Baby bump fave: Swimming

Pregnancy doesn't mean giving up your active lifestyle. In fact, the right moves can ease common complaints like back pain and sleep troubles. One of the best exercises is swimming. It's gentle on your joints and relieves swollen ankles and you'll feel light as a beach ball no matter how big your baby bump. At least 30 minutes a day of moderate intensity activity is recommended by the NHS. Check with your GP of midwife before starting or continuing exercise in pregnancy.

Baby bump fave: Yoga

Yoga strengthens core muscles, eases back pain and helps you relax. Research shows that it may make labour shorter and more comfortable. Try an antenatal class which is gentler and focuses on relaxation - good preparation for labour. Avoid the "hot yoga," Bikram, and after your first trimester, don't lie on your back. If something doesn't feel right, check with a fitness or yoga expert.

Baby bump fave: Indoor cycling

Take a load off your legs! Cycling on a stationary bike is generally safe even if you're just starting an exercise routine. Spinning is a good way to boost your heart rate without stressing your joints. As your belly grows, you can raise the handle-bars for greater comfort.

Baby bump fave: Weight training

Light strength training can help you stay toned before and after delivery. If you were lifting weights before you got pregnant, the chances are you can continue during pregnancy as long as you go steady. Avoid heavy weights or routines that require you to lie flat on your back. If you weren't strength training before you got pregnant, find another exercise for now.

Baby bump fave: Brisk walking

Whether you're on a nature trail or a treadmill, walking is a safe way to help tone your muscles and improve your mood. It's also something most women can do right up to delivery. If you're just starting, try walking a semi-swift mile three days a week. Increase your time and speed a little each week and add hills as you get stronger.

Baby bump fave: Low-impact aerobics

Aerobics keep your heart and lungs strong, tone your body all over and give you a burst of endorphins, a feel-good brain chemical. If you are an avid exerciser, the key is to lower the intensity of your workout to suit your changing body. If you're a beginner, look for a low-impact aerobics class, like aqua aerobics, taught by a qualified instructor.

Modify: High-intensity sport

If you run or play tennis regularly, you don't need to stop - but you may want to ease up on your routine. As you get closer to your due date, run on flat, smooth surfaces to reduce impact and avoid falls. This may also be a good time to avoid racquet sports that require good balance and sudden changes in body position.

Fit tip: Abdominals

Exercises for your abs can ease an aching back and help fight a "sway-back" posture that may develop as your uterus gets heavier. Two safe options are:

• Kneeling pelvic tilt. On all fours with a flat back, tighten the abs and gently arch your back to the ceiling. Don't let your belly sag down.
• Standing pelvic tilt. Back up to a wall, with your feet three inches out. Tighten your stomach and buttocks and press your lower back to touch the wall.

Fit tip: Stretching

Static stretches target pelvic, hip and thigh muscles. They can also help lessen lower back pain. Try these:

• Static sit. Sit with your knees bent and ankles crossed. Lean forward a little, keeping your back straight.
• Static press. Sit with your knees bent and the bottoms of your feet together. Place your hands under your knees. Press your knees down against your hands and your hands up against your knees. Hold a few seconds and release.

Fit tip: Pelvic floor exercise

The beauty of pelvic floor exercises (Kegels) is that you can do them anytime, anywhere, without anyone knowing. Kegels strengthen the muscles that help hold up your uterus, bladder and bowels, which helps labour and delivery. To do them, squeeze your pelvic muscles as if you're trying to stop urinating or passing wind. Hold for five seconds and relax. Repeat 10 times, five times a day.

Fit tip: Take it easy

Too worn out to put in 30 minutes of exercise? Break it into two 15-minute sessions or three 10-minute sessions. New to exercise? Start off slowly. Begin with five or 10 minutes a day and gradually build up. Always warm up and cool down for at least five minutes. Listen to your body: if you feel hot, short of breath or tired, take a break and take it easier next time.

Should you slow the pace?

As your middle gets more crowded, your lungs and heart have to work harder. Give them a break by not overdoing it. As long as you can talk comfortably and aren't short of breath while exercising, you're moving at a good pace. Don't exert yourself to the point of heavy perspiration. If you start to feel fatigued near your due date, consider changing to simple stretching and strengthening exercises.

Don't eat for two

Exercising during pregnancy can help keep you at a good weight. Gaining too many pounds puts you at risk of longer labour and a harder delivery. But gaining too little can hurt your baby's growth. The NHS says eating for two is an old wives' tale. Energy needs don't change in the first six months of pregnancy. In the last three months, a woman’s energy needs increase by around 200 calories per day. There are no formal UK guidelines on appropriate weight gain during pregnancy, but your GP or midwife can advise you.

Move smoothly

Pregnancy puts you at risk of joint injuries, so steer clear of exercise that requires jerking, bouncing or high-impact movements. Avoid quick changes of position, such as standing up quickly, which can make you dizzy. Remember that your centre of gravity shifts as your belly grows, so it's easier to lose your balance and fall.

