Rosamund Pike has almost regained her six-pack abs.

The 'Gone Girl' actress, who gave birth to her second son, Atom, in early December, got ''back into her pre-baby clothes'' in the past five weeks by working out for an hour, five days a week.

The 35-year-old star's personal trainer Holly Lawson said: ''She was so fit for 'Gone Girl'. She had never been that fit in her life. She really wanted to get back in that space again after having the baby. When she was at the [Golden] Globes we hadn't started working yet, but she had started doing things we did [during filming]. From the Globes to now is all the work that we put in. She is amazing. Her body is literally back to what it was...she is close to a six-pack again.''

The blonde beauty, who also has a two-year-old son, Solo, with her long-term partner Robie Uniacke, was eager to look her best at the Oscars, but plans to now reduce her intensive exercise routine, which includes running, burpees, squat jumps and planks, to two or three times a week.

Holly told E! News: ''She's back into her pre-baby clothes. I don't go off of weight unless it's required because I think it can make women, particularly actors, obsessive over something that is not the most important. Everything I do and preach is about being the best version of you. Being the strongest, smartest, most loving version of yourself.''