Thursday, January 14, 2010

Know your own strength.

I've been going to the gym a lot lately with my Mom and sister. It's been fun. Sister is a bridezilla and I need to get into shape for her wedding. Actually, since I've been back at it I have so much more energy and just feel better in general.

Jayme knows a lot about working out and takes a very scientific approach to staying in shape. She tells me to think of it all as a big math equation. The Christmas cookies you eat are really just a number of calories in and you need to equal that number out in calories burned to maintain your shape.

As I was swinging along on the elliptical up in the top part of our gym the other day I looked down over the room of cardio equipment and thought about all the calories being burned. All of the machines have their own little TV set so you can watch Restaurant Makeover or CSI as you jog. They are all plugged into the electrical grid of the building. I started thinking about all of the energy we were using to burn the excess food energy we consumed. That was sort of depressing. Wouldn't it be easy enough to design exercise equipment that captures all the food energy our bodies work so hard to convert?

When we're talking about units of food energy we generally think of the number of calories in an item of food. When we talk about energy we generally think in terms of joules. One joule is the amount of energy exerted by the force of one newton moving an object by a distance of one metre (a newton being the unit of force).

One calorie is equal to 4.2 joules.

Therefore, if I burn 300 calories in half an hour I spend about 1260 J of energy. This energy is given off as heat and the forces required to turn the wheels in the elliptical cross training machine.

One joule of energy is required to produce one watt of power for one second. Power being the rate at which energy is converted from one form to another. A watt is a unit of power and we use it describe mechanical energy.

A 60 watt light bulb uses 60 watts of power per second. If we managed to capture this 1260 J of energy we could light a 60 watt light bulb for 21 seconds.

Now, I know this doesn't seem like much, but before we tried to power the light bulb all of my expended energy was just a by-product of this system plus we were taking in, and using, energy that was produced externally. I don't know enough about all of this to explain how energy is captured, but I know that the process is not perfect and we lose a lot of energy in the conversion process. I'm also pretty sure that we have the technology to hook all those ellipticals up to transformers and amp up all of this energy to power the entire place.

I would love to workout at a gym that was off the grid. I bet it could even contribute to the grid. I hope that somewhere someone is already designing this system. I mean, we have all the gear, it's just the good planning that needs to come together.


  1. First of all I want to say "nerd". But really that is a totally good idea and I would go to that gym for sure. I hope it's being worked on somewhere by someone.

  2. Thanks! Yeah, I figure someone from one of thsoe countries that loves good design, like Sweden or Denmark, is already all over this. You heard it here first though.