Caution: High temperature

When you're pregnant, your body runs a little hotter. Avoid overheating, which may increase your baby's risk of birth defects, especially during the first trimester. Don't work up a heavy sweat while exercising. Exercise less or not at all on hot or humid days. Drink plenty of fluids before, during and after workouts. And stay out of saunas and hot tubs.

Caution: Air pressure

Planning a trip to the hills? The NHS says to avoid exercising over 2,500 metres above sea level until you’ve acclimatised. Decreased oxygen at a high altitude can mean less gets to your baby. Heading to the beach on holiday? Skip scuba diving. It puts your baby at risk of decompression sickness, which may cause birth defects, miscarriage or other complications. Try snorkelling instead.

Caution: Risky sports

While exercise during pregnancy is good for you, some activities come with more risk than reward. The NHS advises avoiding contact sports where there’s a risk of being hit, such as kick-boxing, judo or squash. They can cause trauma to you or your baby. Also avoid activities that increase your risk of falling, such as outdoor cycling, roller-skating, skiing and horse riding.

Benefit: Boost your mood

Exercise lifts your spirits. It floods your body with feel-good brain chemicals like endorphins, and calming ones like dopamine and serotonin. Exercising during pregnancy may lower the risk of depression and anxiety and boost your self-esteem.

Benefit: Increase your energy

Physical activity during pregnancy gives you more energy and stamina. Strengthening your muscles and your heart can help you feel stronger and more capable of reaching your goals. Exercise also helps you sleep by relieving stress and anxiety that might otherwise keep you awake. A good night's sleep gives you more energy to face the day.

Benefit: Control gestational diabetes

The NHS estimates up to 14 women in every 100 pregnant women develop gestational diabetes. It first occurs during pregnancy and usually goes away afterwards. Hormonal changes lead to high blood sugar levels. Untreated, it can lead to serious complications for your baby. Exercise may help lower the risk of and manage gestational diabetes by lowering blood sugar levels. Talk to your GP first.

Benefit: Get ready for labour

In addition to easing aches and pains and keeping you regular, exercise also seems to prepare women's bodies for labour. Research shows that healthy pregnant women who exercise during pregnancy may have less risk of premature birth, a shorter labour, are less likely to need pain relief and recover from childbirth faster.

Benefit: Healthy baby

Regular, moderate exercise not only gives you a healthier pregnancy, it might give your baby a healthier start. Research shows that when pregnant women exercise, their developing babies have a much lower heart rate. Babies of active mums may also have a healthier birth weight.

Essential workout gear

You don't need to invest in a lot of expensive gear to stay safe and comfortable while exercising during pregnancy. The two workout must-haves are a supportive bra and trainers that are designed for the kind of exercise you're doing. Pick trainers that have good support. Other than that, just wear layered, loose clothes to stay cool.

Drink up

Don't forget that your body needs water to support the foetus and to stay hydrated, especially during exercise. So "think drink" and down about 1.2 litres (six to eight glasses) of water a day. Drink before, during and after workouts. A good rule of thumb: if you're thirsty or your urine is dark yellow, you're probably not getting enough liquids.

Know when to stop

If you experience any of the following symptoms, stop exercising and call your doctor or midwife immediately:

• Contractions
• Chest pain
• Dizziness
• Calf pain or swelling
• Less movement by the baby
• Headache
• Muscle weakness
• Fluid leaking from your vagina
• Vaginal bleeding

Stay motivated

Exercise and pregnancy both take energy. Some days you may have plenty for both and other days you may not have enough for either. It's important to listen to your body, but if you find yourself often glued to the couch, you may need some support and motivation to get moving. Try taking an antenatal exercise class, working out with a partner or even joining a group to share workout tips and advice.

Fit for two: After-baby exercise

Once your baby arrives, you may be tempted to stop exercising. Don't. Studies show that new mums who exercise feel better about themselves, adjust faster to being a mother and lose more weight. Not returning to a healthy weight can increase your risk of obesity and heart disease. Start by gradually getting back to low-impact exercise. Walking is a good place to start - and it's something you and baby can do together.

Fit for two: Abs

With baby out of your tummy, you may be tempted to whip your abs back into shape with sit-ups, but slow down. You'll be working already overtaxed, overstretched muscles. It's better to start with tummy-toners like pelvic tilts. Tighten your pelvic floor muscles as you do them to avoid further stretching. As you strengthen your core, you can gradually start doing crunches.

Fit for two: Weight loss

Don't rush weight loss! Losing no more than a couple of kilos (around four pounds) a month is better for you and baby. Eating too little can thin your bones, make it harder for your body to produce milk, dampen your mood and lead to fatigue. With exercise and a healthy diet, you'll probably be back to your normal weight within a year.

Related reading

• Exercise during pregnancy
• Get your figure back after pregnancy
• Pregnancy and gestational diabetes
• Pregnancy super foods
• Slideshow: Top surprises of life after baby arrives
• Slideshow: What not to eat when pregnant