Jerry O'Connell, the star of the comedy "Kangaroo Jack", has offered to help girlfriend Rebecca Romijn get back into shape for her role in "X-Men 3", which starts shooting next month.

According to Hollywood.com, O'Connell says he picked up tips from his brother who used to be a fitness trainer in Hollywood.

Romijn had raised eyebrows and concerns about her health when she suddenly gained weight. She will have to get back in shape quickly to reprise her role as the sexy all-blue Mystique character.

She says, "I've had a great year with my boyfriend. I fell in love and had lots of romantic dinners. It was worth every last chocolate mousse and bottle of wine. But now it's crunch time."