The 51-year-old star gets to slip into numerous sports suits for her role as mean-spirited gym teacher Sue Sylvester in the musical TV drama and she can't get enough of the comfort.
She said: "It's like getting into you pyjamas (wearing the tracksuits). I now probably have 30 tracksuits. The wardrobe designer likes to get a new batch every seven or eight episodes and she's crazy with the colours. I have a fuchsia one, a lime green one, they're fabulous."
Jane's character Sue is famed for her tough-talking, no nonsense nature and the actress has revealed viewers will soon find out why the cheer-leading coach has such a cold exterior.
------------------Read more: Visit our St. Patrick's Day section for more news, recipes, history and traditionsHalf of Americans unaware St. Patrick is patron saint of Ireland
In an interview with the Metro newspaper, she said: "We're going to get a piece of why she's mean in this series. We find out that Sue herself may have been a lover of musical theatre as a child. And perhaps someone badmouthed her. I don't know."
Although she is world famous because of her role, Jane insists her TV stardom doesn't impress her nine-year-old stepdaughter Haden - who she raises with her wife Lara Embry.
The actress has taken Haden to numerous glitzy events and although she is grateful she isn't dazzled by celebrity.
Jane revealed: "Kids adjust so easily. I've taken her to premieres of really big hit movies and she appreciates them. But I pick her up from school and the kids, in the beginning, were like, 'It's Sue Sylvester.' And now I'm just another mom."