She's begun a serious exercise regimen and gotten on a pretty intense diet.
A source said:
"Britney has been on an extreme diet and exercise regime. She has been cutting out carbs and replacing meals with juice drinks. She was doing several hours of exercise a day before the launch and is trying to stick with the regime."
We're really glad she's exercising more often, that's always a good thing, but we're not sure about the crazy dieting.
Replacing meals with juice drinks is only good if the juice is a good balance of nutrients.
Though we're sure she knows what she's doing and will probably be looking in top shape within a few weeks!
[Image via Arnold Wells/WENN.]