FLOYD MAYWEATHER crafted the most iconic unbeaten boxing record of all time by training in sweltering heat in the middle of the night. The American’s gym is just two short miles from the Sin City strip where he collected the majority of his belts and millions in the ring.Floyd Mayweather training in his Las Vegas gymCredit: GettyMayweather’s fight posters, in chronological order, adorn the gym wallsCredit: The SunThe Sun took a trip to the famed boxing clubCredit: The SunBut the real work was done inside the Mayweather Boxing Club, where the 50-0 legend whipped himself into sensational shape. He did so by training at all hours of the night, often as late as 3 am, and with the thermostat cranked up to a boiling 83 degrees (28 C).The Sun took a trip to the iconic gym and experienced firsthand just how hot the boxing club was.And according to Mayweather’s uncle Jeff, his nephew’s influence is so great that up-and-comers force themselves to train in the heat like their hero once did.”Well, that’s because that’s what Floyd used to do and everyone that comes to the gym wants to pattern themselves after Floyd. So they let the gym just heat up and I hate it!” Jeff told us.Mayweather, who officially retired in 2017 after beating UFC superstar Conor McGregor, prided himself on doing things his own way. And to gain a psychological edge he would train in the middle of the night while his opponents slept. So if you were on his training team it meant being on call at all times.Most read in Boxing”He trains some crazy times,” former world champion Badou Jack, 40, said.”I’m not sparring with him but we’d get a call in the middle of the night and he’ll say ‘Get to the gym, we’re working out.'”Ultimate boxing rich list including Anthony Joshua, Floyd Mayweather Jr. and Deontay WilderNot even a night out on the Vegas town would get in the way of his sparring sessions. “Everything he does is different, he does his own thing,” 23-8 Denis Douglin, 35, remembers.”Floyd would go out to the club, finish at three o’clock in the morning and then go and train.”That was regular. It sounds crazy to the world but the man does what he wants, but he stays focused. He’s just on a whole different level.”Mayweather is so impromptu he would often challenge his sparring partners to box until one of them gave up. “Floyd said to me, ‘We’re going to turn the bell off and spar till somebody quits. I’m gonna make you quit,’ Douglin recalls.”I said to him, ‘Floyd, if you turn that bell off we’re going to spar for the rest of the day, because I’m not quitting.’A painting of Mayweather’s family and team members hangs on the wallCredit: The SunThe boxing legend has never been shy of showing off his beltsCredit: The SunPhones were banned when Mayweather was trainingCredit: The SunThe heat was cranked up to 83 degrees (28 C)Credit: The Sun”We sparred about 20-30 minutes straight, but we had to stop because Devin Haney was sparring after us.”If it wasn’t for that we weren’t going to stop – we’d probably still be sparring now.””We’re boxing, going back and forth, we did three or four rounds straight, but Floyd’s the type of guy to try and break you,” Daquan Mays, who is 5-1, added.”He’s looking me in the eyes the whole time, and I’m like this s*** is fun as hell.”We’re in like the third round and he’s like, ‘I ain’t tired, I’ll keep going, I don’t give a f***.”I was like, well I don’t give a f*** either. So he said, ‘Get the clock off, get the clock off, we going until you’re tired, until you’re done boxing’.”Me myself, I didn’t care, I wanted to see where I was at. We did 16 minutes, he gave me props afterwards and that was that.”Mayweather has a custom money-heavy bagCredit: The SunAnd he has a bag with all 50 of his wins recorded on itCredit: The SunMayweather’s gym is full of his favorite memorabilia with fight posters – all in chronological order – draping from the ceiling.There is also a poster of the five-division champ with the quote, “A true champion can adapt to anything.”On the entrance door of the gym are also strict instructions prohibiting phones in the gym whenever Mayweather was training. Failure to do so would see you kicked out of the gym and banned from coming back.But Mayweather is not often seen around the gym these days.He continues to box in exhibitions since hanging the gloves up, facing stars of the social media, MMA, and boxing world.His last was against the grandson of notorious mob boss John Gotti, which ended in a disqualification win last June after a brawl broke out in the ring. Mayweather continues to tease more money-spinning spectacle bouts, meaning there are rare cameos in the gym here and there. READ MORE SUN STORIES”He comes through every once in a while,” uncle Jeff revealed.”He doesn’t really train unless he’s got an exhibition or something going on like that. He’s in the gym sometimes to help other young fighters.” More