Union Glacier camp was bulging at the seams in mid-November, with an Ilyushin delivering 54 marathon runners (2 of whom pulled out before the event), a few support staff and organisers, and a Chinese film crew. The annual Antarctic Ice Marathon has become big business, with all available places booked a year ahead – unless ANI staff based at Union Glacier choose to run as supernumeraries (5 did this year – making the largest total field ever, of 57 runners).

The event was promoted as a marathon and a 100 km run, with the two races run on different courses on consecutive days. The 100 km race is ten laps of a relatively sheltered 10 km loop near camp (this track is kept groomed throughout the summer season, for ANI staff and guests to run, walk, ski or bike). The marathon is two laps of a 21.1 km loop that ventures further out onto the glacier, exposing runners to the full force of the katabatic winds that flow down Union Glacier.

The event had its genesis in a one-off South Pole marathon run by ANI in 2002. The winner (British runner Richard Donovan) continued on to organise extreme marathon events on sea-ice at the North Pole (since 2002) and in Antarctica. The 2014 event was the 10^th Antarctic Ice Marathon, which was first run at nearby Patriot Hills (ANI’s previous blue-ice runway) in January 2006. The second marathon was held the same year (December 2006) before November was settled on as the annual date. The runway, camp and marathon were shifted to Union Glacier in 2010. There are other Antarctic marathons run most years, including staff events at McMurdo and South Pole stations, and a ‘public’ marathon run on an ice-free portion of King George Island at the tip of the Antarctic Peninsula. The marathon hosted by ANI at Union Glacier is promoted as the only ice marathon run on the Antarctic continent that anyone can sign up to participate in (provided that they have the entry fee of 10,800 euros, and book a year or more in advance).

Marathon runners push their bodies to physiological extremes. Even in temperate climes, they must battle blisters, dehydration, muscle fatigue (lactate build-up), cramp, sprains and strains, and (potentially) sunburn, heat stroke, electrolyte imbalance and rhabdomyolysis (when muscle tissue is broken down due to the body running out of fuel). When running on snow and ice, there are the additional risks of hypothermia (especially with sweat freezing), frostbite or other cold injuries to extremities (noses, fingers and toes especially), snow blindness, toe-bang from variable footing (cf. hard flat surfaces), additional soft tissue damage from running on an unfamiliar soft surface (or unanticipated changes between hard ice and soft snow, exacerbated from low light contrast/white-out), and slipping on ice. Polar environments are also very dry, exacerbating dehydration, and the Antarctic has higher levels of burning ultra-violet light due to ozone depletion. But the Antarctic Ice Marathon presents fewer risks than the North Pole Marathon (which is 8 x 5 km laps). We don’t need to position sharp-shooters around the course for polar bear protection, and there is zero risk here of breaking through the ice. Union Glacier camp is about 750 metres above sea-level, on ice more than 1 km thick. If all the ice were to melt, the camp would be over a fjord 300 metres deep. However, one risk present here but not in the Arctic is falling into a crevasse. This is all-but eliminated by the ANI Travel Safety Team surveying the entire marathon route with ground penetrating radar, then grooming the track with a 3 ton snow-tractor (i.e. an 80 kg runner is unlikely to bust a snow-bridge that the machine hasn’t).

In most years, the marathon is run the day before the 100 km race, so that people who have completed the shorter but more iconic event can subsequently run the longer distance if still in good shape. This year the 100 km race was run first, as poor weather had delayed both events a couple of days, and it was thought that the 10 km track would be more sheltered, allowing one race to be completed in advance of forecast improving weather. The six runners who chose to participate experienced brutal conditions, with strong winds gusting up to 25 knots, and blowing snow. The event was won by Chinese runner Penbin Chen in a time of 13 hours, 57 minutes and 46 seconds. The two last runners finished together in about 6 minutes less than 24 hours, about 5 hours before the weather cleared and the actual marathon was run in superb conditions. All six 100 km runners completed the course, but were shattered, and chose not to run in the marathon (although all had intended to run in both). Penbin was the focus of a documentary being filmed by the Chinese film crew, who expect that the documentary will be viewed by an audience of more than a billion people. The course record of 11 hrs 21 min 46 sec was set by Czech world champion ultra-marathon runner Peter Vabrousek in 2013, the day after he set the ice marathon course record of 3 hrs 34 min 47 sec.

My role during the marathon was to be part of the second shift at a checkpoint 6 km from camp, providing hot and cold drinks, snacks, a camera-shutter finger and encouragement. Transport to the checkpoint was on a mattress on a sled towed by a skidoo. Both the ride and the checkpoint were good fun until just after the final runner passed through. We packed all the equipment and supplies into the large orange 4-wheel drive van, and promptly bellied it in soft snow. My companion and I were very late for dinner, as it was close to two hours of fruitless digging before a Tucker Sno-Cat arrived to pull us out.

The race was won by ANI weather forecaster Marc de Keyser, in a time of 4 hrs 12 min 21 sec, about 4 min ahead of the first non-staff runner. It was Marc’s second Antarctic Ice Marathon victory, plus he has won the 100 km event twice. The last runner (or, more properly, walker) completed the event in 9 hrs 15 min and 30 sec.

The event’s popularity led to the development of the inaugural World Marathon Challenge in January 2015. This began with a field of 12 runners at Union Glacier starting to run when the Ilyushin took off from Punta Arenas heading south (for a 4 hr flight flowed by a 2 hr turn-around). They then continued to run a marathon in each continent for seven consecutive days, with races at Union Glacier, Punta Arenas, Miami, Madrid, Marrakesh, Dubai and Sydney. The event sold out within 48 hours of being advertised. Richard Donovan has already completed the seven continents – seven marathons challenge in a private capacity, managing to complete all seven in just 4 days 22 hrs 3 min.

Te Papa vertebrate curator Dr Colin Miskelly visited Antarctica during November-December 2014 as a guest lecturer for Adventure Network International (ANI). This is the fifth in a series of blogs based on his experiences in Antarctica, and particularly at the Gould Bay emperor penguin colony in the southern Weddell Sea.

Previous blogs in this series:

Flying south

Camping at 79 degrees south

Camping with emperors

The southernmost penguin colony

Subsequent blogs in this series:

Workhorses of Antarctica

Wildlife of Gould Bay

The end of the world