The actress appeared in the role of Glenda Mitchell from January 2010 until March 2011, when her character left Walford after alienating almost everyone around her.
Barber told the Norwich Evening News: "That was amazing being there, being on the Square and being part of all the action. I have worked very hard in my life but I have never, ever worked as hard as I did on EastEnders.
"People don't realise but that timetable is brutal. You work every day - you are literally up between 5am and 6am every morning and because of where I live, I often didn't get home until 9pm. Then you've got 15 scenes to learn for the next day."
"The thing that's amazing about EastEnders, I think, is that the standard of the work is so high," she continued. "The people are great, but it's tough."
Barber has recently been doing theatre work and has just released her own yoga DVD, but said that she would not rule out a return to EastEnders in the future.
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Watch an EastEnders Glenda clip below: