Speaking to E! News, Anna – who's been training the singer for more than a decade – spilled:
"Every day is different because I want to make sure I'm preparing her not just for the Super Bowl, but for each day as it comes. For instance, yesterday she had a really long dance rehearsal in the afternoon, so we just focused on an hour of pure strength in the morning."
Whether she's working up a serious sweat with dance interval workouts smashing out some quick HIIT or circuit classes, the 42-year-old gets in a session almost every day of the week, shares Anna.
"Her commitment is six days a week. She has Sundays off."
And it's not just her workout plan that's had an overhaul ahead of the February 2020 Super Bowl show – the mum-of-one has had a diet shake-up, too, with her current focus on eating 'clean'.
"Little to no sugar, no dairy, balanced meals with lots of fresh vegetables and fish," Anna explained.
"Right now, we're focused on little to no sugar and being pretty strict about that. She's good about it in general, but she will treat herself. Balance is really important. Having those moments where you're allowed to cheat every once in a while is also very important."
So, what does the superstar eat in a regular day?
(And, more importantly, is it achievable for us mere mortals?)
"Breakfast could be eggs or avocado with olive oil, tomato, sea salt, then a smoothie, berries, plant protein, sometimes greens or green powder," Anna told E!.
"Then for lunch, we have fish and fresh vegetables or a salad with lots of colours."
Afternoon tea is vegie soup – leek and eggplant, carrot and ginger, and artichoke all make the menu – with a side of cucumbers with lemon and salt, followed by fish and vegies for dinner.
"It's usually cold for lunch and warm for dinner."
And as for those treats Anna mentioned?
"Pork chops. Pork chops are my least favourite food [laughs], but she likes them. Sometimes there will be dark chocolate, like a really pure dark chocolate with little to no sugar in it."
She fronted Spanish court in June 2019 to "help clarify the facts over her tax situation in Spain", read a statement released at the time, but had "paid the full amount, as well as providing the tax office with exhaustive information" as soon as she learnt how much she owed Spanish authorities.