As long as there are no contraindications (reasons you should not be exercising - informed by your midwife or obstetrician) exercise in pregnancy guidelines have been published (1) and in this post we will summarise the findings. Exercise in pregnancy is associated with fewer newborn complications and a huge host of health benefits for mother. These guidelines are the most recent to be published and take in to account an extensive amount of clinical research (1). You should speak to your medical ante-natal team (midwife, doctor, obstetrician or physiotherapist) BEFORE commencing any exercise programme if you have any of the following contraindications (or any other concerns regarding exercising whilst pregnant). If you have any of the relative contraindications you may be allowed to exercise under obstetric advice: Contraindications to exercise during pregnancy:
Ruptured membranes
Intrauterine growth restriction
Premature labour
High-order multiple pregnancy (eg. triplets)
Unexplained persistent vaginal bleeding
Uncontrolled Type I diabetes
Placenta previa after 28 weeks
Uncontrolled hypertension
Pre-eclampsia
Uncontrolled thyroid disease
Incompetent cervix
Other serious cardiovascular, respiratory, systemic disorders
Relative contraindications to exercise during pregnancy:
Recurrent pregnancy loss
Malnutrition
Gestational hypertension (high blood pressure during pregnancy)
Eating disorder
History of spontaneous preterm birth
Twin pregnancy after the 28th week
Mild/moderate cardiovascular or respiratory disease
Other significant medical conditions
Symptomatic anaemia
Antenatal Exercise Guidelines (2019) (1): 1. All women without contraindication (see above) should be physically active throughout their pregnancy. Exercising from the first trimester (first 12 weeks) onwards is associated with reduced odds of developing pregnancy complications such as gestational diabetes mellitus, pre-eclampsia, gestational hypertension, prenatal depression and macrosomia (1). In fact, those who do not exercise during the first trimester were found to have greater odds of developing these complications. Exercise during the first trimester (and onwards) does not increase the odds of adverse outcomes such as preterm birth, low birth weight, miscarriage or perinatal mortality (1). This will hopefully reassure pregnant women about the safety of their engagement with exercise. 2. Pregnant women should exercise for a minimum of 150 minutes (accumulated total) per week. Exercise can be broken down in to manageable amounts, even 10 minute bursts will count. You should always ensure you feel well enough during and after exercise, and be able to hold a conversation throughout exercise. This is a good way to measure your breathlessness / level of exercise intensity. 3. Physical activity should be accumulated over a minimum of 3 days per week. Being active every day is strongly encouraged and more activity is associated with many health benefits. No upper limit has been established in the clinical research, however it is best to seek advice from your ante-natal medical team to ensure you do not do too much. If you feel unwell, dizzy or light headed - stop. Re-consider the exercise you were doing and perhaps find an alternative that is slower paced or more gentle. Swimming, walking, yoga, and pilates are all great exercise forms that you can do throughout pregnancy and modify to suit how you are feeling. This may be different day to day, listen and respect to your changing body. 4. Physical activity should include a combination of aerobic exercise, resistance training and gentle exercise such as Yoga or Pilates. This combination is proven to be more effective than aerobic exercise alone. This mixed approach will provide cardio, strength training and relaxation. This gives a comprehensive workout plan and will provide full benefits to mother and baby. Aerobic exercise is important so that the cardiovascular system is exercised (helps with heart & lung health as well as labour endurance); strength work ensures a strong body both to support your growing bump and posture changes, but also to cope with the demands of caring for a baby 24/7 soon. The gentle exercise is recommended for helping with mental health.
5. Pelvic floor muscle training should be performed daily.
Pelvic floor exercises should commence from the start of you pregnancy where possible (2). Ideally these exercises should be practised 3-4 times per day for adequate muscle training and long term benefits. These should consist of 10 repetitions of both the FAST squeezes and SLOW squeezes each time (2). The NHS Squeezy App provides an excellent tool for remind you to complete the recommended amount of exercises, and advising how to complete them.
6. Pregnant women who experience light headedness, nausea, or feeling unwell when exercising on their back should adopt an alternative position or alternative exercise.
Exercising in supine (flat on your back) should be avoided after the first trimester. This is because it can be associated with a reduction in oxygen to the baby and potentially concerning fetal responses. The outcomes vary based upon time spent on your back, and whether this was static or dynamic (moving), a one off episode or a regular exercise. The research suggests it is avoided beyond 12 weeks to eliminate any concerns (2). Here is a link to a guide I produced on instagram.
Aerobic exercise guidelines
The general clinical consensus is that if you are used to aerobic exercise then you can continue in pregnancy, and monitor yourself. Research has only been done on exercise sessions up to 60 minutes, so there is no upper limit established. This is not to say you cannot exercise for longer, but be cautious, and only carry on with what you were comfortable doing this before pregnancy. Pregnancy is not the time to increase exercise levels.
Recommended heart rate details: The average heart rate 'safe zone' for pregnant women for moderate exercise is within 40-59% of your heart rate ratio. For vigorous exercise it is 60-80%. However, the easiest & main measure should be the Talk Test. You should be able to hold a full conversation at any stage during your exercise and afterwards.
Strength training guidelines
For those used to weight-lifting prior to pregnancy it is acceptable to continue lifting light to moderate weights provided there are no complications. Evidence suggests that continued exercise has a positive effect on the fetus as it learns to regulate its heart rate in response to stress, and newborn stress following birth is reduced in those women who exercise at 50% their pre-pregnancy levels (3).
For the athlete who wishes to perform heavy lifts they must consider several factors. Firstly the excess load can pressurise the pelvic floor and lead to pelvic floor dysfunction and prolapse. Secondly, risks to the baby may occur during the valsalva manoeuvre- where blood pressure is elevated during straining. This increases the internal pressure (intra-abdominal pressure) and can cause a transient reduction in blood flow to the baby (3) .
How to begin exercising when pregnant
Always get clearance from your ante-natal medical team (midwife or obstetrician) first & follow exercise advice from a Chartered Physiotherapist trained in ante and postnatal exercise (such as us).
Begin slowly and gradually so that you can evaluate the effects on your body, respecting the changes you are experiencing with a growing bump.
Begin with pelvic floor and core muscle activation exercises. Pilates is excellent for teaching you this, as well as strengthening & mobility exercises for your whole body.
Walking is the easiest way to begin aerobic training. Gradually increasing the duration and pace as able. Swimming is also highly suitable and reduces the pressures on your body later in pregnancy.
Lifting weights can be introduced for strength work, ensuring your technique is safe, and the weight is light to begin with.
Key Points Any exercise during pregnancy is better than nothing. If you feel good, it is generally safe. Certain positions should be adopted with care and lighter weights or resistance is recommended. Ensure you can talk throughout & just after your exercise session. A combination of aerobic, strength, and gentle Pilates or Yoga is recommended and a little every day is the most beneficial for you and your baby. If you have any questions, please do not hesitate to get in touch. Book an appointment if you would like bespoke and individual help to support your pregnancy with exercise.
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References
1) 2019 Canadian guideline for physical activity throughout pregnancy
2) Fit for Pregnancy (POGP guidelines)
3) ACOG practice bulletin: Intrapartum Fetal Heart Rate Monitoring