Britney Spears has a "swagger coach".
The 'Toxic' hitmaker reportedly credits her new-found confidence to a mystery expert who has helped boost her self-esteem and made her feel more empowered.
A source said: "Britney's been gradually getting better for years and being in Vegas is a big help for her state of mind.
"You can see the difference in how she was in those first shows in 2013 to now.
"But it's her new life coach - who she calls her 'swagger coach' - that's helping her take things to the next level.
"She won't tell anyone what they do or who he is, but it's working. She's more confident than she's been in forever.
"And after years of going from one boyfriend to the next, she's enjoying being single - she feels empowered and like she can do what she wants."
The 34-year-old singer has even undergone a dramatic body transformation under the guidance of the expert.
The source added to heat magazine: "She's just committing to eating clean and working out - in turn she feels proud of herself.
"She's doing yoga, sometimes twice a day and loves ballet barre workouts too.
"It's no wonder she wanted all her Vegas onstage costumes redesigned - she can't stop showing off her abs."