Millie, 24, has shared a snap of herself doing some squats with her personal trainer, and it was clearly a killer session.
She added: "Literally seeing double after leg session with Rich Tidmarsh."
That does not sound fun to us, Millie!
The health conscious former Made In Chelsea star, who married Professor Green in September, has also been keeping an eye on her diet.
She ate out for breakfast on Tuesday, and opted for a very healthy looking poached egg, spinach and halloumi fried breakfast at The Modern Pantry in London. Yum!
She also drank a matcha latte. Matcha is a concentrated green tea powder which is said to boost energy.
We love a superfood, though we're not sure if we'll be rushing out for a green latte just yet!
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