An Instagram star known for her jaw-dropping workouts has posted a clip with her mum.

Jen Selter shares her workout programs, fitness tips and recipes to her 12.6 million followers on Instagram.

When she's not training on her own, she's usually taking videos of her workouts with her sister Steph.

And if it's not her sibling, it's her mum.

The fitness babe recently posted a clip on her social media of her matching outfits with her mum.

But it's no surprise that people thought they looked like twins.

Have you ever been mistaken for someone else? Share your stories with us below...

The fitness queen was seen on her mum's back
The fitness queen was seen on her mum's back

She wrote: "Outfit switch.

"Teaching my mum the IG ropes part 4... How did she do this time?"

In the video, Jen starts by swinging her arms in the air with her mum copying her.

Then as the duo jump, their outfits switch as the beat of the song drops.

Jen and her mum were wearing matching outfits
Jen and her mum were wearing matching outfits

After a hi-5, Jen, who is wearing green, can be seen on her mum's back as she lifts her up and down.

Since she posted the clip earlier this week, it garnered 72,300 likes.

One said: "So cute!"

Another added: "But who's the mum? Twins."

Jen has over 12 million followers on Instagram
Jen has over 12 million followers on Instagram

A third commented: "100% good."

And a fourth wrote: "I need this outfit."

Meanwhile, this isn't the first time Jen's mum was mistaken for her sister.

The video shows the duo demonstrating a little home workout which targets the abs, legs and glutes.

Her inspiring caption read at the time: "A little home workout with my @mamaselter. Tag someone you want to do these moves with.

"Here are some daily reminders for those who need is since mercury is back in retro. You are not your past.

"Breathe when you are feeling stressed. Don’t let negative thoughts control you. Do something that makes you smile.

"Strive for progress, not perfections. It's okay to not be okay."