Exercise during pregnancy: strength, cardio and what to avoid according to the evidence
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An analysis of 106 studies with more than 270,000 pregnant women found that exercise lowers the odds of gestational diabetes, hypertension and pre-eclampsia. What guidelines recommend, whether you can keep lifting, how to adjust strength work in each trimester and when to stop.
In 2018, a University of Alberta team led by Margie Davenport pooled 106 studies covering 273,182 pregnant women to answer a specific question: does exercise prevent the most common complications of pregnancy? In the randomised trials that added exercise alone, the odds of gestational diabetes fell by 38%, those of gestational hypertension by 39% and those of pre-eclampsia by 41%.
For decades, many women were told the opposite: rest, no lifting and keep your heart rate low. Current clinical guidelines say something else. Here is what exercise is recommended, whether you can keep lifting weights, what to adjust in each trimester and when you should stop.
Is it safe to exercise during pregnancy?
If the pregnancy is uncomplicated, yes. The 2019 Canadian guideline, coordinated by Michelle Mottola (University of Western Ontario), reviewed the available evidence and concluded that the benefits of prenatal exercise are moderate and that no harms were identified. The American College of Obstetricians and Gynecologists (ACOG) reaches the same conclusion in its 2020 committee opinion: without obstetric or medical complications, physical activity in pregnancy is safe and desirable, and women who already did vigorous exercise can carry on.
That does not mean anything goes. It means the starting point is no longer “don't move” but “move and adjust”.
| Source | What it concludes | What it means in practice |
|---|---|---|
| Canadian guideline (Mottola, 2018) | Moderate benefits of prenatal exercise; no harms identified | Moving is the default if there are no contraindications |
| ACOG (2020) | Without complications, exercise is safe and desirable; women who trained hard can continue | There is no need to stop when you find out you are pregnant |
| Davenport (2018), 106 studies | 600 MET-min a week of moderate intensity cut the odds of gestational diabetes, hypertension and pre-eclampsia by at least 25% | About 140 minutes a week of brisk walking, stationary cycling, water aerobics or strength training |
| WHO (2020) | First specific recommendations for pregnancy and the postpartum period; muscle strengthening for all age groups | Strength work is part of the recommendation, not an extra |
Can you lift weights while pregnant?
It is the most common question in the gym and the one with the fewest studies. The classic warnings (no Olympic lifting, no breath-holding with the Valsalva manoeuvre, no training lying on your back) were based on expert opinion rather than data, as Prevett, Davenport and colleagues point out in a 2023 paper.
That study surveyed 679 women who had lifted loads of at least 80% of their maximum (1RM) during pregnancy, most of them doing CrossFit or weightlifting. 66% had no complications during pregnancy or delivery, and those who kept their training level until the end reported fewer complications than those who cut back earlier. Doing or avoiding Olympic lifts, the Valsalva manoeuvre or lying-down exercises did not change the outcomes.
How to read this: it is a survey of women who already trained hard and chose to continue, with no comparison group. It suggests heavy lifting is not harmful in trained women without complications; it is not an invitation to chase personal records in the third trimester.
For most women, the sensible goal is to maintain: loads that leave 2-3 reps in reserve, clean technique and continuous breathing. If you are not sure how to judge that reserve, we explain it in RIR and RPE.
Lying on your back, abs and balance
- Lying on your back: the 2023 survey found no worse outcomes in women who trained in that position, but if you feel dizzy, nauseous or short of breath lying down, switch to an incline bench or a standing version.
- Abs: as the bump grows, crunches and long planks become more and more uncomfortable. The Pallof press, the bird dog or a plank with your hands on a bench are easier alternatives.
- Balance: your centre of gravity shifts. Exercises with a risk of falling or a blow to the abdomen are no longer worth it; machines, cables and stable supports gain ground.
The pelvic floor: the muscle that deserves most attention
57% of the women in that survey reported urine leakage after giving birth. Here there is a trial showing how to reduce it. In 2025, Rubén Barakat's group at the Technical University of Madrid followed 356 pregnant women: half did a supervised programme of moderate exercise, 3 days a week and 60 minutes per session from week 8-10 to week 38-40, including pelvic floor training. That group had less urinary incontinence at the end of pregnancy and 3 months after delivery than the control group.
In practice, it means building pelvic floor contractions into your routine, without squeezing your glutes or holding your breath. If you are unsure how to do them, a pelvic health physiotherapist can check in a single appointment.
When you should not exercise (or should change what you do)
The classic list of contraindications has also been revisited. In 2020, Meah, Davies and Davenport analysed 44 studies and found that most conditions considered incompatible with exercise rested on expert opinion, with very little data showing actual harm. They identified 11 complications, such as gestational hypertension or twin pregnancy, in which adapted physical activity might be beneficial. And they kept as absolute those with a clear risk.
| Category | Conditions | What to do |
|---|---|---|
| Absolute contraindication | Severe cardiorespiratory disease, placental abruption, vasa previa, uncontrolled type 1 diabetes, intrauterine growth restriction, active preterm labour, severe pre-eclampsia, cervical insufficiency | Do not train unless your medical team explicitly says so |
| Formerly contraindicated, now to be assessed | For example, gestational hypertension or twin pregnancy | Decide with your obstetrician or midwife which exercise and at what intensity |
Beyond that list, stop the session and seek advice if you notice vaginal bleeding, fluid leakage, regular contractions, severe dizziness, chest pain or breathlessness out of proportion to the effort.
