Naomi Watts takes Liev Schreiber for an exhausting run as she kills time between filming in Australia

Keep up, Liev! Naomi Watts takes husband Schreiber for an exhausting run as she kills time between filming in Australia

The problem with dating a Hollywood actress, is they're likely to show up in the fitness stakes.

With gruelling pressure to remain miniscule, they certainly give male co-stars run for their money.

And Liev Schreiber was no exception as he appeared to be struggling on a jog with partner Naomi Watts as they battled the Australian downpour to sweat our their toxins during an exercise regime.

Lagging behind: Liev Schreiber and Naomi Watts brave the rain in the name of fitness as they go for a jog in New South Wales, Sydney

Lagging behind: Liev Schreiber and Naomi Watts brave the rain as they go for a jog in Sydney

The Scream actor, 44, looked a little hot and bothered as he trailed behind, baring visible sweat patches on the back of his yellow vest top which was emblazoned with the slogan 'Titan Fitness'.

It seems the pair may have predicted they would run at different speeds, with both of them opting for headphones instead of chattering to each other side by side.

Naomi looked typically youthful in a pair of thigh-skimming pink shorts and a clingy baseball top.

The couple that jog together, stay together! Liev and Naomi broke into a sweat during their run in Oz

The couple that jog together, stay together! Liev and Naomi broke into a sweat during their run in Oz

The 43-year-old spiced up her gym kit with turquoise trainers that contrasted well with tanned legs.

The couple are currently in Oz, where
the King King actress lived during her teens, while Naomi is on
location for her latest project The Grandmothers.

The drama tells the tale of two childhood friends who end up falling for the other one's son.

Blonde ambition: Naomi and co-star Robin Wright shoot scenes for new film The Grandmothers

Blonde ambition: Naomi and co-star Robin Wright shoot scenes for new film The Grandmothers

Blonde ambition: Naomi and co-star Robin Wright shoot scenes for new film The Grandmothers

Naomi Watts

Naomi Watts

Twinkle toes: Naomi and Robin walked barefoot along the shore as they let the sea tickle their feet

Forrest Gump beauty Robin Wright
also stars in the film, with Coco Before Chanel director Anna Fontaine
taking her position behind the camera once again.

While Xavier Samuel, who plays Riley Biers in The Twilight Saga, and Animal Kingdom star James Frecheville take centre stage as the children.

The crew have been spied filming at Shelley Beach near Forster, before moving to the isolated Seal Rocks, with the relaxed female leads wearing summer dresses and stylish trilby sun hats.

Naomi and Liev's sons – Sasha, four, and three-year-old Sammy – are currently in Australia too.

Sunkissed: Robin and Naomi are developing olive skin during their beach filming

Sunkissed: Robin and Naomi are developing olive skin during their beach filming

Taking away the magic: Camera crew can been capturing the action on set

Taking away the magic: Camera crew can been capturing the action on set