So many changes happen during pregnancy and childbirth, so how do we safely return to running?

It's 5am and Amy O'Halloran is lacing up her runners.

The 33-year-old is on a deadline. She has to be back to get her kids off to daycare and herself ready for work.

It's a rush and she's tired, but Amy knows her day will be better for it.

«It makes me a better mum. It makes me a better person if I just get out the door,» she said.

Amy has always been a runner; it makes her feel free.

But after pregnancy and childbirth, like so many other women, her body wasn't ready to move like it used to.

So how did she navigate getting back to running after having kids?

So you've just grown a tiny human (bravo!) and naturally your body has transformed to accommodate it. Then there's the birth.

After weeks of being holed up in the newborn bubble, you might think you've recovered.

According to Arna Opperman, physiotherapist and director of Bump Physio and Co, even if you feel like you're ready to get back out there, you may not be.

«A new mum may have no issues affecting her daily life, this doesn't mean she is ready to return to running,» she said.

Opperman focuses on helping women in the pre- and post-natal period, and says you shouldn't be going for a run within three months of giving birth.

When it comes to physical health, the two big ones to look for are pelvic floor strength and abdominal separation (rectus diastasis).

And a warning …

«Failing to address issues in the post-partum period is likely to have an effect if not in the short-term, most definitely in the future,» she said.

Amy had Henry (3) and Jemima (1) within 19 months of each other.

She experienced pelvic floor issues and abdominal separation with both.

She now runs about 100 kilometres every week, but it took a fair bit of conditioning.

The pelvic floor is a combination of muscles