12 October 2010
There are some pretty backwards energy using devices we use on a daily basis, the most bizarre one of these in my opinion is energy usage while we work out. When you really think about it we are using electrical energy to burn calories (burn our own energy), which means we are not only using our OWN energy, but also the energy to run machines. Using energy to use our own energy, pretty strange. I looked into how much energy is used running on a treadmill for half an hour:
This website http://www.treadmillsusa.com/HPnotes.htm tells me that the average treadmill uses about 2HP (anywhere from 1.75 HP to 3.00 HP). There are 750 Watts in 1 HP, so a 2 HP motor uses about 1500 Watts. For half an hour this is 0.75 kWh (1.5 x 0.5kWh ).
How does this compare with how much energy our bodies use running for half an hour? I burn about 590 calories per hour running (295 calories per half hour) according to this site: http://www.nutristrategy.com/activitylist4.htm.
With 295 Calories per half hour, this comes out to 0.000319825 kWh per workout. Comparing this to the 0.75 kWh per workout on a treadmill, running outside or around a track uses 0.0004% of the energy you would in a gym. This means you would have work out for half an hour 2,345 times to use as much energy as the treadmill is using in the half hour you run on it (or for 1,172.5 hours (48.85 days).
It is ironic that we use so much energy getting around in cars every day and then need to spend MORE time burning more of our own energy because we didn't use any of it during the day. I can recall many days before this project when I woke up, got on a bus to school, sat at a desk all day and then got on a bus, sat in my house for a few hours before bed and then slept. Literally the farthest I would walk is up or down a flight of stairs (and I wouldn't even have to do that if I didn't want to, I could have taken the elevator). Point being, our society is built around using energy to minimized the energy we need to use ourselves. This isn't helping us, however, because we end up having to use that energy somehow (working out) or our 'unused energy' in the form of food eaten just turns to fat, making us unhealthy.
It is interesting to consider a workout on a treadmill as an 'energy loss'. There are no positive benefits from the energy the treadmill uses, but there are positive benefits for the energy our BODIES lose. How can we use our own energy without wasting other energy?
_bicycle commuting
_walking to run errands
_take the stairs
_running outside, or around a track
_using workout machines which only rely on your own energy
It really does make a difference, to your health and to the health of our environment.
