Get prediction

Exercise in Pregnancy: What's Safe

Exercise is generally safe and beneficial during pregnancy, and keeping active can help manage many common pregnancy symptoms. Here is what you need to know about exercising safely in the first trimester and beyond.

Table of Contents

  1. NHS Guidelines
  2. Safe Exercises (First Trimester)
  3. Benefits of Exercising in Pregnancy
  4. Exercises to Avoid
  5. Modifying Your Workout
  6. When to Stop Exercising

NHS Guidelines

The NHS recommends at least 150 minutes of moderate-intensity activity per week throughout pregnancy, spread across the week. This guidance applies whether you were active before pregnancy or not. Moderate intensity means you can hold a conversation but feel your heart rate has risen — a good rule of thumb is the "talk test."

If you exercised regularly before pregnancy, you can usually continue at a similar level in the first trimester, adjusting as your body changes. If you are new to exercise, this is a good time to start gently — walking is an excellent starting point. Always let your midwife or GP know that you exercise so they can flag any specific reasons to modify your routine.

Safe Exercises (First Trimester)

The following activities are generally considered safe throughout pregnancy, including the first trimester:
  • Walking — easy to fit around daily life and very low impact
  • Swimming and aqua aerobics — the water supports your weight and reduces joint strain
  • Stationary cycling — safer than road cycling as there is no fall risk
  • Pregnancy yoga — supports flexibility and teaches breathing techniques useful for labour
  • Pilates — builds core strength and pelvic floor awareness; choose a pregnancy-specific class
  • Low-impact aerobics — dedicated pregnancy classes are widely available in the UK
  • Light resistance work and bodyweight exercises — generally fine if familiar, with modifications

Always listen to your body, drink water before and during activity, and stop if you feel unwell.

Benefits of Exercising in Pregnancy

Regular moderate exercise during pregnancy is associated with a range of benefits for both you and your baby. For you, it can help manage fatigue and improve sleep, reduce back pain, support your mental wellbeing, manage healthy weight gain, lower the risk of gestational diabetes, and prepare your body physically for labour and recovery. It also helps maintain cardiovascular fitness, which can make the later stages of pregnancy more comfortable. For your baby, the evidence suggests that babies born to regularly active mothers tend to have healthy birth weights.

That said, every pregnancy is different. If you have pregnancy complications such as placenta praevia, a history of preterm labour, or have been advised to rest, always follow your midwife's or consultant's specific guidance over general recommendations.

Exercises to Avoid

Certain activities carry risks in pregnancy and are best avoided:
  • Contact sports (football, rugby, martial arts) — risk of abdominal impact
  • Scuba diving — pressure changes are unsafe for your baby
  • Hot yoga or hot Pilates — overheating in pregnancy carries risks, particularly in the first trimester
  • High-altitude exercise (above 2,500 metres) unless you are acclimatised
  • Horse riding, skiing, snowboarding, and gymnastics — significant fall risk
  • Exercises lying flat on your back after around 16 weeks — the weight of your uterus can compress a major blood vessel in this position, reducing blood flow

If you have any pregnancy complications, always discuss exercise with your midwife before continuing or starting a routine.

Modifying Your Workout

As your pregnancy progresses you will naturally need to modify what you do. In the first trimester, nausea and fatigue may mean you exercise less than usual — that is completely normal. Try shorter sessions if a full workout feels too much.

Practical adjustments worth making throughout pregnancy:

  • Reduce intensity if you feel nauseous or dizzy; aim for moderate rather than vigorous effort
  • Eat a light snack before exercise to prevent blood sugar dips, which worsen nausea
  • Drink water before, during, and after to stay hydrated
  • Wear supportive footwear and a well-fitted sports bra
  • Warm up and cool down gently each session
  • Avoid exercising in hot or humid environments to prevent overheating

As your bump grows, your centre of gravity shifts. Activities that require balance — cycling, certain yoga poses — may need swapping for safer alternatives. A qualified pregnancy fitness instructor can help you adapt your programme.

When to Stop Exercising

Stop exercising immediately and contact your midwife or early pregnancy unit if you experience any of the following:
  • Vaginal bleeding or spotting
  • Sudden or severe abdominal pain
  • Dizziness, faintness, or feeling like you might collapse
  • Painful swelling or calf pain (which could indicate a clot)
  • Chest pain or severe shortness of breath
  • Reduced or absent fetal movements (in later pregnancy)
  • Contractions, or if your waters break

If you are unsure whether a symptom is serious, it is always better to get checked. Call your midwife or 111 for non-urgent concerns.

Frequently Asked Questions

### Can I run in early pregnancy?

Yes, if you were running regularly before pregnancy you can usually continue in the first trimester. Slow your pace if you feel nauseous, breathless, or very tired, and avoid running on very hot days. Wear good trainers and a supportive bra. If you were not running before pregnancy, start with brisk walking rather than beginning a running programme for the first time while pregnant.

Can I do HIIT or CrossFit while pregnant?

If you were doing high-intensity training before pregnancy and have an uncomplicated pregnancy, you can often continue with modifications — reducing load, avoiding exercises on your back after 16 weeks, and monitoring how you feel. Avoid anything that risks impact to your abdomen. It is worth telling your instructor you are pregnant so they can suggest safe alternatives. If you are new to these activities, pregnancy is not the time to start intense exercise from scratch.

Is it safe to lift weights in pregnancy?

Yes, in general. Light-to-moderate resistance training is safe for most pregnant women who are familiar with weight training. Focus on controlled movements, avoid straining, and reduce loads as pregnancy progresses. Avoid holding your breath under load (the Valsalva manoeuvre), as this increases abdominal pressure. A pregnancy-experienced fitness trainer can advise on appropriate modifications.

This article is for informational purposes only and does not constitute medical advice. Always consult your midwife or GP for personalised guidance on exercise during your pregnancy.

Last reviewed: June 2026

Related articles: