Ice Ultra 100 km:
The ultimate test at the end of the world
2025 - Ice Ultra in Antarctica
When one plan fails, the better one often wins. In 2025, Rainer decided against a third attempt at the North Pole – the race was canceled again for political reasons two months before the start – and opted for the 100km Ice Ultra near the South Pole. No bureaucracy, no waiting, no frustration. Instead: focus. Antarctica. 100 kilometers in his element. He ran in the Trail Addict Pro R with spikes – the wide, stable fit and uncompromising grip provided control on both ice and snow. The successor to the Trail Addict Pro R is called the Trail Addict Flow+.
Preparation on ice – right in the heart of Vienna
Rainer laid the foundation in the United Ice Factories in Vienna:
-28°C in the gym, supplemented by winter sessions in the mountains, acclimatizing mind and body, training in Joe Nimble trail shoes. The trip began with a flight from Frankfurt to Cape Town – 25°C, sunshine, a stark contrast. Nevertheless, training was still possible: treadmill, air conditioning, rest.
Two days before departure: Race briefing, getting to know the international field of competitors. Europe was represented by exactly two athletes: one of them was Rainer. Runners from Brazil, Canada, the USA, China, Singapore, and South Africa were also present. The flight to Antarctica: six hours in a cargo plane. First contact with the ground on the seventh continent – goosebumps.
Not a single step taken yet, but a major partial success achieved.
Ultima Base Camp – A Community on the Edge of Civilization
Accommodated at Ultima Base Camp, container modules for around 120 people: a small group of runners and tourists, the rest researchers, pilots, and crew. Meals were eaten together – the collective carried each other through the cold. The course: a 4.5 km loop, with quick access to the camp in case of a sudden change in wind direction, for safety reasons.
Unforgiving conditions
A polar day – bright around the clock, only the intensity of the sunlight varied. Daytime temperatures ranged from -15 to -20 °C, dropping to -30 °C at low altitudes. The wind made it brutally cold. The route was challenging: one side downhill, the other steeply uphill. Sweat loss despite the sub-zero temperatures – what leaked out froze. The outer layers of clothing became rigid. A setup that only works with a clear strategy.
- Strategy at -15 to -30 °C: Don't start too warm, avoid overheating; prioritize speed and efficiency.
- Traction is key: Rainer relies on Joe Nimble trail shoes with spikes/crampons for grip on ice and control in snow.
- Uphill on the icy track: Addict load distribution and ToePilot® support the big toe push-off – stable propulsion, less slippage.
- Downhill in snow: nmblaze eTPU cushioning works reliably, joints remain calmer despite the lack of rebound on icy sections.
- toefreedom fit: natural toe room for precise foot placement and secure changes of direction, even with stiff outer layers.
Rainer decided not to change his clothes for the entire run. He wore the same Joe Nimble Trail model with spikes the whole time. The reason: reliable grip, precise big-toe feedback, and consistent cushioning – even in falling temperatures.
Every minute in the warm tent, the layers thawed, making you wet – and outside, everything froze solid again immediately. Then there was the issue of nutrition: drinks froze solid – water, sports drink, cola – everything was ice. Thawing took time and increased dehydration. Changing clothes would have meant an additional 1-2 hours of lost time. Not an option!
Material selection like in Formula 1
As in motorsport, the choice of setup is crucial: traction before showmanship. Rainer relies on Joe Nimble boots – on his feet, the Trail Addict Pro R with spikes/crampons for uncompromising grip. The toefreedom® fit ensures a stable stance and clean push-off, ToePilot® directs power through the big toe, and the cushioning remains reliable even in cold conditions.
Uphill, he chose the ice track for efficiency – precise grip, clear propulsion; downhill, the snow track for control – smooth, secure, without any slips. Since ice offers hardly any natural rebound, a setup-reliable boot is all the more important.
His clothing remained functional and streamlined: layering without experimentation, wind protection on the outside, breathability on the inside – no need to stop to change. The socks handled heat and moisture management: close-fitting, blister-resistant, and proven in the cold. Combined with the wide fit, this resulted in a stable, pressure-free fit.
Thus, the system of shoe, socks, and spikes remained consistent – from the first lap to the last.
Race Summary: Cleverly Paced, Consistently Executed
The first 50 km were run together with a Chinese athlete, "a bit fast," but controlled – high cadence, short, compact stride, stable hips, and a tight arm stroke. Rainer carried gels and salt tablets close to his body in his jacket – energy bars were rock hard and unchewable. The aid station tent theoretically offered drinks, but in practice, it was blocks of ice.
Timing was everything: staying too long in the warmth meant getting wet immediately; going back into the wind resulted in a frostbitten shock. Deciding between efficiency and protection was part of the race. From kilometer 70 onward, Rainer ran alone, with a flat foot strike and short ground contact time on the ice, and a slightly longer, cushioned stride in the snow.
The sun was in a favorable position, morale rose, the weather became windier – but visibility remained clear. His gaze stayed 3-5 meters ahead, his breathing remained steady through the mask, and stops were kept to a minimum.
His body functioned well, and even the often tricky "toilet issue" was avoided. 9 hours, 55 minutes, 44 seconds – no stopping, no energy loss.
Conclusion: The Right Decision – and the Right Line
Switching from the North Pole plan to the Ice Ultra was ultimately the key to success. Decision, preparation, execution – and the right tool on his feet: Joe Nimble.
The Trail Addict Pro R with spikes delivered exactly what matters in Antarctica: reliable traction on ice, controlled stability in snow grooves, clear feedback with every step, and cushioning that remains predictable even in extreme cold.
No changes, no experiments – a consistent setup that supports pace and line. This is how 100 kilometers in Antarctica became not only possible, but Rainer's natural habitat: reduced to what counts – stride, breath, focus.
In the end, this image remains: a runner completing lap after lap in endless daylight – and a shoe that delivers until the 100-kilometer mark.
