Science Buddies: "Ask an Expert"

I was running and my heart started beating faster. Then I thought, "When I run, my heart starts beating fast, and I loose calories. My heart also beats fast when I watch a horror movie. So, can watching a horror movie scare you enough to burn calories?" I talked to my science teacher, and she said to do some research. I researched, and what I found out is that you don't burn calories unless your muscles are moving. I told my science teacher this, and she said that the heart is a muscle, and fear can make it beat fast. So now I'm confused, does watching a horror movie make you burn calories? Or is this thought only something lazy people say to get out of excercising?

Your teacher is right that fear burns calories. An interesting topic for research is "how much?"
Does a horror movie really frighten you severely? Do you get up and run away? Probably not.
A quick web search found a few pages about fear and metabolic rate (how fast your body is consuming energy). Maybe you would like to list a number of activities such as watching a horror movie, seeing an accident, burning your finger, laughing, walking, running, lifting weights, etc. Then do a literature search to find out how much these things elevate one's metabolic rate.
I'm guessing that seeing Dracula doesn't quite measure up to running a four-minute mile

Hey, I just wanna know. Is this a testable idea? 'Cause I was thinking about using this as my science fair project. And if this is a testable idea, then how could you test this?

Since most scary situation get our adrenaline running, we often do use our muscles in ways we don't think of. Such as nervous habits, or, as you said, running from the situation. The normal response to negative stress, such as a scary situation, is the fight or flight response. This gives us an extra burst of energy, makes our heart beat faster, and hones our senses. We become like Superman. But when we're done being all tough-like, we experience fatigue, which can result from burning too many calories. There is a answer from my health class that my teacher talked about. tough guy

Hi Tarx,

You have a very interesting question, and I think you could turn it into a testable hypothesis!

While an increased heart rate may not burn as many calories as using your skeletal muscles, it will use more calories compared to when you sit and watch a movie that doesn't scare you.

To properly measure the effect on calorie use, you would have to measure something like metabolic rate, which requires expensive equipment that you will usually only find in a lab. But if you get creative, you might be able to estimate the calorie usage based on increased heart rate alone. (You would need to look in the scientific literature, where you should be able to find the metabolic rate associated with different heart rates at rest.) Then you could measure the effect of different variables (a scary movie, a funny movie, a sad movie, etc.) on people's heart rates, which would only require you to measure heart rate.

If this sounds interesting to you, let me know, and I can help you get on your way.

Heather