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It is, conservatively speaking, about 9 million degrees inside Abel Sanchez's boxing gym in Big Bear Lake, California, and still his prized fighter, world middleweight champion Gennady Golovkin, is in the ring doing chin pushups -- wearing a hooded sweatshirt and sweatpants.

Yes, chin pushups. Arms behind his back, his chin rests on a towel, bearing the full weight of his 170-pound frame. He dips within inches of the canvas and rises back up. At the end of the set, he turns on his back, wraps the towel around his head and face, loops a rope with a weight attached to the end of it around his neck and does a set of what can only be described as blind, hanging, weighted neck crunches. Golovkin conditions each part of his sinewy frame like this, in rigorous isolation drills. The chin must withstand pain. The neck must be strong enough to absorb punches. To give him strength to fight inside, he works his forearms -- which he often has trouble fitting in the sleeves of a normal dress shirt -- with resistance bands and a homemade contraption of steel and rope pulleys that his trainer affectionately calls "the machine."

Decades of such rigorous training have seen Golovkin establish himself as one of the best fighters of his generation. He has defended his middleweight title 18 times over the past seven years, putting him within range of Bernard Hopkins' record of 20 defenses in his division. So it's not surprising that he's had trouble persuading boxing's biggest names to get into the ring with him.

"I understand," Golovkin says. "It's too dangerous. Sometimes it doesn't matter how much money [you offer]; people don't want to lose reputation."

This happens far too often in boxing -- the best fighters simply don't fight one another. It's why Golovkin's Sept. 16 showdown with Mexican superstar Canelo Alvarez is being billed as the superfight that actually will live up to the hype, after Alvarez's dud against Julio Cesar Chavez Jr. in May, Floyd Mayweather's bore against Manny Pacquiao in 2015 and whatever the hell you want to call the Aug. 26 fight between Mayweather and Conor McGregor.

But for Golovkin, the showdown with Alvarez is something far simpler than a bout to save boxing: It's the fight he's waited his entire life for.

Finally, the stage matches his skill and reputation. Finally, a top-flight opponent is willing to risk something of real consequence to fight him.

Finally, a fight feels fair and important, even historic.

"He never really believed that he was going to get to where he's at right now because everybody screwed him along the way," Sanchez says.

When Golovkin lost a controversial decision to Russia's Gaydarbek Gaydarbekov in the gold medal fight of the 2004 Olympics, his disillusionment nearly drove him into early retirement. When Europe's top fighters refused to get into the ring, afraid a no-name boxer would beat them, he worried he might spend his best years in purgatory. In 2010, he left for the United States at the relatively old age of 28, looking for a trainer who could help him get his shot.

Sanchez remembers fondly the call that sealed a seven-year relationship with his fighter. A man claiming to be Golovkin's manager called from an unknown number and said Golovkin was arriving at Los Angeles International Airport from Kazakhstan the next day -- could Sanchez pick him up?

"Aeroflot at 2 p.m.," Sanchez says, smiling at the memory. "Then he comes up the tunnel with one little bag."

One bag? For two months of training in the United States?

Golovkin shrugs.

"I came to train," he says. "Not to party."

Seven years later, he hasn't brought much more to Sanchez's gym. And perhaps even more than before, he knows exactly what is at stake.

"Boxing is serious. It's not a game," he says. "Just one punch -- change life."