A fitness instructor has posted a stunning transformation on Instagram, proving to her followers that lifting weights won’t make women “manly.”

Rebecca Catherine Smith, who has more than 49,000 followers on the social media site, said she’d often “spend hours on cardio machines” in a bid to get rid of fat but “never saw results.”

She had an unhealthy relationship with food and would do cardio simply to “burn calories” rather than get fit.

But in a side-by-side comparison, Smith revealed how swapping her long runs and restrictive diet for some weights and triple the amount of food has impacted her body shape.

“It infuriates me how still so many girls think the second you pick up a dumbbell or protein shake you’ll suddenly become the hulk,” Smith wrote on Instagram next to the images. “[C]hanging my training from cardio to weights changed me completely inside & out and each to their own but I personally don’t think I’ve made my body look at all manly in my past year and a bit of weight training!”

Smith’s post, which has received more than 15,000 likes, revealed the three reasons why women need to ditch the mentality that weights result in bulking — and why they should start lifting:

1. Building strength & muscles

“Lifting builds on a woman’s natural curves and helps your body be the strongest it can. Ripped abs, sexy strong back, shoulder boulders & a curvy behind all come from lifting.”

2. Losing that extra body fat

“My body fat percent saw a massive fall when I began lifting because as your muscle mass increases your metabolism increases. Before I would spend hours on cardio machines thinking that will get rid of fat but I never saw any results. It just made me hate going to the gym and if you feel like you’re in that boat then change it up now!”

3. Healthy relationship with food & body image

“Starting weight training made me realize food is fuel and I need lots of it to get the best out of my training.”

“The amount I eat has honestly tripled since I picked up lifting and I absolutely love it … there’s no restricting and there’s no guilt in indulging in treats once in a while because what better way to fuel a sesh.”