Whether you have always exercised or are only just starting now, exercising in pregnancy can be extremely beneficial. It may not be the time to run a marathon or start rock climbing, but if you're otherwise fit and healthy, don’t assume you’re restricted to just a walk around the block.

The benefits of exercise during pregnancy include:

1. Keep pregnancy niggles, such as backache and pelvic girdle pain, constipation and fatigue, at bay.
2. Feel better about the changes that are happening to your pregnant body.
3. Maintain a healthy weight.
4. Get a better night's sleep.
5. Help to reduce or prevent depression and improve your self-esteem.
6. Prepare your body and mind for the demands of labour and birth.
7. Get back into shape after your baby is born.

(Baby Centre UK)

Top Tips

1. Get the a-ok from your doctor that you can exercise as some problems in pregnancy may stop you from doing so.  If you’ve been exercising for a long time you’ll probably be fine and will just need to adapt what you're doing.  If you’re new to exercise you may need to take things slow to start with.  It’s always better to err on the safe side.

2. If you’re new to exercise, start slow!  You can alway gradually increase intensity or length over time but remember to listen to your body.  Some women like to wait until their second trimester when the sickness and tiredness has improved.

3. As your pregnancy progresses and your baby grows, you will have to slow down a little!  Don’t be surprised when you have a little less pep in your step at your zumba class or you aren’t quite making the miles you used to on your run.  You should still have enough breath to be able to hold a conversation.  If you exercise for half an hour, try and rest for half an hour afterwards.  Maybe try relaxing with my pregnancy friendly stretches.

4. Always tell instructors that you are pregnant, whether you’ve been going to a class for a long time or are new.

5. Drink plenty of water before during and after exercise.  Dehydration can restrict the blood flow to the placenta and overheating can bring on contractions.  Keep an eye on your wee to make sure it stays nice and pale.  If it goes dark, don’t panic, just drink a glass of water an hour until it lightens.

6. Avoid sports with a high risk of falling and if I really have to say it - avoid contact sports…  It’s ok to go to Zumba if you have two left feet, as long as you can stay standing on them.
   Also avoid exercising in hot weather and if you find yourself on the top of a mountain where the air is thin, take it easy.

7. After your first trimester don’t lay on your back for long periods of time.  The weight of your bump can restrict blood flow and make you feel faint.

8. Eat well.  The amount you need to gain will differ depending on your pre pregnancy weight.  Exercising will burn more calories. Your doctor will keep an eye on your weight throughout your pregnancy and will help you if you are under or over weight.

9. Dress comfortably.  This will probably mean going shopping (oh no!)  Make sure your maternity bra is very supportive and wear loose clothing with layers you can remove when you get hot.
   If your feet have grown or swollen during your pregnancy, don’t cram them into your old trainers.  Get down to the shops and treat yourself to a new pair.

10. Avoid any exercises that have you standing still for too long like lifting weights and some yoga poses.  Standing still for too long and reduce blood pressure and make you dizzy.  Break up these exercises by having a short walk.

11. You may not have any other choice - but get up slowly!  Your centre of gravity will shift as your bump grows and if you get up too fast you may find yourself swiftly back down on the floor.

12. Make it a habit.  The more regularly you exercise, the easier it will become.  Try for at least 30 minutes of exercise 3 times a week.

13. Do a combination of aerobic exercise and stretching every week.  This way you are preparing your body in every way possible and not repeating too much of one thing.

14. Listen to your body and stop exercising if you're in any pain, feel faint or short of breath, have any fluid loss, start contractions or if your babies movement decreases dramatically.  If any of these things persist, contact your doctor. 

References:

https://www.nhs.uk/conditions/pregnancy-and-baby/pregnancy-exercise/?
https://www.babycenter.com/0_the-13-rules-of-safe-pregnancy-exercise_622.bc
https://www.babycentre.co.uk/a758/guide-to-exercising-in-pregnancy
https://www.nct.org.uk/pregnancy/exercise-during-pregnancy