RIO DE JANEIRO , Brazil ( CNN ) -- Flavio Canto spent most of his teenage years training in judo , in hopes he would achieve Olympic gold . But today , the Brazilian athlete considers his defeat at the 2000 Olympic trials one of his greatest victories . More than 1,000 students are enrolled in judo athlete Flavio Canto 's Reaction Institute . The loss led Canto -- who later won bronze at the 2004 Olympic Games -- back to his native Rio de Janeiro . Since then , he has helped thousands of young people from the city 's toughest shanty towns find hope in the midst of hardship . `` I 've never seen any place as beautiful as Rio de Janeiro , but it does have its dark side , '' said Canto , 34 . `` There is violence all over . '' Millions of poor families populate Brazil 's favelas , or shanty towns , and roughly 60 percent of the country 's homicides happen there , according to Brazil 's Institute of Applied Economic Research . The favelas ' vulnerable youth face two constant challenges , Canto said : falling victim to the violence or choosing to become a young perpetrator of it . `` It 's the kids who have it toughest , '' said Canto . `` They are told every day , 'You 're not going to advance . If you are born in the favela , you 're going to die in the favela . ' And that 's an idea that we try to break . '' Through his Instituto Reação ( Reaction Institute ) , Canto empowers youths by providing free judo training and education programs . Do you know someone who should be a CNN Hero ? Nominations are open at CNN.com/Heroes . `` We have a very strong pull to attract the kids . They come here thinking they 're going to learn to fight , '' said Canto . Once in the program , instead of fighting in the streets , youths `` learn to fight the proper way -- only in the dojo [ judo arena ] . '' Watch Canto and his students in action in the dojo » . Although Canto has spent most of his adulthood mentoring favela kids , he said he did not always know how to help . But while volunteering in a government-sponsored judo training project in 2000 , Canto said he realized that sports were a powerful tool to change people 's lives . The project lost its sponsorship soon after , and Canto was the only one to continue training the children . He sought help from friends and family to sustain a judo training program for the favela youths . After he collected $ 3,000 through monthly pledges , the Reaction Institute was born . Every youngster in the institute must participate in judo and educational classes Monday through Saturday , year-round . Canto said the institute teaches the values of discipline , humility , courage and determination through judo -- Japanese for `` gentle way '' -- and applies them to other activities . Since 2000 , Canto 's institute has grown to four locations throughout Rio . More than 1,000 students are enrolled in the program , but Canto hopes to continue expanding to meet an ongoing need ; there are 500 children on the waiting list in Rio 's largest favela , Rocinha , alone . Diego Cardoso dos Santos , 21 , credits Canto and his judo training for earning him a scholarship to attend a private university and for helping his 11-year-old brother , Joao Victor , heal . Watch how Canto 's program helps Victor and other favela youths » . Victor witnessed his father 's murder when he was 6 years old and joined the institute a short time after . Today , he has more confidence and pride . `` I am learning more and more and developing myself , '' Victor said . `` My friends think that one day we can be like Flavio . He was [ about ] 13 , a little bit bigger than me when he won with the black belt . It is incredible ! '' Canto said the inspiration goes both ways . While teaching his students to fight for their dreams , they inspired him to continue pursuing his . In 2004 , he earned an Olympic bronze medal in Athens , Greece . But for Canto , the long-awaited achievement was n't just a personal victory . `` We won an Olympic medal in Athens , '' Canto stressed . `` They were there with me . If they did n't exist , the medal would n't exist . '' But seeing his students excel both in judo and academics is the best reward , said Canto . `` We now have college graduates and national champions . I have some kids who will be ready for the 2012 Olympics , '' he said . `` They do n't need to just follow the destiny everyone told them they would have . They can change it . They 're the true heroes . '' Want to get involved ? Check out the Reaction Institute and see how to help .
Bronze medalist Flavio Canto helps young people through free lessons . More than 1,000 Rio de Janeiro youths are enrolled in his Reaction Institute . Judo teaches discipline , humility , courage and determination , Canto says . The Olympics have been a boon for the city of Rio, which has seen its population grow by more than 20 percent since they began in August 2014. Nominations are open at CNN.com/Heroes .