Gold in Beijing? Jessica Ennis couldn't have done it without Reggie's grandparents

How on earth did she do it? Well, the 30-year-old says she owes a lot to her own mum…

"It wasn't easy to go back into training – I couldn't have done it without my mum and dad and Andy's parents," she told MFM. "I've got a great support network from the family and Reggie loves spending time with his grandparents."

Jess waited 4 months before returning to the gym after giving birth and then started doing "a bit of exercise a few times a week, reminding my body what it used to do".

She started things off on her exercise bike and then slowly started running again.

"It had to be really gradual," she says, which is true for any new mum starting an exercise regime.

But despite trying to take it easy, Jess admits she was "always comparing myself to 2012 and how I was training then".

She added: "I had to accept I'm a completely different athlete. My coach keeps saying: 'These are your post pregnancy PBs, don't look at your old PBs.'"

And while her Personal Bests might be different, Jess is still hoping to defend her heptathlon crown – at this summer's Olympics in Rio.

Preparing for Rio

Now Jess has a son, she can't spend the long hours in the gym she used to. Instead she's adapted her training schedule to suit her toddler – focusing on quality rather than quantity – and training in the morning and evening so she can spend afternoons with Reggie.

"I always get Reggie up and give him breakfast," Jess says.

Then she goes to the track for technical exercises and running before returning home.

"I train at home in the garage on the bike when Reggie's gone to bed," she says.

"Making sure your baby has everything he or she needs becomes your first priority."

But some days Reggie will join Jess at the track.

"If I'm doing the javelin, he can come down with my mum," she says. "The track's huge so he can run around and play football and I can see him on the other side of the track.

"I'm quite lucky, there's a lot of flexibility."

But switching back to athlete-mode can be difficult. "I never struggle switching back to being mum when I get home, but sometimes I'll get to training and be thinking: 'Has he got everything? Has he got his lunch?'"

Being away from home

When her son was just 13 months old, Jess left Reggie at home in Sheffield with his dad and her mum so she could take part in the World Championships in China's capital.

"Leaving him behind was the hardest thing I've done, having to be that far away from home," she admits. "Even though he won't remember it, it was hard for me."

But the new mum made sure she stayed in touch. "We FaceTimed every day," she says.

So will Reggie travel with Jess to the Rio Olympics? She hasn't decided just yet. "He's a bit older now so we're going to see how the next few months go and then take a decision from there," she says.

But even if he did join his mum in Brazil, Jess would need a few days away to compete. "At the Olympics, I wouldn't see him the 2 days I compete – they're really long, busy days," she says. "I need to stay focused and be in the zone."

So does Jess think she can take the gold?

"I'd like to get close to where I was before but it has been a challenge to get back to my best," she admits. "I've always got that competitive edge to be the best I can be – it's still there, I just kind of have a different perspective now."

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Jessica is supporting P&G’s nappy brand Pampers ‘Little Champions campaign’ inviting parents to celebrate their babies champion moves as well as being an ambassador along with her own mum Alison Powell for P&G’s Thank You Mum campaign that celebrates a mother’s strength in helping her child to achieve their dreams. Watch the video below.