Britney Spears showed off her fit body - and a fierce dance routine - during her recent European mini-tour. But what did it take for the pop star to get back in shape?

"A lot of hard work," Britney Spears says.

"I have had to work hard at getting [my body] back to where it used to be," Spears tells Glamour in its January issue. "I used to be obsessed with working out ... But I can't get motivated right now because I'm so focused on my music."

What about her workout regimen?

"It isn't fun [for me], so to do it every day would be horrible," Spears say of going to the gym. "Three days a week is cool, even two. It makes me feel good and feel like I've done something. It's important to take care of your body."

Still, Spears, who will turn 27 on Tuesday, says that with her efforts comes a new appreciation for her body. "Recently I started to appreciate my body a bit more from before I had kids," the singer says. "But it completely changed."

Family Time

Spears will release her sixth album, Circus, which she describes as "really personal," on Tuesday as well - and will continue her media blitz, performing on Good Morning America. But despite her recent world travels, and whirlwind schedule, the singer says she likes being home and spending time with her sons, Preston, 3, and Jayden, 2.

"I fix breakfast for my kids when they're here," she tells Glamour. "And then we'll go for walks. During the day I spend most of the time with my children. At night is when I go to work."

With motherhood in mind, Spears passes along some tips for her sister, Jamie Lynn, who is a new mom.

"As a mother, the one thing that always goes through your head is, 'You're never enough. You never can be enough - or do enough - for your kids,'" she says. "It's a never-ending issue for me. I had to learn: Don't beat yourself up so much ... You have to take it one day at a time, do the best that you can and enjoy yourself.

"I notice that if there are some times I've been stressed ... that affects your kids," she says. "So you have to make sure you're a happy mom so they can be happy."

As for her own wishes for her family, the singer, who also spoke out about her tumultuous relationships ("I have good days and I have bad days," she says) in an MTV documentary that aired Sunday, tells Glamour she has a five-year plan.

"In five years I would like to be married and have a father figure for my kids, someone who is a provider and can be really stable," Spears says. "It's hard doing it on your own."