Christopher Mims: >The average human expends between 100 and 200 watts of power when exercising vigorously, but your iPhone can only accept up to 2.5 watts when charging. Somewhere, somehow, there’s got to be an inexpensive and reliable way to connect these two realities. I hear that [submerging humans in goo](https://f3a98a5aca88d28ed629-2f664c0697d743fb9a738111ab4002bd.ssl.cf1.rackcdn.com/the-matrix.gif) works pretty well.