Fit mother Jennifer Hudson

(BANG) -

Jennifer Hudson says having a caesarean section was like working out.

The singer-and-actress - who gave birth to son David, her first child with fiance David Otunga, in August - insists she was in no more pain after the operation to deliver David than she is when she goes to the gym.

She said: "Everybody told me how much it was going to hurt afterwards but I think I have a different tolerance for pain than others. By the night after I had the baby, I'm like, 'Look, I can't sit in this bed anymore. I've got to get up!'

"I've been up and about since he was born. To me, the pain is no different than when you work out a muscle you've never worked out before and it's sore."

Jennifer says her son's personality is already starting to develop, adding his favourite things are his bottle and having his diaper changed.

The 28-year-old star explained to People magazine: "He has a lot of personality, like David. He's always been a good sleeper. His favourite time to smile now is diaper changes. Or when he spits up on you - he just cracks up like he thinks it's the funniest thing. And his bottle is his pacifier. His best friend is that bottle - that's all he wants."