So you flex those fore-arms to impress the women, who always end up walking away (it's okay to admit, we've all been there).  Well what if we could provide you some kind of use for them except for their power of ticket dispensary?  

Well Advancer Technologies has your back, with the Biofeedback Game Controller, a plug-and-play option that used EMG (electromyography) sensors to monitor electrical currents that flow through your muscles with every impulse, and turn them into on-screen control (in this case, navigating Mario in Super Mario 3).  Based on the Arduino development infrastructure, in the video example below, you'll notice that a twinge of the bicep makes Mario jump, a gripped fist means run to the right of the screen.  

The one issue with have is that this would all work fine if you have well defined muscles to differentiate electro-muscular activity...as you can probably tell from the kind of content we write here, we don't mess around with the gym, making this a potential issue.  Regardless, check out the video below.

Source: Instructables