Jessica Alba trained for one year -- lifting weights and taking kung fu and gymnastics classes -- to prepare for her role as Max, a genetically engineered soldier, on the Fox series "Dark Angel."
"I got obsessed with it," the 5-foot-7, size-4 actress tells Glamour magazine in its October issue.
"A lot of girls have eating disorders, and I did, too. I got too thin. . . . Now I'm concentrating on being normal."
Meanwhile, Alba is still working hard to keep fit, despite the long hours shooting the series in Vancouver, British Columbia.
"I bicycle, work out on an elliptical machine and walk uphill at a hard heart rate of almost 180 for an hour every day," the 20-year-old says.
"I do some boxing and kicking, too, but since I work for 14 hours, I can't do much more."
The second season of "Dark Angel" is scheduled to premiere Friday.