How to adjust your strength routine in each trimester
| Trimester | What usually changes | Sensible adjustments |
|---|---|---|
| First | Tiredness and nausea | Cut volume on bad days; keep your usual exercises if they feel fine |
| Second | The bump starts to show and balance changes | Replace face-down exercises; use an incline bench if lying flat makes you dizzy; more machines and cables |
| Third | More weight, less room and more fatigue | Moderate loads with 2-3 reps in reserve or more, comfortable ranges and more walking |
A full-body session that usually works in the second and third trimesters, with 2-3 sets of 8-12 reps per exercise:
- Box or bench squat: the support sets the depth and adds confidence.
- Cable or band row: counters the tendency for the shoulders to round forward.
- Incline dumbbell press: the alternative to the flat press when lying down feels uncomfortable.
- Glute bridge with your back on a bench: keeps the torso raised.
- Pallof press: core work without crunches.
- 20-30 minutes of walking or stationary cycling on non-strength days.
After the birth
In the 2023 survey, 89% went back to lifting after giving birth, on average at 3.2 months. The pace depends on the type of delivery, the pelvic floor and how much sleep the baby allows: the sensible approach is to return with light loads and build up as your body responds, with a pelvic floor check if possible. ACOG also notes that physical activity helps prevent postpartum depression; how strength training affects mood is covered in weight training, anxiety and depression.
The Progrevia generator does not take pregnancy into account: if you use it, go over the routine with your midwife or obstetrician and apply the adjustments in this article. To understand how performance and recovery change with hormones outside pregnancy, see menstrual cycle and training, and for later on, exercise during menopause.
- Davenport MH, Ruchat SM, Poitras VJ, et al. Prenatal exercise for the prevention of gestational diabetes mellitus and hypertensive disorders of pregnancy: a systematic review and meta-analysis. British Journal of Sports Medicine. 2018;52(21):1367-1375.
- Mottola MF, Davenport MH, Ruchat SM, et al. 2019 Canadian guideline for physical activity throughout pregnancy. British Journal of Sports Medicine. 2018;52(21):1339-1346.
- American College of Obstetricians and Gynecologists. Physical activity and exercise during pregnancy and the postpartum period: ACOG Committee Opinion, Number 804. Obstetrics & Gynecology. 2020;135(4):e178-e188.
- Bull FC, Al-Ansari SS, Biddle S, et al. World Health Organization 2020 guidelines on physical activity and sedentary behaviour. British Journal of Sports Medicine. 2020;54(24):1451-1462.
- Prevett C, Kimber ML, Forner L, de Vivo M, Davenport MH. Impact of heavy resistance training on pregnancy and postpartum health outcomes. International Urogynecology Journal. 2023;34(2):405-411.
- Zhang D, Sánchez-Polán M, Silva-Jose C, et al. Prenatal exercise decreases urinary incontinence in late pregnancy and 3 months postpartum: a randomized controlled trial. Medicine & Science in Sports & Exercise. 2025;57(3):555-562.
- Meah VL, Davies GA, Davenport MH. Why can't I exercise during pregnancy? Time to revisit medical 'absolute' and 'relative' contraindications: systematic review of evidence of harm and a call to action. British Journal of Sports Medicine. 2020;54(23):1395-1404.
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Frequently asked questions
Can I start exercising if I did not before pregnancy?
Yes, if the pregnancy has no complications. ACOG encourages women both to continue and to start. It makes sense to begin with walks and light strength work and build up to about 140 minutes a week of moderate intensity.
Is lifting weights while pregnant dangerous?
In trained women without complications, the available data show no harm: in a survey of 679 women who lifted at least 80% of their maximum, 66% had no complications. Even so, the sensible approach is to maintain rather than chase records, leaving 2-3 reps in reserve.
Can I do exercises lying on my back?
The warnings were based on expert opinion and the 2023 survey found no worse outcomes. If you feel dizzy, nauseous or short of breath lying down, switch to an incline bench or a standing version.
Which exercises should I avoid during pregnancy?
Those with a risk of falling or a blow to the abdomen and, from the second trimester, face-down exercises. With absolute contraindications, such as placental abruption or severe pre-eclampsia, you should not train unless your doctor says otherwise.
When can I go back to the gym after giving birth?
It depends on the delivery and the pelvic floor. In the 2023 survey, women who trained hard returned on average at 3.2 months. It is wise to start with light loads and, if possible, have your pelvic floor checked first.
Informational content based on the available scientific evidence: it does not replace advice from a healthcare professional. If you have an injury or a medical condition, or are pregnant, check with one before changing your training or diet.
