REPORTER:  Thai Neave

This is the grassroots of Cuban boxing. It's a gym, set up on a previously unused block of land in a poor part of Havana. It doesn't look like a place that could breed future champions, yet this small Caribbean nation has produced more Olympic gold-medallists in the ring than any other country.

LUIS PEREZ DUVERG, TRAINER (Translation):   Come on, defend yourself.

If Cuba's surprising boxing success is any guide 8-year-old Cesar could have a good chance at a brighter future. There's no doubt about his passion and dedication to the sport -- he already trains and spars six times a week. Cesar wins this bout in less than a minute.

CESAR (Translation):  When class finishes I always ask my teacher...to give me... the boxing gloves so the others see me with boxing gloves on my way to the ring.

REPORTER (Translation):  What do your parents say when they see you boxing?

CESAR'S MOTHER (Translation):  Tell them what I always shout.

CESAR (Translation):  "Go on! Beat him! Beat him!"

In Old Havana, little has changed in over half a century. And something else that hasn't changed is the Cubans love of sport, baseball and football are popular but it's in the ring where they've had the most success. The Cordoba Cardin tournament is the big annual event in Cuban boxing, attracting amateur fighters from around the world. Tickets are cheap and the locals are here to back the home team.

CROWD (Translation):  Go Cuba! Go Cuba!

National pride is at stake for the final bout of the tournament. Talented local hope Yoandy Toirac is taking on Chinese star Zhilei Zhang. The fighters are treated like rock stars, but they're paid only in praise.

REFEREE (Translation):  And the winner is Red Energy.

Cuba's talented boxers, often considered the best in the world, can't make millions of dollars fighting as professionals. Instead like most other Cubans they survive on a mere $20 a month.

JUAN HERNANDEZ SIERRA, CUBAN NATIONAL TRAINER (Translation): Things have to change for the better. So, athletes... they strain themselves, they make sacrifices and in my opinion, they should be rewarded for that sacrifice.

For boxers maybe things are changing for the better. For the first time in 53 years they're now allowed to fight for prize money without losing their amateur status.  But Cuba is not abandoning its socialist principals.

ALBERTO DE LA BARCA, CUBAN BOXING FEDERATION (Translation):   This prize money is for the boxers, for their trainers, for the doctors, the physiotherapists and even the cook who has participated in the process of...  training and preparation for this challenge.  So the prize is not exclusive to the boxer.  We give the prize to whole teams.

Cuba's boxers haven't always been poor. In the ‘50s Cuba had six highly paid professional world champions. But when Fidel Castro came to power in 1961 he outlawed professional sports, many boxers were forced to fight for country instead of cash.  Today, Havana is still feeling the effects of the revolution. The US trade embargo has been tough on Cuba. The waterfront esplanade in Havana, the Malecon, with its barely surviving 1950s American cars is symbolic of the decaying city.

Cesar's nameless gym lacks almost every amenity. Energy and commitment make up for gear that's worse for wear. Luis, the trainer, arrives when the boys have finished school each day.

LUIS PEREZ DUVERG (Translation):  My hand stretches out and back in a single swing, swing out and in. Now you try it - if you do it well, we will move on.

Kids as young as four are already learning the basics. Luis is employed by the government to nurture and identify talent with the hope that one of his fighters will end up in a more advanced academy - here discipline is paramount.

LUIS PEREZ DUVERG (Translation):  Harder, harder - don't lower your hand. Don't lower your hand! Don't lower it!

The kids mean a lot to me, I have always liked working with kids even though, as an athlete, I was disciplined, I was sanctioned for four years because I was disrespectful towards the trainers. So I don't want these kids to be like me.

CESAR (Translation):  He makes us train in the evening at any time and when we finish training, he always gives us a hug.

Cesar's family live in conditions similar to many of Havana's residents, but they believe that the local gym offers both refuge and a better future for their son.

CESAR'S FATHER (Translation):  It would mean a lot to us, there hasn't been a champion in our community so far. If we had a champion from San Miguel Street, from the gym that we built ourselves and that we have all helped with, it would be the best thing that could happen.

In nearby Old Havana, is the Rafael Trejo Boxing Gym. Built in the 1930s, this crumbling place is the city's symbolic home of the sport. To this day it's still the training ground of Cuba's  best boxers, where kids like to  Cesar might one day compete, if they make the grade.  Some of the old timers here remember Cuba's days of glory when its professional boxers were world famous.

MAN (Translation):  Kid Chocolate is also there. He was a pro, a boxing champion.

Kid Chocolate, Kid Gavilan, Sugar Ramos, even though their golden age is now long past they're still regarded as national heroes. But when Cuba banned professional boxers it was amateur champions like Teofilo Stevenson who replaced them in the nation's heart. Stevenson won three Olympic gold medals and once declared he would prefer the love of millions of Cubans to the millions he was offered to fight as a professional.  And there were other fighters who were tempted.

