If you're brave enough to pull yourself together and go running through wintry early mornings and dark afternoons, then you probably want some sort of flashlight with you to ensure you know where you're going and help you keep safe. If this concept were put into practice, you'd no longer have to, and you'd be helping the environment by avoiding disposable batteries.
Developing an idea seen in those 90s trainers with hell lights, the LED would be powered not by a flat battery but by your own kinetic energy production and give you five foot of light ahead and a green taillight in the back.
For a better idea of how the concept would work, check out DVICE, or you can indulge in all things conceptual with our prototypes category.
Dumb idea. It makes more sense to use a headlamp.
The idea is good but it has some disadvantages also..if the battery is flat