But if you haven't got your own personal trainer - which sadly, I don't - can a class really help you to get a body like hers? I pulled on my trackie bottoms to find out.
Promising to get you in better shape in 10 sessions, Beautcamp Pilates is a more intense version, using Allegro Reformers for the strength, core and flexibility exercises, although the beginner sessions are still suitable if you've never tried a Pilates class before.
The high-tech reformers actually look pretty low-tech - long padded black benches, with various coloured springs to hook and unhook, which regulate the resistance, plus a pole, mat and box to assist with the different positions.
In fact, that's true for most of the class. The 55 minute cardio workout seems simple, and if you've done yoga you'll recognise similarities in some of the moves, but hidden beneath some straightforward repetitions of small movements lurks a fat-burning, muscle-toning complete body overhaul.
One example involved crouching in a squat position while sliding one foot out to the side. Sounds easy but by the umpteenth repetition, my muscles were trembling. Others meant tensing your stomach muscles until they were all but on the verge of collapse.
It's not just fat burning either, Pilates' small movements are great for improving posture and alignment, as well as making your muscles stronger and more flexible.
Despite its 'bootcamp' name, our instructor was endlessly patient, full of praise and ready to make any tiny tweaks if anyone wasn't in the right position - no sergeant major screaming here. However, his apparent absence of body fat and incredibly defined muscles just go to show that the workout will hone you more than you thought possible.
And while one session won't turn you into Jennifer Aniston overnight, the next morning there was no doubt my entire body had had a thorough workout. No surprise that this is the kind of bootcamp the stars prefer!
Visit www.beautcamppilates.co.uk for more information or to book a class.