Starting Early: Why First Trimester Is the Best Time to Begin Moving and Preparing Your Pelvic Floor
If you've just found out you're pregnant, you've may have heard conflicting information on exercise during pregnancy.
However research concludes moderate-intensity exercise starting in the first trimester is safe and may actually improve your pregnancy outcomes — including a higher chance of vaginal delivery and shorter labour.
Exercise in Early Pregnancy Is Safe
The evidence is clear: exercise does not increase miscarriage risk.
A 2025 meta-analysis examining physical exercise across randomised controlled trials found no increased risk of miscarriage, preterm birth, or low birthweight associated with moderate-intensity aerobic or strength exercise performed during pregnancy (Andargie et al., 2025). These findings held true for women starting exercise in the first trimester and continuing throughout pregnancy.
The American College of Obstetricians and Gynaecologists (ACOG 2020) and the Cochrane reviews confirm this: cardiovascular exercise at moderate intensity performed 3–4 days per week from early pregnancy onwards does not compromise maternal or fetal health.
What this means: If you exercised before pregnancy, you can almost certainly keep exercising. If you didn't, pregnancy is a good time to start.
Why Early Exercise Matters
Better birth outcomes. Women who engaged in regular physical exercise during pregnancy had an increased likelihood of normal vaginal delivery, a reduced rate of caesarean delivery, and a shorter first stage of labour compared to those who remained sedentary (Andargie et al., 2025).
Lower risk of pregnancy complications. Aerobic exercise performed 30–60 minutes per session, 2–7 times per week, reduces the risk of gestational hypertension and preeclampsia.
Reduced gestational diabetes risk. A 2017 randomised controlled trial of 300 overweight and obese women found that cycling initiated in the first trimester at 30 minutes, three times weekly, significantly reduced the incidence of gestational diabetes.
Safe Movement in Trimester One
To get the benefits mentioned above, aim for moderate-intensity activity — you should be breathing harder, but still able to talk.
Suitable activities include:
Brisk walking
Swimming
Pilates classes
Yoga
Strength training with appropriate load
The key is consistency: aim for 30–60 minutes per session, at least 3 times per week.
First-trimester-specific caution: Avoid overheating during exercise and drink plenty of water.
The practical version: Build intensity gradually. If you're new to exercise, start with 10–15 minutes and increase as your fitness allows.
Pelvic Floor: Start Now
One of the most valuable things you can do in trimester one is learn how your pelvic floor works and begin basic strengthening.
Your pelvic floor is a group of muscles at the base of your pelvis that support your bladder, uterus, and bowel. During pregnancy, these muscles are doing extra work while also being stretched as your baby grows.
Starting pelvic floor training early makes a real difference. A randomised controlled trial of 169 women found that pelvic floor muscle training (PFMT) taught in a general exercise class three times per week for at least 22 weeks was effective in the primary prevention of urinary incontinence in women having their first baby.
A common concern: Won't strengthening my pelvic floor make birth more difficult?
No. Research specifically addressed this question. A 2024 systematic review and meta-analysis found that pelvic floor muscle training throughout pregnancy did not negatively affect vaginal birth outcomes (Zhang et al., 2024). In fact, training improved women's awareness of how to contract and relax these muscles — a skill that's genuinely useful during labour.
The goal isn't to make your pelvic floor stronger alone. It's to help you understand how to control it — both contraction and relaxation.
What Current Australian Guidelines Say
The Women's Health and Exercise Research group (WHEN) in Australia released updated Recommendations for Exercise and Pregnancy Guidelines in 2025. Their position: exercise is safe and beneficial in the first trimester of uncomplicated pregnancies.
There are no absolute contraindications to exercise in early pregnancy. What matters is individualised assessment and appropriate modification based on your symptoms and fitness level.
How We Support You at Balanced Physiotherapy & Pilates
In trimester one, we focus on pelvic floor awareness and safe, progressive strength and conditioning. We can help you modify your current activities so you can stay as active as you want to be — and advise on what to avoid.
Starting early means prevention, not treatment. Many women wait until pain or symptoms appear to see a physio. Early support often prevents those symptoms from developing in the first place.
The Bottom Line
Pregnancy is not a time to stop moving. The research is consistent: early exercise is safe, and it's beneficial. Starting pelvic floor awareness in the first trimester gives you a strong foundation for the rest of your pregnancy and recovery afterwards.
Ready to plan safe, effective movement for your pregnancy? Book an assessment and we'll create a plan tailored to your body and your goals.
References
Andargie, B. A., Legas, A., W/Sellassie, A., Abuhay, H., & Angaw, D. A. (2025). Effects of physical exercise during pregnancy on delivery outcomes: Systematic review and meta-analysis of randomized controlled trials. PLOS One, 20(7), e0326868. https://doi.org/10.1371/journal.pone.0326868
ACOG Committee Opinion No. 650. (2020). Physical activity and exercise during pregnancy and the postpartum period. Obstetrics & Gynaecology, 135(4), e178–e188. https://doi.org/10.1097/AOG.0000000000003687
Mørkved, S., Bø, K., Schei, B., & Salvesen, K. A. (2003). Pelvic floor muscle training during pregnancy to prevent urinary incontinence: A single-blind randomised controlled trial. Obstetrics & Gynaecology, 101(2), 313–319.
Zhang, X., Gao, L., Tian, H., Li, J., Zhao, Z., & Wu, J. (2024). Influence of pelvic floor muscle training alone or as part of a general physical activity program during pregnancy on urinary incontinence, episiotomy and third- or fourth-degree perineal tear: Systematic review and meta-analysis of randomized clinical trials. Acta Obstetricia et Gynecologica Scandinavica, 103, 1015–1027. https://doi.org/10.1111/aogs.14744
Women's Health and Exercise Research Group. (2025). Recommendations for Exercise and Pregnancy Guidelines. Retrieved from https://when.org.au/wp-content/uploads/2025/05/RecommendationforExerciseandPregnancyguidelines.pdf