# How much energy potential in an average public gym? **URL:** \ **Category:** Factual Questions\ **Created:** [July 14, 2008, 5:47am UTC](https://boards.straightdope.com/t/how-much-energy-potential-in-an-average-public-gym/456407 "2008-07-14T05:47:54Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![Dilton\_Doiley\_Philosopher\_King](https://avatars.discourse-cdn.com/v4/letter/d/f1d935/32.png) [@Dilton\_Doiley\_Philosopher\_King](https://boards.straightdope.com/u/Dilton_Doiley_Philosopher_King)\ **Post date:** [July 14, 2008, 5:47am UTC](https://boards.straightdope.com/t/how-much-energy-potential-in-an-average-public-gym/456407/1 "2008-07-14T05:47:54Z")
Say I wanted to run my own forum and instead of using hamster power, I wanted to use human power. On an average day, how much energy could I tap if I hooked up alternators (or some other energy generator) to all the stationary bikes, treadmills, stair steppers, etc? What sorts of an effect would it have on the exerciser? ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [July 14, 2008, 6:03am UTC](https://boards.straightdope.com/t/how-much-energy-potential-in-an-average-public-gym/456407/2 "2008-07-14T06:03:38Z")
[QUOTE=Dilton Doiley,Philosopher King] Say I wanted to run my own forum and instead of using hamster power, I wanted to use human power. On an average day, how much energy could I tap if I hooked up alternators (or some other energy generator) to all the stationary bikes, treadmills, stair steppers, etc? What sorts of an effect would it have on the exerciser? [/QUOTE] A human being produces at maximum about 750 watts (~1 h.p.) for brief bursts, and sustained output for a well-conditioned athlete is about 250 watts. So, humans would not be able to run the lighting typically available in a gym, much less the HVAC system, music, et cetera. Stranger ---
**Author:** ![AHunter3](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ahunter3/32/368_2.png) [@AHunter3](https://boards.straightdope.com/u/AHunter3)\ **Post date:** [July 14, 2008, 6:37am UTC](https://boards.straightdope.com/t/how-much-energy-potential-in-an-average-public-gym/456407/3 "2008-07-14T06:37:43Z")
Sticking them on treadmills, etc, seems rather inefficient. Are we allowed to convert the matter of their bodies in its entirety to energy, or even burn the combustible parts? Or do you need them alive at the end of the day/hour? Do we have a long line of aditional gymrats to shove onto treadmills (into furnaces, into star trek matter annhilators, etc), or are we stuck with the initial gymload? The damn things wear out eventually no matter what you do, darn it! If I can put them on treadmills and put a mattress full of poison ivy and nettles and stuff for them to fall onto if they don’t keep up, I might get an extra kw here and there, and then stick a new one on each time an old one falls, ja? ---
**Author:** ![The\_Controvert](https://avatars.discourse-cdn.com/v4/letter/t/dec6dc/32.png) [@The\_Controvert](https://boards.straightdope.com/u/The_Controvert)\ **Post date:** [July 14, 2008, 8:25am UTC](https://boards.straightdope.com/t/how-much-energy-potential-in-an-average-public-gym/456407/4 "2008-07-14T08:25:17Z")
I always thought a great way to teach someone to adopt a habit of conserving energy was to hook them up to a treadmill to power some lights for someone else’s room. The treadmill slows down if power is not used, but stays fast even if power is wasted on an empty room. ---
**Author:** ![ignis\_glaciesque](https://avatars.discourse-cdn.com/v4/letter/i/5f8ce5/32.png) [@ignis\_glaciesque](https://boards.straightdope.com/u/ignis_glaciesque)\ **Post date:** [July 14, 2008, 3:38pm UTC](https://boards.straightdope.com/t/how-much-energy-potential-in-an-average-public-gym/456407/5 "2008-07-14T15:38:39Z")
[Wait, didn’t some movie somewhere already explore the possibility of using the human metabolism as an energy source to power machines?](http://en.wikipedia.org/wiki/The_Matrix_franchise) With that one guy from _Bill and Ted_, you know the one I’m talking about? ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [July 14, 2008, 4:22pm UTC](https://boards.straightdope.com/t/how-much-energy-potential-in-an-average-public-gym/456407/6 "2008-07-14T16:22:30Z")
