Safe Exercise in Pregnancy: A Trimester-by-Trimester Guide

For a healthy pregnancy without complications, staying active is one of the most evidence-backed things you can do. Regular moderate exercise lowers the risk of gestational diabetes and pre-eclampsia, helps manage weight gain, eases back pain, improves mood and sleep, and is linked to smoother labours and faster recovery. It does not increase the risk of miscarriage or premature birth in uncomplicated pregnancies.

• Walking — accessible, low-impact and easy to scale up or down.
• Swimming and aqua-aerobics — the water supports your weight and eases joint and back strain.
• Stationary cycling — keeps intensity up without the fall risk of a road bike.
• Prenatal yoga and Pilates — build strength, flexibility and breathing; choose pregnancy-specific classes.
• Modified strength training — light-to-moderate weights with good form; avoid heavy maximal lifts and breath-holding (the Valsalva manoeuvre).
• Pelvic-floor and gentle core work — daily.

• Contact sports (football, martial arts, boxing) — risk of impact to the bump.
• Activities with a high fall risk: skiing, horse riding, gymnastics, mountain biking.
• Scuba diving — the baby can't tolerate the pressure changes.
• Hot yoga / hot Pilates and exercising in very hot, humid conditions — overheating risk.
• Lying flat on your back for long periods after the first trimester — it can reduce blood flow; tilt or prop yourself instead.
• Heavy maximal lifting with breath-holding, and any exercise at high altitude you're not used to.

First trimester

Keep doing what you did before if it feels okay — just dial back intensity if nausea and fatigue hit. Stay cool and very well hydrated. There's no need to stop running or lifting if you did so before and feel well, but this is not the time to start a brand-new high-intensity programme.

Second trimester

Often the best window. Swap any back-lying exercises for inclined or side positions. As your bump grows, your centre of gravity shifts — favour stable, low-fall-risk activities. Strength and mobility work pays off now.

Third trimester

Reduce intensity and impact; swimming and walking come into their own. Loosening ligaments (from the hormone relaxin) mean joints are more mobile, so avoid deep stretches and sudden direction changes. Keep up pelvic-floor work and gentle movement right up to birth if you feel well.

Your pelvic floor supports your growing uterus, bladder and bowel, and takes real strain in pregnancy and birth. Daily pelvic-floor exercises reduce the risk of leaking urine in pregnancy and speed recovery afterwards.

• Squeeze the muscles you'd use to stop a wee, hold for a few seconds, then release fully. Repeat 8-10 times, several times a day.
• Mix short, quick squeezes with longer holds.
• For the core, focus on gentle deep-abdominal and breathing work; avoid heavy crunches and sit-ups, which can worsen tummy-muscle separation (diastasis recti).

Mild breathlessness during exertion is normal, but you should always be able to pass the talk test. If you can't speak in full sentences, ease off. Stop if anything feels wrong — your instinct matters.