Amanda Bynes has been recuperating at a $3,250-per-week fitness spa.

The troubled actress has been flying under the radar since leaving rehab and it has now emerged she has been staying at the exclusive Miracles Fitness Retreat in Utah in the hopes of radically overhauling her lifestyle.

The 27-year-old star was discharged from treatment for schizophrenia and bipolar disorder in December after being sectioned for her erratic behaviour, which culminated in her setting fire to a stranger's driveway in Thousand Oaks, California, and accidentally dousing her pet pooch in petrol.

Austan Torson, the owner and personal trainer at the facility, told E! News: ''She was interested in getting healthier... to get in better shape, to lose about five pounds, but mainly to strengthen up and eat healthier.''

Amanda arrived at Miracles Fitness Retreat on January 4 for the intensive seven-day Fitness Jumpstart program, where she was able to make new friends away from the limelight.

Austan said: ''I think it was a really good experience for her. She participated in everything we did. She was always up in the morning even though she was tired.''

The 'What A Girl Wants' actress was up at the crack of dawn every day for a quick snack followed by a 90-minute cardio workout with a personal trainer.

She then wolfed down a healthy breakfast before embarking on a second 90-minute workout consisting of activities like yoga and core-strengthening exercises.

After lunch, the former Nickelodeon child star would take part in a lecture about body image, counselling classes or eating disorders.

Afternoon fitness consists of a two-hour activity which varies from swimming to racquetball to Zumba, and many more.

Clients then enjoy an early dinner and some time off to relax and take advantage of the luxury spa treatments.