The former TOWIE star took part in a photoshoot for the label on Monday (24 March) and happily shared pictures of her day.
Lucy, 23, said: "At the Ellesse HQ today shooting the new range! It's amazing girls! #UKBrandAmbassador #fit&fashionable."
She also shared a snap of some of the clothes, and had her eye on a pair of yellow shorts in particular.
Lucy joked: "At Ellesse's HQ & I spy Joey Essex's @ellesseheritage yellow tennis shorts!! #Ellesse #Vintage."
Lucy has been working seriously hard to keep fit since she left TOWIE, making sure she takes regular exercise to hone her bod.
She's also overhauled her diet, and just last week posted a photo of her very healthy looking salad.
Lucy told fans: "Tuna, spinach, rocket, watercress, peppers, beetroot & lemon dressing #motivation #vegasbody #EatWell #resultswithlucy."
Meanwhile, Lucy's ex boyfriend Mario Falcone has been busy attempting to chat up Cheryl Cole. Sigh!
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