Getting back into shape
This requires a combination of:

healthy eating habits

exercise

Starting to exercise
Specific exercises should be started immediately. While in hospital you will be invited to attend a post-natal class which is given by a Chartered Physiotherapist. You will be shown exercises that are safe to do and which are suitable for the first 6 weeks after delivery.

What sort of exercises?
Exercises will be included to:
strengthen pelvic floor muscles (bladder control)

correct posture (Important for back care and an easy way to get those muscles working)

strengthen muscles weakened by pregnancy (especially tummy muscles)
You will also be given back-care advice as looking after a baby can be hard on the back!

Swimming
It is better to wait until your 6-week check-up. This is to avoid the risk of you getting an infection.

Walking
Walking is an excellent form of exercise and can be started immediately. You can gradually walk more briskly as you feel stronger. Remember to walk tall, gently holding in your tummy and pelvic floor muscles.