World Championships: Jessica Ennis-Hill reveals return anxiety

World champion heptathlete Jessica Ennis-Hill says she underestimated how difficult it would be to return to top-class athletics after having a baby.

The Briton, 29, won gold at the World Championships on Sunday, 13 months after giving birth to son Reggie.

"Before you become a parent, you think it will be easy," she said.

"Then you're thrown into it and realise it's incredibly hard. I would be lying if I said I didn't have moments when I thought: 'What am I doing?'."

Ennis-Hill won gold at the World Championships in Berlin, Germany, in 2009, a silver two years later in Daegu, South Korea, before winning Olympic gold at London 2012.

She announced she was expecting her first child in 2014 and only returned to competitive athletics in May when she took part in the 100m hurdles at the Great City Games in Manchester.

"This time last year, I couldn't imagine stepping back on the track, let alone being at the World Championships and winning," Ennis-Hill told BBC Sport.

"I underestimated how hard it would be.

"There's always that worry and anxiety and you think: 'Am I going to be able to get back to my best?'

"We never talked about medals and I still can't believe it has happened."

"I'm really proud of what I've been able to do. I'm so glad it has all been worthwhile and I can take my shiny medal back to my son."

Her coach said Ennis-Hill had the chance to quit athletics on a high after winning Olympic gold in London but praised her ability to come back.

"No-one has done studies on coming back from pregnancy into power sports," said her coach, Toni Minichiello.

"The difficulty was we were waiting for the abdominal area to re-knit. It takes a year for a lady to come back together, depending on how the birth was. To win is a massive, massive bonus."