The Iditarod gave this musher broken bones and frostbitten toes. At 77, he’s not ready to stop racing.

Soon after Jim Lanier wakes up, he sandpapers his feet.

Ever since the 77-year-old musher lost a toe to frostbite on the Iditarod trail and froze several others, leaving them perpetually white and numb, his feet are quick to callus.

"They become so painful," he said last month in his Chugiak home, staring at his misshapen toes. "So I use sandpaper to knock them down."

Over the years, the Iditarod Trail Sled Dog Race has left Lanier callused, frostbitten, broken and bruised. Yet the trail keeps calling.

"It just becomes part of you," he said. "You need to do it again."

Lanier, a retired pathologist, started his 20th Iditarod this weekend, nearly 40 years after his first. He's the oldest musher this year —59 years older than the youngest competitor — and the third oldest to ever compete.

The late Joe Redington Sr. started his last Iditarod at age 80 in 1997, finishing 36th. The late Norman Vaughan completed the race at age 84 in 1990, placing 60th. He returned two years later, at age 86, but below-zero temperatures and a pair of balky lead dogs forced him to scratch.

Perhaps Lanier will mush for another decade and set a new record, he pondered.

"Don't tell my wife," he whispered.

The Iditarod has just become who he is and what he does.

"He is persistent. He is stubborn," said his wife, Anna Bondarenko, punctuating her sentences with laughter. "He's going to die on that trail."

A father of four and a grandfather of five, Lanier keeps his Christmas tree up from Thanksgiving until Easter because, he said, he likes to gaze at it while drinking his early morning coffee. He sings, he writes, he hikes, he reads, he trains dogs.

And he mentors young mushers. That's one of the things he's most proud of.

At a time when the Iditarod's future is in question, with animal rights activists and some mushers taking aim at the race organization, Lanier says he worries about the controversies when reading about them in the news, but thinks little about them when he's out with his sled dog team — that all feels just the same.

"I hope that doesn't change," he said. "It's too bad the whole thing is politicized."

Lanier said his dogs seem happy and he hopes he's setting a good example for other mushers. But if people have suggestions for a better way to do things, he said, he's willing to listen.

[Report: Iditarod must work to rebuild trust if it wants to survive]

As Lanier talked that day, a 17-year-old musher named Mikah Whitehead listened, pausing after helping to feed Lanier's 30 or so white sled dogs. Whitehead recently completed his first Junior Iditarod. He said Lanier has given him this advice: If mushing is really something you want to do, then do it.

"Don't second-guess yourself," Whitehead said. "Be confident."

Lanier competed in his first Iditarod in 1979 with the sled dogs he kept in his backyard in Anchorage's College Gate neighborhood. It was his first sled dog race. Back then, mushers didn't have to compete in shorter races to qualify for the 1,000-mile race to Nome. Lanier said he lost the trail several times.

"I think partway through the race I called home and I was 39 at the time and my dad said, 'You better make good on this race, you're not getting any younger. You're not going to be able to do this again,' " Lanier recounted.

"I was fearless then, now I'm just stupid," he said.

On the Iditarod trail, Lanier has broken ankles, ruptured his Achilles tendon, broken his clavicle, cracked his ribs, caught pneumonia and frostbit two fingers and a toe, leading to amputations.

"It's a contact sport. I have contacted a lot of things," he said. "So I'm gradually, slowly but surely, disappearing as I go down the trail."

The lows are deeply low in the Iditarod, he said, but the highs are so high.

"A down time is when you're either lost or so tired or so cold that you don't think you can manage to keep going," he said. "An up time is when you have managed to keep going and you get through it and you see the lights of the next checkpoint and the dogs see them too."

Lanier said he has no secret regiment or diet that has kept him fit enough to mush through his 70s.

He begins each day with a series of stretches — after he makes coffee and after he looks at his tree but before he sandpapers his feet. He said he also sings. ("It keeps the attitude up.")

Plus, Lanier said, he typically loses about 25 pounds each year as he ramps up Iditarod training, dropping to a weight of 180 on his 5-foot, 9-inch frame.

"That's the best thing I can give you about how to stay in shape," he said.

In an attempt to avoid more broken bones and bruises, Lanier is wearing shoulder pads, elbow pads, and knee pads during the 2018 Iditarod, as he has the past five or so years. He's also wearing a helmet.

Lanier said he hopes to simply finish this year's race and "maybe have a good time." He has never been a particularly competitive musher — his best finish was 18th in 2004. He has scratched from his last three races because of a series of injuries and illness.

Lanier said he never meant to mush this long, to leave so much of himself on the trail.

"If I can inspire anybody to follow me, when you're getting old and gray, all the better," he said.