Brazilian inmate Ronaldo da Silva hops on a bicycle and pedals furiously, clocking up several kilometres before slowing down and jumping off.

Silva hasn't gotten far, in fact not an inch. He's still inside the medium-security prison where he's serving a 5.5-year sentence for holding up a bakery, standing next to a stationary bike.

But he did move a bit closer to freedom. Silva is part of an innovative program that allows inmates at a prison in Brazil's southeastern Minas Gerais state to reduce their sentences in exchange for generating power to help illuminate the town at night.

By pedaling the prison's stationary bikes, the inmates charge a battery that's used to power 10 street lamps along the town's riverside promenade. For every three eight-hour days they spend on the bikes, Silva and the voluntary program's other participants get one day shaved off their sentences.

It is one of several new projects being implemented across Brazil, including literacy and book-reading programs, all aimed at thinning out notoriously overcrowded prisons and cutting down on recidivism by helping restore inmates' sense of self-worth.

'Winning our freedom'

Lambasted by critics as too soft on criminals, such initiatives are seen by their defenders as effective ways of breaking the cycle of violence that reigns in the country's penitentiaries.

"We used to spend all day locked up in our cells, only seeing the sun for two hours a day," said 38-year-old Silva, whose missing front teeth speak to a life of hardships and privation. "Now we're out in the fresh air, generating electricity for the town and at the same time we're winning our freedom."

Silva has already pedaled off 4 kilograms and 20 days from his sentence.

Clad in red, prison-issue sweat pants and matching T-shirts, he and his fellow cyclists hit the bikes at around nine in the morning and ride until about 5 p.m., with breaks for lunch and an afternoon snack.

The resistance is strong, and the inmates soon work up a sweat, though the crisp mountain air of Santa Rita do Sapucai — a city of about 35,000 nestled in a mountain range about two hours northwest of Sao Paulo — keeps them cooler than they'd be in most other parts of tropical Brazil. With just four bikes, so far, the project's eight participants take turns relieving one another.

The two month-old program is the brainchild of the town's judge, Jose Henrique Mallmann, who said he got the idea from a story he read on the internet about gyms in the United States where electricity is generated by the exercise bikes.

The municipal police contributed bicycles that had long been lingering in the lost and found, and neighbourhood engineers helped transform them into stationary bikes and hooked them up to car batteries, donated by local businesses. Area entrepreneurs also pitched in the converter used to transform the battery's charge into the 110 volts needed to power 10 of the cast iron street lamps that dot the riverside promenade.

Every night just before sunset, a guard drives the charged battery from the prison, on the outskirts of town, to the downtown promenade. He hooks it up to the converter and a few minutes later the 10 street lamps begin to glow a soft white, like full moons suspended over the rushing waters of the river.

Long abandoned after dark, the newly illuminated promenade now attracts dog walkers, joggers, kids on bikes and couples walking arm-in-arm.

Another guard comes in the morning to pick up the battery and ferry it back to the prison, where 133 inmates are serving sentences ranging from a few months for burglary and drug charges to up to 34 years for murder.

The goal is to eventually kit out enough bikes to allow inmate cyclists to power all 34 riverside street lamps, said the prison's director, Gilson Rafael Silva.

"It's a win-win situation," he said. "People who normally are on the margins of society are contributing to the community and not only do they get out sooner in return, they also get their self-esteem back."

Silva, the prison director, said that his is the first Brazilian prison he knows of to have instituted such a power-generating scheme and added that he'd received inquiries from his counterparts in penitentiaries from as far afield as the northern Amazon rainforest state of Para and in Rio Grande do Sul, in the far south.

Still, biking is not the only way for inmates in Brazilian prisons to win a quicker release.

Reading a way out of jail

In the country's four federal penitentiaries, where the most dangerous offenders are kept, some 400 inmates are reducing their sentences by taking classes and by reading books behind bars.

The so-called "Redemption through Reading" program shaves a month and a half off inmates' sentences for every dozen books they read annually. Under the initiative, inmates are able to choose from a wide range of genres, including literature, science, philosophy and classics.

To guard against cheating, participants must write a summary of each book, which is reviewed by a judge. The magistrate then decides whether to grant a sentence reduction of up to four days per book, according to the decree that appeared last month in the government's official gazette. Capped at 12 books a year, the program can shave up to 48 days a year off of participants' sentences.

That's many times the number of books the average Brazilian reads. A recent survey by Pro-Livro, the lobbying arm of Brazil's publishing industry, suggested the average Brazilian finishes just 2.1 books a year. Though Brazil has made great strides in reducing illiteracy in recent years, one in 10 citizens over the age of 15 still can't read, according to the 2010 census.

In order to combat illiteracy and raise education levels, the federal prisons also offer programs that reduce inmates' sentences in exchange for taking elementary school to college-level classes.

An estimated 500,000 people are serving time in Brazil's prisons, which human rights groups have long complained are plagued by rampant overcrowding, appalling conditions and widespread violence.

The bike initiative and other sentence-reduction programs have come under criticism from victims' advocates and others who contend they coddle people who are meant to be paying for sometimes heinous crimes.

Prison director Silva disagrees.

"People say that we're turning prisons into a kind of luxury hotel," said Silva. "But this is the only hotel I know of where no one wants to stay."