According to research from the University of Westminster, watching scary movies makes for a pretty easy workout. Of course it's not the calorie-burning you'd get from a legit workout, but it's SOMETHING!
It was a small sample, and depending on the movie, more calories were burned during some than others. The selection of films included Jaws, The Shining, A Nightmare on Elm Street, The Exorcist, and The Blair Witch Project. The Shining was the movie that got hearts bumping, and calories burning, the most.
Remember though, everyone burns calories at different rates and finds different types of movies scary. Plus it doesn't exactly replace a regular 30 minute work out. But if you're like me and don't work out at all, well... it's better than nothing!