ROLANDO GARBEY, FORMER WORLD CHAMPION (Translation): We were also approached with offers, but our offers weren't as big as his. Teofilo was a much better athlete in every way, he was far superior to us. But we always put our revolutionary principles first - no amount of money can stand between us and our principals. They are incorruptible.

In the peaceful outskirts of Havana, I'm granted a rare glimpse at the powerhouse of Cuban boxing, the national academy. Over the years it's become a conveyor belt of champions. Equipment here is so dilapidated that it's hard to believe the place known simply as La Finka or "the farm" has cultivated an incredible 34 Olympic champions, including London games gold medallist, Roniel Iglesias.

RONIEL IGLESIAS (Translation):  We give no importance to money and finances and what you can earn. It's true that first and foremost you should really love what you do.

In recent years though a number of La Finka's greatest stars have defected to the USA to chase big money as professionals. As the talent pool has diminished so too has Cuba's medal tally. National coach Rene Aceval is one of the men trying to get the countries boxing back on top. He believes that many of those who have left - regret their decision.

RENE ACEVAL, NATIONAL COACH (Translation):  It's true that some of the boxers over there have earned millions, but they are only a few. The vast majority of them are living in very difficult conditions and some of them are even trying to return to our country.

I've come to Miami to catch up with the boxers regarded as traitors for leaving Cuba. Most Cuban defectors can claim political asylum if they can actually get on to US soil. And while the journey to the self-proclaimed land of the free might look like a relatively short one, getting here often means jeopardizing ever seeing your family and friends again or even worse, death. For some Cuban boxers though, the potential riches far outweigh the risks.

Yunieski Gonzalez was a rising star at the Cuban national academy before taking the dangerous journey to Miami in 2010 to team up with trainer Orlando Cuellar and become a pro.

YUNIESKI GONZALEZ (Translation):  I took a very difficult and risky journey, we risked our lives. We were risking our lives crossing the ocean, but at that point you don't think about the risks, you just think about getting there safely and that you are doing it for your family.

Yunieski says his old team-mates at La Finka are being brain washed.

YUNIESKI GONZALEZ (Translation):   They put thoughts into their heads, saying that they won't make it here and that boxing isn't possible here.

ORLANDO CUELLAR, TRAINER:   Blood sweat and tears. We came to suffer! Sacrifice and suffer!

Orlando has made a career looking after Cuban boxers who have defected. But the transition from amateur to professional can be heartbreaking.

ORLANDO CUELLAR:  You got to remember these are athletes from a poor country, they're not really businessmen, they need advice, now, they are very easily ripped off. So if they get around the wrong people, which it happens very often, all too often - they get ripped off.

YUNIESKI GONZALEZ (Translation):   I came here to become a millionaire, I came here to make money, to send money to my family so they can live better.

ORLANDO CUELLAR:  He's going to get the million, he's on track. He's on his way, he's got the mindframe, he's got the right work ethic, he's hungry enough, and he is resisting temptation in Miami and that alone has got to pat dividends.

Back in Havana, I've planned a special surprise for Cesar and his friend Carlos.  The car is a 1957 Ford Fairlane and they are on their way to meet one of Cuba's favourite heroes. 

MAN (Translation):  Where do you train?

CARLOS (Translation):    In the boxing ring at San Miguel.

MAN (Translation):   In La Cuevita of San Miguel?

CARLOS (Translation):    Yes.

MAN (Translation):  Are you looking forward to the match?

CARLOS (Translation):    I am!

CESAR (Translation):  Me too.

Towering over the boys and passing on some of the secrets that helped make him a three time Olympic gold medallist, is Cuba's most famous living athlete Felix Savon.  It will be a long time before Cesar and Carlos fight for money or the pride of their people, or even whether they'll be good enough to pursue either. For now, they're happy following in the giant footsteps of one of Cuba's national icons.

FELIX SAVON (Translation):   In order to be an athlete you have to be disciplined, you have to be honest, you have to have integrity. That is what the young people need to  learn.

ANJALI RAO:   Thai Neave with Cuba's next generation of champions. He also took a series of evocative still photos while filming that story, take a look at the gallery on our website.

Reporter/Camera
THAI NEAVE

Producer 
ALLAN HOGAN

Associate Producer
CLAUDIANNA BLANCO

Fixer
LUIS CHIRINO GAMEZ

Security
IGOR HEVIA

Additional Footage
LAUREN LAVERCOMBE

Subtitling
HENAR PERALES

Editor
MICAH MCGOWN

Original Music Composed by VICKI HANSEN