How a High School Musical 2 Star Lost 30 Lbs.

Landing the part of Martha Cox, the "pop-and-lock" girl in High School Musical, gave KayCee Stroh, 23, a big boost in confidence. But the life-long dancer had recently gained 40 lbs. after a blood clot in her calf forced her to spend three months in bed. Now, Stroh is back on her feet, 30 lbs. lighter and telling PEOPLE how she did it.