Star fitness: And the best workout award goes to...

Tonight some of the planet’s most physically perfect specimens will book a babysitter and pull on their Spanx in the hope the movie gods might see fit to bestow on them a small golden man to stand in their guest toilet.

But while those involved would like us to think Oscars night is all about the work, darling, we know it’s really about frocks ... and the physiques.

Anne Hathaway is said to have lost nearly two stones to play Fantine in Les Miserables, for which she is nominated for Best Actress in a Supporting Role. But when she’s not nibbling on lettuce (she refused to reveal details of her diet, lest foolish young things try and copy her), she maintains the condition of those coltish legs on the ski slopes. She was spotted recently in Switzerland with the designer Valentino.

She’s not the only celebrity fan of the snow – the Jolie-Pitts are quite the healthy ski family and Jessica Biel has been snowboarding since she was old enough to pull on a beanie. But surely it’s about modelling your new Chanel skis and leather salopettes? How many calories can a person realistically expect to burn while skiing?

“A lot,” says Dave Leith, lead strength and conditioning coach for snowsports at the SportScotland Institute of Sport. “There’s research that shows an 11 stone adult can burn 422 calories an hour recreationally skiing at a moderate speed. Cross-country skiers burn more calories than downhill skiers – about 500 an hour, while a snowboarder can burn between 250 and 630.”

It’s the perfect exercise to develop shapely legs, he says, working the quadriceps, glutes, hip flexors and hamstrings. “Maintaining effective posture also means the muscles supporting the shoulder will be challenged,” adds Leith, “as will torso musculature – erector spinae, abdominals and stabilising muscles.”

In brief, if you’re doing it properly, every muscle in the body gets an effective workout. I’m still not convinced. You’re just sitting on a chair going up a hill, then sliding down again. It’s hardly the height of physical exertion.

“You’ve heard of high-intensity  interval training?” Leith hits back. “This is basically short bouts of  exercise followed by a rest period,  repeated. Skiing is the same thing. This means we can keep technical quality high and intensity high. It’s also not as boring.”

But when there’s no snow – and your non-Hollywood budget doesn’t stretch to a month in Aspen – you can still get the same results in the gym.

“Any circuit training, high-intensity interval training sessions or spin  cycling are excellent ways of training, especially for those with restricted time,” says Leith.

“And there are many facilities in the country where year-round skiing tuition is available. Places with real snow like Snow Factor in Braehead. Just make sure you seek professional advice and that the exercise selection, loading and repetitions are appropriate for your current level of fitness. Perfect technique is essential.”

NAOMI WATTS

Nominee: Best Actress, The Impossible

Sport: Yoga, pilates, running, cycling

The 42-year-old mother of two is often seen cycling or jogging around New York with her actor partner Liev Schreiber, and she favours exercise over diet. “If I try to put myself on diets I end up breaking them and craving foods I wouldn’t normally eat,” she says. “If someone told me I had to cut out carbs I would be very upset. I love bread and pizza. And I have a sweet tooth as well. It’s about moderation.”

BRADLEY COOPER

Nominee: Best Actor, Silver Linings Playbook

Sport: Gym

Buff Bradley swears by the gym for getting him in shape – plus pinning “a picture on the fridge of how you want your body to look. It’s a constant reminder where you need it most”.

JENNIFER LAWRENCE

Nominee: Best Actress, Silver Linings Playbook

Sport: Yoga, pilates

With a goal “to look fit and strong – not thin and underfed”, Lawrence has a refreshingly grown-up attitude towards her body. Her pre-Baftas regime consisted of Epsom salts baths, non-bloating foods and yoga/pilates-style exercises based on stretching rather than sweating. Having said that, the 22-year-old says she “loves exercising” so is at a distinct advantage when it comes to staying in shape.

HUGH JACKMAN

Nominee: Best Actor, Les Miserables

You wouldn’t know it to look at him now, but the Honourable Huge was once known as ‘chicken legs’ at his gym in Australia. Now his personal trainer says the 44-year-old is looking more ripped than ever, thanks to 90-minute early-morning sessions in the gym – sometimes as early as 4am. He starts with a warm-up and cardio session, followed by weights – squats, deadlifts, presses – then finishing with more cardio. All followed up by at least seven hours’ sleep a night.

JESSICA CHASTAIN

Nominee: Best Actress, Zero Dark Thirty

Sport: Yoga

As a strict vegan and yoga fanatic, Chastain has described gaining weight for her role in The Help as “a form of torture”. Happily for her she loses weight quickly – perhaps partly down to those daily 5:30am gym sessions. “I’m not going to be the girl with the private yoga instructor at my house,” she says. “I don’t want anyone to think, ‘Oh, she’s famous, she’s different than me.’”

Twitter: @Ruth_Lesley