Recent photos show Lindsay Lohan (search) looking startlingly thin.

The 18-year-old actress attributes her slimmer figure to a new exercise regimen. "I'm working out. I just got a trainer," she tells People magazine in its upcoming issue.

Pilates? Yoga?

"No, none of that stuff, though I'd like to try it sometime. Just old-school working out," said Lohan, who stars in the new movie "Herbie: Fully Loaded," which opens next month.

Her screen credits also include "Freaky Friday," "Mean Girls" and the upcoming "A Prairie Home Companion," directed by Robert Altman.

She will host the season finale of NBC's "Saturday Night Live" this weekend, with Coldplay as the musical guest.

On Tuesday, Lohan told "Access Hollywood" she doesn't pay attention to reports that she's lost too much weight, but acknowledged there is a lot of pressure in Hollywood to stay slim.

"Especially when you lose a lot of weight and then people are telling you, 'You look great!' You are like, 'So ... did I look fat before?'"