(CNN) Behind the showmanship, the blur of fast times and the resultant gold rush, who is the real Usain Bolt ?

The world's fastest man has committed to just one more track season before he hangs up his racing spikes in London -- a place he calls his second home -- at next year's World Athletics Championships.

But before putting his slightly ailing body through a final onslaught of winter training, a movie documentary plotting his path to a third and final Olympic sprint treble at Rio in August will be released globally in cinemas next week.

"I Am Bolt" is the brainchild of British brothers Ben and Gabe Turner , whose directing show reel includes "The Class of '92" -- the story of Manchester United's fabled footballers -- and "In The Hands of the Gods," which follows a group of young men seeking to meet Diego Maradona.

They were given unprecedented access to the Jamaican sprint legend -- the film opens with Bolt ironing his clothes.

It highlights the occasional boredom of being locked away in a hotel room for much of a season, as he flits from driving a speedboat and quad-bike racing to singing on a Segway when unable to sleep in the middle of the night.

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'Everyone knows Bolt'

Among those to feature are Justin Gatlin , arguably Bolt's greatest rival and the man who has come closest to toppling him from his sprint hegemony.

"Bolt's the ultimate showman," Gatlin tells CNN. "We've never seen anyone like him. He's done so much for the sport.

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"When you think of football, you think of Messi and Ronaldo. With basketball it was always Michael Jordan. You mention track and field, and most people's first thought is Usain Bolt. Everyone knows Bolt."

Gatlin has lost count of the post-race press conferences at major championships where, vanquished again, he has sat alongside Bolt under the media spotlight.

What pervades first and foremost is a genuine mutual respect between them. A telling moment of the film is Gatlin's insistence he would win Rio gold -- and Bolt admitting it was the catalyst to motivate himself when struggling in pre-Games training.

"I remember watching the Beijing Olympics in 2008 when I was out," says Gatlin, who was serving a drugs ban at the time. "I watched him and remembered thinking I wanted an Ali-Frazier rivalry, and I wanted to push him to get to the top of the podium."

'Sprinting's about the alpha male'

If Bolt's career had not coincided with Gatlin's, the American could have won many more global titles. So does he regret that his career timed with that of Bolt at his peak?

"No way man," he says. "I've had rivalries before that push you, like Tyson Gay and Asafa Powell, and then there was Bolt. But if he wasn't there I wouldn't have been consistently running 9.7 or 9.8 seconds.

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"He brought that out in me. He's such a great competitor, he always brings his 'A' game, and I've enjoyed that so much."

Gatlin remembers seeing the fear factor Bolt instilled in his rivals in 2008, something he insists he never suffered from -- although his stumble with 100-meter victory in sight at last year's world championships in Beijing would suggest otherwise.

"Sprinting's about the alpha male, but you could see the fear he'd instilled in the others," Gatlin says. "Already before they took to the line, they had doubts in their minds and that's because of Bolt."

As rivals, they have mostly kept each other at a distance, but they've let their hair down on occasion.

"I remember we drank some bottles and partied until the sun came up," Gatlin recalls of a night in Zurich. "We had a good time, he's chilled, he's a cool dude and he's got real swagger."

'We're like family'

Bolt has a tight-knit unit around him -- his best friend and manager Nugent "NJ" Walker, who declined to be interviewed by CNN, and his agent Ricky Simms look after his affairs on and off the track.

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Both men star in "I Am Bolt," although in Simms' case he says "reluctantly."

The Irishman first came across Bolt when he won the junior world 200-meter title in Kingston in 2002. Bolt was then 15, while most of his rivals were in their late teens and early twenties.

Simms, himself a former runner, was one of the agents proposed to Bolt and his parents, and they went with him.

"There was so much potential then but you never know for sure how things will turn out with injury," Simms says from his home in Monaco. "It's been a great journey and we've worked extremely closely in a very small team. We're almost like a family."

'Refreshingly honest'

Simms has seen Bolt grow from a shy boy into a towering 6-foot 5-inch colossus of the track, one of sport's great entertainers.

I'm nothing without my fans and I'm very happy to share more about myself with you all https://t.co/3NVdK5AZcd @iamboltfilm pic.twitter.com/rqM2WxppUQ — Usain St. Leo Bolt (@usainbolt) November 21, 2016

"He's the same person if there's two people watching or two million," he insists. "That's why people love him.

"We were trying to work out why he's so popular, and what he says is just cool and funny. Were I to say the same thing it just wouldn't be, people would be just like 'sit down.'

"He pulls it all off with a smirk and a smile. He's so honest and he just says it as he sees it. He's just refreshingly honest."

Simms says the film shows that, behind the relaxed persona, Bolt works harder than most. He often gets up at five o'clock in the morning to beat the Jamaican heat, proving himself to be "an animal in training."

There are times when his coach Glen Mills works him to submission on the track

And despite his fame and fortune, the prima donna strops are in short supply. "Nobody's 100% happy all the time so even he has his off days but, even with it, he's a nice person," Simms says.

Businessman Bolt

With his running days coming to an end, Bolt is approaching a career crossroads -- and he's already preparing for life off the track.

"He's invested in real estate, he's got some key sponsors and there's TV work, maybe even Hollywood," Simms says. "We want him to be remembered as a legend of track and field but we want it to go beyond that.

"Take George Foreman, he's probably now more famous for his grill than his boxing, or Colin Jackson, who's better known for his TV presenting than his hurdling career."

No diva

"I Am Bolt" is an honest reflection of the world's fastest man, from his inability to solve a Rubik's Cube to his surprising level of anxiety before his opening race of the season.

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He says to camera: "Am I still fast? I always worry, am I still fast? Am I still the fastest man in the world?"

Co-director Gabe Turner believes you get what you see with Bolt.

"His public and private persona is as close as anyone we've met in the public sphere. He presents himself 100% as he is," Turner told CNN, adding that he never witnessed any diva behavior from Bolt.

"Remarkably not once. The only time he got remotely irritated was when we were at his house. He'd told us not to ring to make appointments but just to hang out whenever, and he only once got irritated when we asked if we could do this or that in our very British way."

'The next Bolt'

Bolt trains under Mills at Kingston's fabled Racers' Track Club, which has produced a multitude of track champions.

Among its wider training group is up-and-coming British sprinter Zharnel Hughes , a 20-year-old who has already been labeled the "next Bolt."

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Hughes says he revels in being able to see the nine-time Olympic gold medalist in action day in, day out.

"He's funny, he calls me captain when I'm at training because I want to be a pilot," Hughes says. "So he'll salute me when I arrive at training.

"He likes to shout at my coach when I'm dying on the track after a hard session: 'Zharnel's time is up.' But the guy works really really hard, it doesn't just come easy."

There are split family loyalties in Hughes' native Anguilla, a British territory. His Jamaican mother is a massive Bolt fan who battered a saucepan with a wooden spoon in celebration when he won at London 2012.

And Hughes is not ashamed to admit she is torn if he races Bolt. "I'm sure she picks me over Usain ... surely?!"

Local boy

In Jamaica, everyone knows Bolt -- his face is plastered all over billboards, while it is not uncommon to see him around in Kingston.

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"It's funny because he didn't use to be this showman," Moore says. "I got that talking to one his teachers, and there's this great clip of him with the Jamaican team at the 2003 World Championships when he was there for the experience. He was just so awkward and shy, nothing like the Bolt we see today.

"I think the whole showman part came in as a way to help him relax for races. It's a bit of an act, but it has a serious function.

"But for all that showmanship and joking around, he's very serious in training. If anything, Yohan Blake is more of the joker. Bolt saves the antics for the big occasion."

And for the big screen.