Remaining on his feet after 15 rounds against Muhammed Ali established Canadian boxer George Chuvalo as one tough customer, but some of his toughest, most wrenching battles were fought outside the ring.

Chuvalo lost three sons and his wife to drug addiction. Since 1996, he's been travelling the country sharing the story with the hope it will influence young people to make positive choices.

"If you don't go to school, you have a bleak future to look forward to," Chuvalo said in an interview with the Star after a short morning workout at Peak Fitness in Whitehorse.

"And when you don't have anything to look forward to, when you lack hope, it's easier to go down the wrong path."

And it was the path of drug experimentation, which led to addiction and eventually death for members of Chuvalo's family; something the former Canadian Heavyweight Champion does not try to sugar coat.

"I'll tell you something about being an addict," he said before describing a graphic incident about one son's such dependency

"He'd crap his pants in the morning, but be more concerned about getting his next hit, visit the dealer, shoot up and before thinking of cleaning himself .... his only concern in life was that next hit."

While drugs put Chuvalo's personal life in turmoil, his career in the ring was one of legend. Chuvalo went 16-0-0 in his amateur career, scoring knockouts in each bout before the fourth round.

After turning pro in 1956, Chuvalo was never knocked down once in 93 professional fights. Among those were tumultuous battles with some of the sport's most-feared challengers, including Ali, Joe Frazier and George Foreman.

In 1979, Chuvalo retired as undisputed Canadian Heavyweight Champ, a title he'd held since 1958, and in 1990 he was inducted into the Canadian Boxing Hall of Fame.

But what made Chuvalo most famous were his two bouts against then-World Heavyweight Champ Ali, first in 1966 and again in 1972. Judges awarded both fights to Ali but to Chuvalo's credit, Ali declared him, "the toughest guy I ever fought."

When asked about the encounters, as the 71-year-old Toronto native said he always is, Chuvalo responded with equal parts humour and comraderie about his former foe.

"I always tell people that (fighting Ali) wasn't a whole lot of fun," he said, adding the pair have since become good friends.

"We had two tough fights but now when we see each other, it's with hugs. It's funny how you want to kill somebody in the ring but after it's over, there's this mutual respect ... it's a strange way to become pals."

As to whether Ali's declaration of his toughness was any consolation, Chuvalo said he'd "take the compliment."

With his fighting career behind him, Chuvalo has taken up the battle of keeping kids from drifting toward drugs and alcohol.

"I would like a kid (to come away from my talk) to think about the options when faced with trying drugs, alcohol and cigarettes," said Chuvalo. "To think about the consequences of their actions ... you know when you're young, you think you're invincible, but an addiction can change that."

And the boxing great is in the Yukon this week to share his story.

It's a story that Marie Sterriah of the Kaska Dena witnessed in Dawson City last year where Chuvalo spoke. So moved by it, Sterriah decided to bring him to the territory again.

"It was powerful, you know, and he talks a lot about the importance of continuing your education and respecting yourself," said Sterriah. "It's a message I think everyone should hear."

Today, Chuvalo was in Whitehorse and tomorrow he will speak in Watson Lake.

On Wednesday, he will travel to Fort Ware in northern B.C.

On Thursday, Chuvalo will be in Ross River. He will wrap up his speaking engagements Friday in Carmacks.