Watching scary movies can help you burn the calorific equivalent of a small chocolate bar, according to a new study by researchers at the University of Westminster.

Those who watched a 90-minute horror film were likely to burn up to 113 calories – the same sort of figure as a half-hour walk. Some movies were more effective than others, however: of the 10 films studied, the top calorie-burners were the classic Stanley Kubrick chiller The Shining (184 calories), Jaws (161 calories) and The Exorcist (158 calories).

The study found that films with regular “jump-scare” moments were most likely to help burn calories because they increased the heart rate dramatically. “Each of the 10 films tested set pulses racing, sparking an increase in the heart rate of the case studies,” said Dr Richard Mackenzie, senior lecturer and specialist in cell metabolism and physiology at the university. “As the pulse quickens and blood pumps around the body faster, the body experiences a surge in adrenaline. It is this release of fast-acting adrenaline, produced during short bursts of intense stress (or in this case, brought on by fear), which is known to lower the appetite, increase the basal metabolic rate and ultimately burn a higher level of calories.”

Scientists measured heart rate, oxygen intake and carbon dioxide output for the study, which was commissioned by the movie rental firm Lovefilm. They discovered that the number of calories used increased, on average, by a third during the screenings.

“We all know the feeling of wanting to hide behind the sofa or grab a pillow when watching scary or hair-raising scenes,” said Lovefilm editor Helen Cowley. “But this research suggests that maybe those seeking to burn some calories should keep their eyes on the screen.”

http://www.guardian.co.uk/film/2012/oct/29/horror-movies-help-burn-calories