There are two things I find particularly of note after watching Gone Girl: 1) it’s undeniably a brilliant film, 2) Rosamund Pike’s body in the bedroom scene towards the end is quite remarkable – she looks lean, toned, feminine yet strong. 

After some frantic investigating on my iPhone walking out of the cinema, I discovered that welterweight boxer Holly ‘Lil’ Bear’ Lawson (@lilbearlawson) trained Pike for the role. Why a boxer? ‘She gained and lost more than 14 pounds, 3 times over the period of a few months, as to realistically look like the character over a period of time,’ Lawson told ELLE and professional boxers have to lean out for fights so they’re used to fluctuating weight for their profession.

‘Rosamund worked REALLY hard for this role. [Alongside the boxing] I had her lifting heavy weight to build muscle, and then doing a lot of high intensity, plyometric work to lean out. That coupled with a LOT of running’.

Boxing isn’t a natural choice for most women (the face!) but Lawson dispels that common myth, ‘you don't have to hit anyone else or be hit. Just go try it, there's no harm in trying something new, and you'll probably find that there's some part of it you enjoy’.

Look out for all-women classes or boxing circuits, suggests Lawson, ‘If you're looking for a group dynamic and feed off that energy, search online for a popular group class’. But if it’s ‘proper technique’ you want to master, bite the bullet and head to ‘a real boxing gym’.

It takes dedication to see a change like Pike’s, ‘you need consistency. I recommend my clients workout 5 days a week, with the workload being different day-to-day as to not burn out’. As for nutrition Lawson has clients who are super strict and others who aren’t, ‘Have it be something you can live with. Realistic goals ALWAYS work better than diets’.

Still not sure boxing is for you? ‘I believe boxing is one of the purest sports. It's all about YOUR discipline, YOUR ability to mentally make yourself do something that is the opposite of human nature (to stand and fight instead of fleeing adversity),’ says Lawson. ‘I see it as being a massively empowering thing for any woman to participate in.’

Tried it, love it? The kit you need:
- a pair of gloves and hand wraps
- flat soled athletic shoes
- comfortble workout attire you can move in