http://www.cnn.com/2012/07/14/world/americas/brazil-alternative-sentence-reduction/index.html
For hours at a time, Ronaldo Marcelo Wanderlei da Silva pedals on a stationary bike for a cause. But it is not an ordinary bike, nor an ordinary cause. Da Silva is an inmate at the prison in Santa Rita do Sapucai,Brazil, near Sao Paulo. He is among a small group of inmates who have been given the chance to lower their sentences by exercising on customized stationary bikes attached to car batteries that charge as they pedal. The batteries are in turn used to power street lights in the local plaza. Read more at CNN
Customized exercise bikes that charge as they pedal
