Which activities suit each stage of pregnancy

Which activities suit the first, second and third trimesters?

The same gentle, low-impact activities suit all three trimesters, so you usually don't need a different routine for each one. Good choices include walking, swimming, stationary cycling, low-impact aerobics, light weights or body-weight exercises, and gentle stretching or yoga⁴. If you swim, skip breaststroke; exercising in water is also fine⁵. Everyday movement counts too: gardening, walking to the shops and breaking up long spells of sitting⁶.

Aim for a moderate effort, where you can talk but not sing⁷. During pregnancy, and after birth once ready, women with no medical reason not to should aim for at least 150 minutes of moderate aerobic activity a week, with a variety of aerobic and muscle-strengthening activities; gentle stretching may also help. Women who were regularly active, including at vigorous intensity, before pregnancy can carry on³. After giving birth it's normal and right to take a break, especially in the first weeks: rest, recovery and adjusting to life with a new baby matter too, and activity can build up gradually from there.

You don't have to reach that amount straight away. Activity of any length counts. If you weren't active before pregnancy, start with small amounts and slowly build up how often and how long you exercise⁴. If you're brand new to exercise, ask your midwife or doctor when to begin; advice on whether to start in the first trimester isn't settled⁴. As your pregnancy goes on, be ready to swap harder activities for easier ones.

Which activities should you avoid while pregnant?

Avoid sports where you could be hit in the belly, and activities where you could fall or lose your balance. The aim is to adapt, not to stop. Martial arts, football, rugby, tennis and squash are on the list, along with horse riding, skiing and gymnastics². Basketball is too⁸. After 20 weeks, also avoid netball and activities that limit your oxygen, such as free diving, scuba diving and mountain climbing¹. Scuba diving isn't considered safe because the baby has no protection against decompression sickness and gas bubbles in the bloodstream².

Balance changes after the first trimester, and pregnant women are 2–3 times more likely to be injured by falling than women who aren't pregnant⁹. Take extra care on uneven or slippery ground.

Avoid lying flat on your back after the first trimester (12 weeks), because it can cause problems with blood flow. Prop yourself up with a pillow instead⁸. Staying motionless, including standing still, may also lower blood pressure in 10–20% of pregnant women⁹.

Strenuous exercise in hot, humid weather could push your body temperature higher⁹. Keep activity gentle in that weather, or move it indoors.

Swap contact or fall-risk sports for swimming, walking or stationary cycling.

Can you keep running or lifting weights while pregnant?

Often yes, if you did it before pregnancy and have no medical complications. Women who were active before pregnancy can usually continue, including those who did vigorous activity³. Running is fine if you're experienced; if you're new to running, it's not a good time to start². If you're used to lifting weights, it's safe to continue⁸. A physio or trainer who understands pregnancy can help you plan a programme¹.

Keep your effort moderate. High-intensity exercise and extreme sports can put you and your baby at risk¹⁰. Perceived effort may understate how hard your heart is working in pregnancy, so if you're very active, check your plan with your midwife or doctor rather than relying only on how hard it feels⁹.

Heavy lifting is the main thing to be careful with. Straining with a held breath raises blood pressure and pressure in the abdomen, and may briefly reduce blood flow to the baby. Large rises in abdominal pressure may also harm pelvic floor support, which may raise the risk of leaking urine or stool, or of pelvic organ prolapse, during or after pregnancy⁹. Keep breathing steadily when you lift. Resistance bands or body-weight moves such as squats and lunges are other ways to stay strong⁸.

No firm limit on weight, distance or pace is clear yet, so personal advice matters.

When to check with a health professional

If you're starting exercise after a long break, it's always a good idea to see your doctor first. Your midwife or doctor can tailor advice to you, especially if you're new to exercise. For an injury or a health condition, see a health professional, such as your doctor or a physio.

Getting out of breath when you exercise is normal. Breathlessness that's much worse than the effort explains, or comes with chest pain, is not.

Call your local emergency number for chest pain or pressure (or pain spreading to the arm, neck, jaw or back, especially with sweating or feeling sick), severe breathlessness, fainting or collapse, signs of a stroke, a serious injury, or someone who isn't safe. In pregnancy, add heavy bleeding to that list.

These signs need your midwife, doctor or maternity unit straight away, even when they seem mild: bleeding from the vagina, fluid leaking, regular painful contractions, the baby moving less than usual, pain or swelling in a calf, a bad headache or changes in vision. Stop exercising and call them.

If you feel dizzy, breathless, unwell or too hot, or have unexplained discomfort, stop. If it doesn't settle, get medical help; if it was mild and passed, see your doctor or midwife. For a sore muscle or joint, or soreness a day or two later, ease off, and get advice if it persists. Pain during exercise is a signal to stop or ease off. Unusual tiredness isn't something to push through: get it checked by a doctor.