The hard sparring and painful miles on the hills of Big Bear, California, carry little hardship for 35-year-old middleweight king Gennady Golovkin compared with life as a child in Kazakhstan in the early 1990s.
Food and water were scarce, and he had to fight to survive.
He is boxing's most feared puncher, and can rightly be regarded as a great if he beats Mexican poster boy Saul 'Canelo' Alvarez on his Sin City debut today (from noon New Zealand time). After the faux strain of the Floyd Mayweather-Conor McGregor fight last month, this contest pits two destructive forces at the elite of boxing's firmament against each other.
The making of Golovkin as a fighter - and a man - took root in Karagandy, Central Asia, in his formative years, just as the state was newly franchised from the old Soviet Union.
And very messy it was.
Golovkin was just nine years old, and growing up in a tough, blue-collar neighbourhood in a time of scarcity. He lost two older brothers who died serving in the Soviet Army, and that impacted heavily on the young boy who has become the knockout artist now known simply as 'GGG'.
Golovkin explained: "It was a very difficult time after the fall of the Soviet Union. Jobs were difficult and you had to fight to have anything nice."
His father - also Gennady - worked long hours down a coal mine in Karagandy. His mother, Elizabeth, who was originally from a refugee Korean family to the USSR, was an assistant in a chemical laboratory.
Golovkin was one of four boys - he has a twin, Maxim - and, as a young man, he suffered tragedy twice when his older brothers, Vadim and then Sergey, died four years apart while serving in the Soviet Army.
Kazakhstan was a survival-of-the fittest society back then, and his older brothers knew they had to toughen him up. They would walk around the streets, picking fights for him with grown men.
Golovkin said: "My brothers, they were doing that from when I was in kindergarten. Every day, different guys."
A career in the mines awaited him, had he not been invested into the Kazakh boxing programme as a teenager.
Golovkin, unbeaten with 33 knockouts from 37 professional fights, said: "I never went into the mine. But I saw my father and other men coming out, day after day, their faces and bodies covered in soot. It looked very hard and dangerous."
The fear of being forced to work down the pit drove him on as an amateur boxer, finishing as he did with a staggering 345 wins and just five losses. He won an Olympic silver medal at the Athens Games and a world championship gold medal in Thailand, both at middleweight.
Early on, Gennady discovered that he had amazing power in his hands.
"From the beginning, when my brother Vadim first took me to the boxing gym at 10, I was able to punch hard and the coach always put me with older boys because of that. My brothers first brought me to boxing. I dedicate the fights to them and my father and fight for my family."
His twin, Maxim, joins the fighter at every training camp for the last month.
"He's an important figure," said Abel Sanchez, Golovkin's trainer.
"You have to remember it was a very difficult time for everybody, not just his family but the whole country. Kazakhstan became a country and all of a sudden they didn't have the backing of the USSR. Food was scarce, water was scarce, security was scarce.
"The country took two or three years to rebound and become a country. I think it was difficult for everybody there. The times made people much more mentally tough. Him and his brother had to fend for themselves a lot. They had to fend for the family a lot."