BODY BY ANYA: Fashion showrooms are typically pristine, rarefied places where products are carefully displayed on glossy shelves. But on Monday night, Anya Hindmarch’s Meatpacking District studio in Manhattan was transformed into a gym for a boot camp led by fashion favorite (and Equinox trainer) Lacey Stone. Among girls there to get sweaty were house model Poppy Delevingne and “Gossip Girl” star Nicole Fiscella — who, despite her tiny frame, won the push-up competition and was arguably the fastest in the multifloor stair run. The session, the second in a series, was inspired by the weekly fitness class the designer hosts at her London office. Of course, it wouldn’t be an Anya Hindmarch event if it wasn’t properly accessorized — there were Anya-branded yoga mats and tank tops reading “Anya’s Gym Class: Bags & Biceps.” After happily huffing and puffing their way through star jumps, squat holds and endless lunges, the group gathered for a nutrition session courtesy of Heather Bauer, founder of Nu-Train. Among her tips? Always leave three quarters of your plate empty and put your knife and fork down at least three times during the meal.