in) when you lower the weight/ during muscle relaxation (or eccentric contraction) phase.

I had a look at the evidence looking specifically at weight training during pregnancy. There is a plethora of information on websites / from personal trainers / from people’s personal experiences, but actual well-designed studies? Less so…

I come back to the ACOG guidelines again and they state “in addition to aerobic activities, activities that promote musculoskeletal fitness are part of an overall exercise prescription. Typically, these include both resistance training (weightlifting) and flexibility exercises. Limited information exists on strength training during pregnancy”.

There is one study that individually prescribed strength training (one set of up to 12 repetitions) of multiple muscle groups was used as part of an overall conditioning programme for pregnant women. Foetal heart rates were monitored during training at 28 and 38 weeks gestation, and they remained unchanged. The authors concluded that strength training is advisable during pregnancy.

OK, so far nothing in the guidelines that says you can’t weight train whilst pregnant. Yee haa!

This post is already waaaaaay longer than I originally planned… I know we’re meant to be looking at whether strength training can cause the placenta to separate, so I will continue with placental abruption in the next post… Say tuned!

ACOG guidelines
Hall DC, Kaufmann DA. Effects of aerobic and strength conditioning on pregnancy outcomes. Am J Obstet Gynecol1987;157:1199–203.

If you have found a spelling or grammatical error, please notify me by highlighting that text and pressing Ctrl+Enter.


One Comment

  1. Pingback: Medical News Snippets | Push Ups, Pull Ups & Pregnancy

Leave a Reply

Your email address will not be published. Required fields are marked *