Beyoncé Knowles has to work hard at her marriage.

The 'Crazy in Love' singer - who married rapper Jay-Z in a secret ceremony last April - admits relationships aren't easy and require dedication, like everything else in life.

She said: "Everything that's worth anything you have to fight for. You have to fight in your relationships, I have to fight for my career, I have to fight to stay in shape, because I get tempted to eat good old chocolate, and all this stuff everybody loves.
It's all a fight, but it's worth it."

Beyonce also revealed she is starting to feel old as she doesn't understand the latest social networking phenomenon, Twitter.

The 27-year-old beauty said: "My sister Solange is the Twitter queen. She told me about the twittering, but I don't get it, I feel like I'm getting really old. I'm like, what? I don't understand. Just call me."