This $10 product was what really made the difference to Jennifer Lawrence's pre-X Men workouts

Jennifer Lawrence has an incredibly diverse résumé of past roles – from galactic colonist to ballerina-turned-spy, inventor of the Miracle Mop and of course, her breakout role as Katniss Everdeen in The Hunger Games. But nothing was quite as alien – nor as naked – as the blue-skinned mutant she played in X-Men: First Class.

Playing Mystique, the 27-year-old wore a skin-tight suit which basically just looked like bodypaint, meaning costumes would hide nothing. In order to do the powerful super-anti-hero justice, Jennifer felt the need to look powerful herself too. This saw her commit to some serious gym sessions, though it has been revealed that she got into top shape in just three months before filming.

Her trainer was Dalton Wong, a London-based celebrity trainer who has worked with the likes of Kit Harrington and Amanda Seyfried. And while it's safe to say he knows what he's doing, Wong actually references one special piece of gym equipment as the key to Lawrence's incredible X-Men physique. Amazingly, it can fit in your handbag and only costs about $10.

The miracle product? Resistance bands. Those long, stretchy gummy bands that come in different colours are what really helped amp up the gym sessions to target and tone particular muscles.

Wong's workouts for Lawrence included everything from yoga to weight training and running, but he told the Daily Mail that the resistance bands came in handy especially when they wanted to squeeze in mini workouts on set – even when they just had 10 minutes. They work by adding extra resistance on muscles with moves like leg lifts, squats and crab walks, engaging your muscles to make the workout more effective.

He says that they're good for people wanting to target muscles and tone up in certain spots – especially thighs and butts – and that resistance bands are good for those who are a little more apprehensive when it comes to lifting heavy weights. So if you want that booty, it might be time to invest in some resistance bands.

But to all this, Jennifer would probably roll her eyes. She's been unashamedly outspoken before about the pressures on Hollywood actresses to have a certain body image, and has put her foot down at times where she really couldn't agree with what was being asked of her.

"What are you going to do? Be hungry every single day to make other people happy? That’s just dumb," she famously said during a Q&A, justifying why she doesn't want to oblige to any strict 'Hollywood diets'.

While training for The Hunger Games, Jennifer also followed a strict workout regime. However, she was mindful of exactly how she was changing her body.

"I’m never going to starve myself for a part... I don’t want little girls to be like, ‘Oh, I want to look like Katniss, so I’m going to skip dinner'," she told Elle. "That’s something I was really conscious of during training, when you’re trying to get your body to look exactly right. I was trying to get my body to look fit and strong — not thin and underfed."

Well, it's clear that not she's not only keeping herself in top shape physically, but she's keeping things real for herself and for fans everywhere too.