Olivia Wilde's face turns a ''holy-f**k-magenta'' colour when she exercises.

The 32-year-old actress - who has two-month-old daughter Daisy and two-year-old son Otis with her partner Jason Sudeikis - believes her face turns a shockingly bright shade of pink and she resembles a ''tomato with a human torso'' when she gets her ''a*s kicked'' in a work out.

The star took to social media to ''document'' her change in complexion, which saw her post a picture of her following her fitness session.

She captioned the upload, which she shared to her Instagram account: ''Nothing cooler than a conspicuous locker room selfie but I needed to document the exact shade of holy-fuck-magenta my face turns after getting my ass kicked at @tracyandersonmethod. I'm like a tomato with a human torso that is slowly but surely recovering from popping out a ten pound kiwi. (sic).''

And the golden haired beauty - who has been dating the 41-year-old actor since 2011 - has taken to social media to gush about her beau.

Alongside a black and white picture of the couple at the White House, Olivia admitted she has spent ''eight incredible years'' with the 'We're The Millers' star.

She wrote: ''Stumbling out of the White House at 4am after an incredible night celebrating 8 incredible years. (sic).''

Meanwhile, the 'Vinyl' star was close to giving birth to her second child in a tunnel as her and Jason were stuck in a traffic jam en route to a Beyoncé concert in November last year, although it turned out to be a false alarm.

Speaking about the moment, Jason recalled: ''We came really close. Daisy was born on Tuesday, but on Friday night, [Olivia] and I were going out - date night.

''So, we were in line to get in the Lincoln Tunnel and there was an accident in there. Everything was gummed up, so it was going to take us like an hour to get through the tunnel.

''I don't know if it was the pressure, if it was the traffic, or the fact that we were going to be late. It was just bad in the back seat of the car. We U-turned and got it out of there. We figured it would be a bad scene to have the baby in a tunnel - and a little redundant!''