Since Valentine's Day is this week, I thought I should do an experiment that had to do with your heart. Luckily, a list member recently sent me just the thing. It is an easy way to watch your heart beat. You will need:

- a dark room
- a flashlight
- a place to lay down flat on your back
- a lighted clock which shows seconds

First, dim the lights. The room does not have to be totally dark, but you want it dim enough so that you can easily see the beam of the flashlight on the wall. Lie on your back with your feet pointing towards a wall. Turn on the flashlight and place it on your chest, with the lighted end resting on the upper, left side of your chest and the beam shining on the wall by your feet. As you watch the beam, you should be able to see it moving up and down as your heart beats. You may have to adjust it a bit to get it to a place where it will stay in place and show the beating very well.

Once you can see your heartbeat, time how many beats you see in 15 seconds. If you have a lighted clock, you can time it yourself, or you can have a friend time off 15 seconds for you. Multiply your total by 4 and you will know your pulse rate in beats per minute.

Now, lets speed up your heart a bit. Stand up and do a couple of deep knee bends. Run in place for a minute. Touch your toes a couple of times. Lie down again and put the flashlight back in place. Do you notice a difference?

Exercise means that your muscles need more oxygen. This means that your heart must pump more blood to your lungs and then pump it out to your muscles. Your heart beats faster and harder, to pump more blood. If you continue watching, you will see your heart rate slow back down as your body catches up on its supply of oxygen.