We basically live on our phones, right? Even at the gym—it's simultaneously our iPod, our timer, our coach, and our way to pass the time (yeah, I see you checking Twitter on the elliptical). So, it's no surprise (but no less a total bummer) when we leave a workout and find our battery nearing the dreaded red zone. Soon, you won't need to worry about that, because scientists are working on technology that will allow us to charge our phones with our sweat.
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Yep, you read that right. Researchers at the University of California, San Diego are working on temporary tattoos that will use your sweat to power your electronic devices. The tattoos are basically tiny batteries—their sensors pull electrons from the lactic acid released in your sweat, which then produces a measurable electrical charge. The researchers also noted that the sensors could be built right into your gym wear, which, IMHO, would make $88 leggings totally worth it.
The technology isn't perfect ... yet. Less fit test subjects produce more lactic acid, and, as a result more electrical power; and the total electrical charge measure is still pretty small (not even enough to power a basic watch). But, give the researchers some time, and we bet they'll figure out a way to maximize our sweat. We'd never skip a sweat sesh as is, but one that pulls double duty? Even better.
Stay in shape in a fitness class.