The rare endurance animals who finish the Iditarod Trail Invitational to McGrath or Nome can count themselves among the toughest bikers, skiers or runners in the world.
And at least one aims to show he's pretty flexible too.
Anchorage bicyclist extraordinaire Peter Basinger, who owns the Invitational record to McGrath -- a stunning 3 days, 5 hours, 40 minutes -- will slip out of the pedals and strap on the skis Sunday when Alaska's longest human- powered race begins at 2 p.m. on Knik Lake.
Basinger is attempting to become the first athlete to hold the race record in two different disciplines while becoming the first skier in race history to reach Nome. Only two other skiers are in this year's field of 50 athletes, and both intend to stop in McGrath after 350 miles.
"He's also a phenomenal skier," said Kathi Merchant, co-director of the race who last year set the women's bike record to Nome. "I think he wants to do something different."
Last year Basinger, 27, biked to Nome in just over 18 days -- faster than three of the first four winners of the Iditarod Sled Dog Race, a time that co-race director Bill Merchant calls "amazing in way less than ideal conditions.
"Pete's time from Shaktoolik to Nome was only five hours slower than Iditarod winner Lance Mackey with his dog team," Merchant said.
Perhaps more than any other Alaska race, times in the Invitational depend on weather.
Merchant and Barry Stanley, former owner of Rainy Pass Lodge, flew part of the trail last week and saw fresh snow in Skwentna and Puntilla Lake, brushy conditions near Finger Lake and what appeared to be thinning snow around the Tatina River and headed into the Farewell Burn.
Merchant knows all that can change overnight.
"It could be a highway right now and a walk all the way to McGrath by race day," he said. "I can promise you this about the trail: It won't be the same as any other year."
Here are some top contenders:
• Jay Petervary of Jackson, Wyo., the defending 350-mile champion, who finished in 3 days, 14 hours, 20 minutes last year but is nursing a sore knee. Petervary won the two-week-long Great Divide Race through the Rocky Mountains from Canada to Mexico in 2007. This year, Petervary is entered along with his wife, Tracey. "We'll see how strong love is versus competition," Bill Merchant said.
• Rocky Reifenstuhl of Fairbanks won the Fireweed 400 bicycle race in 2007 at age 55. He's a former Alaska Mountain and Wilderness Classic champion, too.
• Jeff Oatley of Fairbanks, a former champion in the 350-mile bike race, is the record-holder in the Fireweed 400 and has completed the Race Across America
• Geoff Roes of Juneau, who plans to run the 350 miles to McGrath, is coming off a remarkable year. In August, he won the Wasatch Front 100-Mile Endurance Run in 20 hours, 1 minute, 7 seconds, the fourth-fastest time in race history. Roes won two 100-milers and finished fourth in the Crow Pass Crossing backcountry marathon from near Girdwood to the Eagle River Nature Center last year. And in June, Roes covered about 1,400 miles before dropping out of the epic Great Divide Mountain Bike Race, a 2,490-miler from the U.S.-Canada border to the U.S.-Mexico border.
• Louise Cobin, 40, of Los Gatos, Calif., won Ironbike Italy last year but is coming off a foot fracture. Last year, according to Kathi Merchant, "she was really fast to Puntilla but then got sick when her asthma kicked in."
Meanwhile, looking to extend his record of three Nome finishes in the 1,100-miler is Pennsylvania ultra runner Tim Hewitt, who struggled to finish last year while becoming the first racer to reach Nome three times. Bill Merchant, who traveled much of the way with Hewitt in 2008, was surprised to see him back.
"I didn't know whether to offer him congratulations or condolences for the Alzheimer's you've come down with," Merchant said.