It sounds too good to be true — and that’s because it probably is. Scientists are claiming that simply sitting on the sofa and watching a movie can burn as many calories as a 30-minute walk. The fact that the study was funded by a DVD rental firm notwithstanding, researchers at the University of Westminster found that horror films are the most effective calorie-burners. Watching a scary movie for 90 minutes causes the average viewer to burn 113 calories. It’s been the couch potato’s mantra for years — and now, there’s proof that doing nothing is actually good for you.
But I’m not convinced. For a start, 113 calories isn’t that impressive. Is it really worth putting yourself through all that palm-sweating, knee-knocking viewing for the calorific equivalent of a single slice of cheddar cheese? Then there’s the experiment itself. Participants were wired up to monitors and made to watch a selection of 10 classic horror films. That’s enough to make anyone’s heart race — and where was the obscenely large bowl of microwave popcorn? The fun-sized bag of Maltesers? In real life, scary movies do the diet plan no favours.
So what do the scientists have to say for themselves? “As the pulse quickens and blood pumps around the body faster, the body experiences a surge in adrenaline,” explains metabolism specialist Dr Richard Mackenzie. “It is this release of fast-acting adrenaline, produced during short bursts of intense stress — or in this case, fear — which is known to lower the appetite, increase the basal metabolic rate [BMR, the energy we expend while resting] and burn a higher level of calories.”
Researchers found that the infamous “Here’s Johnny” scene in the 1980 thriller The Shining made participants’ hearts race fastest, burning 184 calories, while other fat-busters included the 1975 shark epic Jaws (161 calories), 1973’s The Exorcist (158 calories) and the 1979 sci-fi film Alien (152 calories). Modern scary flicks such as the supernatural mystery Paranormal Activity and The Blair Witch Project weren’t quite as pulse-raising, causing viewers to burn just 111 and 105 calories, respectively.
But surprise, surprise, feeling frightened is not a sustainable weight-loss strategy. “You will probably compensate for it a couple of hours later by eating a big chocolate bar or heading to the pub,” explains nutritionist Melanie Brown. “It’s also not healthy — all that adrenaline goes into your muscles and it causes all sorts of problems with your blood-sugar levels. You’re more likely to give yourself a heart attack than lose any weight.”
So, if scary movies don’t help us fight the flab, in what other ways can exercise-phobes burn calories while doing, well, absolutely nothing? Around 60 per cent of our daily calories are used up by the bodily processes involved in simply staying alive: sleeping, breathing and moving our limbs. The average person burns 61 calories an hour while lying down, 68 when sitting up and an incredible 88 while reading a book or newspaper.
If you're feeling more energetic, knitting is a great calorie-buster, burning 102 an hour. Wrapping presents, and playing cards or board games for 60 minutes, uses up more than 100 calories. At work, typing and shuffling files have the same effect, while texting — as teenagers have no doubt known for years — can burn up to 132 calories if done continually for an hour. Fidgeting can account for 350 calories a day, while chatting on the phone for 10 minutes burns 22 calories.
A few years ago, Women’s Health magazine compiled a list of even more unlikely ways to burn 100 calories. Their suggestions included singing the Grease soundtrack from start to finish, lip-synching George Michael’s Faith 16 times, putting on lip gloss 765 times and swivelling around in your office chair 123 times. Drying your hair for 30 minutes also burns 100 calories, as does taking a cold shower (the low temperature causes the body to use energy by keeping warm). Laughter remains one of the best “exercises” for sofa-hoggers: just 15 minutes’ chuckling equates to 50 calories.
Claire Williamson, a nutrition scientist from the British Nutrition Foundation, warns that none of this should replace conventional exercise. “Sedentary behaviour is actually a risk factor in itself for ill health and obesity,” she says. “The amount of time spent sitting has been found to have a negative impact on metabolic risk factors such as waist circumference and cholesterol level.”
Earlier this year, scientists found that limiting the time we spend sitting to three hours a day could increase our life expectancy by two years. And doing activities standing up expends 50 more calories than doing the same thing sitting down. So, using all this new information, why not opt for a simpler way to burn calories next time you’re thinking about going for a run? Slip in a scary DVD, pick up those knitting needles and try standing in front of the television.