I’ve always kept a lifelist. It’s not written down any place, and really it’s more like an informal tally of ambitions and pipe dreams than a list: skydive, play the ukelele, own a sailboat, live someplace where they don’t speak English.

Like any good top ten list, mine is prone to whimsical deletions (’climb to the highest point in all 50 states’ died when I visited Nebraska and Kansas), and it tends to be appended under the influence of a few beers (why else would anyone ski off the roof of the Polar Star hut?). Some of the things on the list have due dates, usually big round numbers: Visit all seven continents in a year. Write a novel before I turn 30. Err, well maybe 40.

This weekend I crossed a big one off the lifelist. I ran a marathon.

The McMurdo Marathon is the same length as any other marathon, 26.2 miles. Only it takes place in Antarctica. (From New Zealand Scott Base, follow the bamboo flag poles six miles to Williams Field, hang a right and go seven miles to Pegasus Ice Runway, then turn around and come back.)

Look, no matter where you run it, a marathon is fa (um, in the words of Julie Andrews, that’s a long, long way to run). But besides being the southernmost organized marathon in the world, the McMurdo Marathon is the only one whose course is entirely on an ice shelf, 80 meters of glacier floating on the sea (imagine a surface that varies in texture from snow so dry it feels like sand to blue ice suitable for the Stanley Cup, sometimes within a few steps). In fact, entrants in the McMurdo Marathon have a choice of running or skiing.

And then there’s the weather. Even the finest day at 77 South is a reminder that the Boston summer is a long way away.

How did I manage to run a marathon, this marathon? Joolee Aurand lives in Bethel, Alaska, where she runs outdoors most of the year. She inspired me to move my McMurdo workouts from the comfort of the treadmills in the squalid little quonset hut we call the gerbil gym. Even when the temperatures hovered around zero and I frequently resorted to covering my socks with plastic bags to keep from getting frostbite, the two of us, often with a selection of our best running pals (Cece, Traci, Paul and Bija, Michiel), racked up some pretty good mileage on the trails around the Hut Point Penninsula this season.

So yesterday’s conditions, 34 F with 20-24 knot winds weren’t the worst we’ve run in. (Hell, it was above freezing for most of the day.) But at East South East, the wind was straight into our faces from mile 13 to mile 20 (the turnaround at the halfway point at Pegasus Ice Runway to the left turn at Williams Field). The 24 skiers and runners who finished the full marathon were unanimous: that part sucked. Bad.

There were a couple of miles in that stretch were I not only thought that I would never finish, but I was certain I would die–the notion of curling up around a bamboo flag and becoming one with the ice shelf sounded pretty pleasant. Thankfully, Joolee just laughed at my moaning about imminent demise, and finally with a crosswind, we plodded the last five miles back to the finish near Scott Base.

So there it is. Marathon? Check. And with three years to spare before I’m forty. I’ve done it. In Antarctica. And I’ve got the t-shirt to prove it.

As of today I don’t really care to do it ever again. Unfortunately, I know myself well enough. Give me a few months and the misery will become a distant memory. Throw a couple of beers into decision making process and maybe I’ll cook up a plan to run a marathon on every continent. Before I turn forty.

…or maybe I’ll buy a ukelele and get cracking on that novel instead.