She's been introduced to Dr Luke and Max Martin, she now has access to most of the biggest hit-makers in the industry (Luke and Max plus all their minions), just wait until she comes out with another summer smash this year
I don't understand why Britney is a lil bit buff? Like why? Does she lowkey lift?
She has a muscular body type in general (which is also why even the slightest weight makes her look like she weighs a ton). She religiously used to go to gym and was training to be a gymnast since childhood. It's a result of these factors.