MAFS twins Sharon and Michelle are boxing each other: 'We've been bluing since yea high'

When they're not fighting for love, they're fighting for charity!

Married At First Sight contestants Sharon and Michelle Marsh will step into the ring today for a cause.

Since the show wrapped, the identical twins have been training up to seven times a week for the white collar boxing tournament, The Royal Queensbury Championship.

And they're no strangers to a punch up!

"Shaz and I have been bluing since yea high so it's not going to be a problem," Michelle jokingly told 9 News Perth. "Her only fear is potentially getting knocked out by me in the ring!"

"We're nervous and excited," agreed Sharon.

The annual black-tie event, which is held in Perth, will see 20 boxers with no previous fighting experience jump into the ring for a crowd of 1,500 people.

"Our strengths lie in different areas," Michelle explained. "She's quicker but I've got more power in me."

Sharon also revealed her plans to reunite permanently with her partner, Nick Furphy, whom she renewed her vows with on the show.