After Rebel Wilson declared 2020 her “year of health”, fans were watching and waiting to see if the star stuck to her plans.

She has since been hitting the gym with some very intense workouts, thanks to her fitness instructor Jono Castano Acero.

He took to Instagram to show off just how hard Wilson has been working, as she smashed out a core and upper body workout using a medicine ball.

“That’s it, as hard as you can,” the celebrity trainer can be heard saying in the background before counting down from seven to one.

Captioning the post, Castano Acero wrote: “The ball didn’t stand a CHANCE! Work it gurl @rebelwilson.”

Fans were quick to commend Wilson for her hard work, saying that she was “killing it”.

“That ball didn’t stand a chance,” another said.

Wilson first made the claim that 2020 was her year of health after overindulging in the holiday season.

“Okay so for me 2020 is going to be called ‘The Year of Health’ — so I put on the athleisure and went out for a walk, deliberately hydrating on the couch right now and trying to avoid the sugar and junk food which is going to be hard after the holidays I’ve just had,” she shared in an Instagram post.

“But I’m going to do it! Who’s with me in making some positive changes this year?”

Fans rallied behind the star, saying that she’s already looking great.

“I’m so proud of you! You look fantastic already with your weight loss,” one said.

“You look great, you look absolutely beautiful beforehand and still now. Such a role model,” another wrote.

“You already look amazing! Killing it! Any positive changes are good changes,” another fan said.

In an interview with E!, her trainer explained that he had created a specific program for Wilson that covered six days.

Over the six days, the workouts cover High Intensity Interval Training (HIIT), mobility, weights and resistance as well as a rest period.

Although he said that there haven’t been any challenging moments, he said it’s been an “absolute pleasure” working with Rebel as she is a “role model with great humour”.