[QUOTE=Stranger On A Train] A human being produces at maximum about 750 watts (~1 h.p.) for brief bursts, and sustained output for a well-conditioned athlete is about 250 watts. [/QUOTE] And I bet your average gym rat can just manage to supply half that. ---
**Author:** ![Trunk](https://avatars.discourse-cdn.com/v4/letter/t/87869e/32.png) [@Trunk](https://boards.straightdope.com/u/Trunk)\ **Post date:** [July 14, 2008, 5:22pm UTC](https://boards.straightdope.com/t/how-much-energy-potential-in-an-average-public-gym/456407/7 "2008-07-14T17:22:15Z")
[QUOTE=Q.E.D.] And I bet your average gym rat can just manage to supply half that. [/QUOTE] Yeah. I’m a pretty in shape guy. I can hold about 170 watts for 20 minutes on the ergometer. I’m small (150 lbs) but I’m in better shape than 75% + of the people at the gym. However, I’m only about 150. Bigger guys can pull more watts. Women much less. 125 watts might be pushing it. I heard that Lance could max 1200 watts, and could produce 400 watts for 45 minutes. That’s simply incredible. Vs.'s tour coverage includes power meters on some rider’s bikes. They’re regularly above 250, but they’re wattage machines. Still, it’s not a terrible idea if one could efficiently store and transmit the energy. You could probably get 3 treadmills/cycles to power a single TV. Apparently, some people have looked into energy “harvesting” [floors](http://www.freerepublic.com/focus/f-news/1751297/posts) that produce energy just from people walking on them. ---
**Author:** ![cainxinth](https://avatars.discourse-cdn.com/v4/letter/c/7bcc69/32.png) [@cainxinth](https://boards.straightdope.com/u/cainxinth)\ **Post date:** [July 14, 2008, 7:55pm UTC](https://boards.straightdope.com/t/how-much-energy-potential-in-an-average-public-gym/456407/8 "2008-07-14T19:55:05Z")
[Human Powered Gyms in Hong Kong](http://www.inhabitat.com/2007/03/08/human-powered-gyms-in-hong-kong/) ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [July 16, 2008, 11:15am UTC](https://boards.straightdope.com/t/how-much-energy-potential-in-an-average-public-gym/456407/9 "2008-07-16T11:15:15Z")
[Human-powered Olympic Trials in Eugene](http://www.oregonlive.com/environment/index.ssf/2008/07/sustainability_comes_in_many_f.html) ---
**Author:** ![JohnnieEnigma](https://avatars.discourse-cdn.com/v4/letter/j/dfb087/32.png) [@JohnnieEnigma](https://boards.straightdope.com/u/JohnnieEnigma)\ **Post date:** [August 20, 2008, 8:22pm UTC](https://boards.straightdope.com/t/how-much-energy-potential-in-an-average-public-gym/456407/10 "2008-08-20T20:22:32Z")
[QUOTE=Dilton Doiley,Philosopher King] Say I wanted to run my own forum and instead of using hamster power, I wanted to use human power. On an average day, how much energy could I tap if I hooked up alternators (or some other energy generator) to all the stationary bikes, treadmills, stair steppers, etc? What sorts of an effect would it have on the exerciser? [/QUOTE] I would think you would get more energy with horse power. ---
**Author:** ![Sleel](https://avatars.discourse-cdn.com/v4/letter/s/73ab20/32.png) [@Sleel](https://boards.straightdope.com/u/Sleel)\ **Post date:** [August 23, 2008, 6:41am UTC](https://boards.straightdope.com/t/how-much-energy-potential-in-an-average-public-gym/456407/11 "2008-08-23T06:41:48Z")
[QUOTE=JohnnieEnigma] I would think you would get more energy with horse power. [/QUOTE] You’re missing the point, and no, actually, you wouldn’t. Horse power became a standard measurement mostly because they were common draft animals who were more versatile than oxen. Humans can put out 3/4 to 1 hp at peak efforts, and keep going long after the point where a horse would have collapsed in exhaustion. Horses are strong partly because they’re big. If you consider strength to weight ratios, humans are among the strongest animals on this planet. ---
**Author:** ![Andy](https://avatars.discourse-cdn.com/v4/letter/a/aeb1de/32.png) [@Andy](https://boards.straightdope.com/u/Andy)\ **Post date:** [August 23, 2008, 10:12am UTC](https://boards.straightdope.com/t/how-much-energy-potential-in-an-average-public-gym/456407/12 "2008-08-23T10:12:32Z")
It’d make prison a less attractive place I think; eight hours a day on an exercise bike to produce power. On the other hand, it would make them harder to catch if they re-offended.