Kim Kardashian West's exercise sessions are "as built into her routine as breakfast and lunch".

Kim Kardashian West

Kim Kardashian West

The reality TV star gave birth to her and husband Kanye West's second child, Saint West, on December 5 and Kardashian family trainer Gunnar Peterson says she is determined when it comes to shedding her baby weight.

He said: "Knowing Kim, she'll be there as soon as it's safe. What I've seen of Kim over the years, it's not, 'Oh, I've got to work out' - it's as built into her routine as breakfast, shower, lunch and work.

"Kim is just on it - it's what she does."

While Christmas is nearly upon us, Gunnar doesn't think Kim - who also has two-year-old daughter North - will take much of a break from her exercise regime over the festive period.

He said: "I don't see Kim as someone who would use any excuse to buy herself extra time.

"I don't think she's going to get started based on some date on the calendar. She's not one for putting it off."

The trainer admitted the raven-haired beauty may have felt "a bit rusty" when she started out.

He added to new! magazine: "I would start with low-intensity, one-hour training sessions, because I'd want something to build on.

"The goal is for her to feel better, not worse. People who've been out of it for a long time will be a little bit rusty at first. "