In 2010, when the new Health Secretary was elected in Aracaju, a city a few hours along the coast from Recife, he declared he would close all of the region’s academias and allocate the funding elsewhere. Within 48 hours there had been so many complaints through the local radio and media that he was forced to reverse the decision.

“We already suspected it was important to people but from that day on we knew it wasn’t going to close again,” says Braulio Cesar, who spent seven years at the Federal University of Sergipe in Aracaju setting up and evaluating the city’s academia programme.

In Recife, the first Brazilian city to allow citizens to vote on local government spending, the programme was picked as the top priority for three years in a row. “That was amazing,” says Eduardo Simoes, “A health promotion programme being ranked in the top three alongside emergency medical care and education – I’d never heard that before. So the programme hit a chord with the population.”

What really convinces politicians and funders is evidence. That’s why an international team, including Simoes at the CDC and Pedro working with the Brazilian Ministry of Health, has been evaluating the programmes under the umbrella organisation project GUIA (Guide for Useful Interventions for Physical Activity in Brazil and Latin America). Their initial evaluations of the first cities to adopt the academias consistently demonstrate how wide-reaching the programme’s effects on the population were. Thus far, three studies conducted in Recife have all reported positively. Phone surveys show that between 2009 and 2011 the proportion of adults who said they did no physical activity went down from 16 to 14 per cent.

Another evaluation in Aracaju found that those who were currently participating in an academia were 13 times more likely to be reaching the recommended level of activity than those who’d never taken part, showing that the scheme gets people moving who aren’t physically active otherwise. According to the study’s findings, just hearing about the academias, never mind actually taking part, seems to increase a person’s likelihood of meeting recommended levels of physical activity by 60 per cent. Perhaps most surprisingly of all, the effect is contagious – even if they’d never heard of the academias, people in an academia’s locale were twice as likely to be physically active as people who weren’t.

The most compelling findings come from the latest evaluations conducted by GUIA, which has compared not just neighbourhoods within the same city, but cities that have an academia system up and running and similar cities that don’t. The results are just being written up for publication, but they back up the previous findings. “The more the community is exposed to the programme the more activity they do – not just the users themselves but those who are involved tangentially,” says Simoes. People who see the programme in action, or hear about it from their relatives and neighbours, end up doing more physical activity than they would have done if it didn’t exist, even if they don’t themselves take part.

The gyms also connect to local healthcare facilities, offering people a free fitness assessment when they sign up and a re-evaluation every three months. Those who are flagged as having hypertension or being overweight are given a fast-tracked appointment at the health clinic, making the programmes even more popular, Simoes says, because healthcare is so limited for those who rely on the public health service in Brazil.

Researchers at the university in Aracaju also note that those in the programme use less prescribed medication, while also enjoying more obvious health benefits such as weight loss. Even when there are no physical health benefits recorded, the nature of exercise, especially outdoors and in the community, means participants often feel a huge sense of improvement in their mental wellbeing, and in their perception of health – how good they feel. Jessica-Juliana, who attends the Alto de Capitao academia in Recife, tells me that although she joined initially to improve her fitness, she’s also benefited from a huge boost in her self-esteem. Another big draw for her, and many of the other participants, is the variety of classes, which include martial arts, aerobics and dance, changing from one session to the next.

Jessica-Juliana has been attending the academia for three months. On average, people keep going to the academias for two years, although some people come and go with the seasons. Yet even those who drop out of the formal exercise classes are significantly more likely to continue exercising afterwards. That’s one of the biggest challenges, says I-Min Lee, professor of epidemiology at the Harvard School of Public Health. “I think the issue is that we have to sustain the interest. We know human beings are notoriously fickle – you are interested in something and if it doesn’t stay fresh we tend not to engage in it. These classes change so that stays fresh.”