The race was in its early stages but Michael Russell was convinced he couldn't go on. A cold front lashed the hills of remote northern Vietnam with icy rain and thick fog, turning the already rugged terrain into a treacherous morass of thick mud that enveloped his swelling ankles, stifling each step. Darkness and mist had covered the trail hours ago, and many more hours would pass before he walked the more than 100km that represented just the opening segment of an almost week-long course. He was beyond fatigue; every frayed muscle screamed at him to halt, to lie down right there in the muck and rest. The only thing that kept him going were his companions, who were every bit as exhausted - and the knowledge that if any one of them stopped, it would be a long time before someone came along to help them to their feet.
Vietnam's Lao Cai province is a long way from the usual haunts of the 36-year-old Hong Kong-based Australian, a director with property firm CB Richard Ellis, and the Racing the Planet: Vietnam event, a 250km trek through the badlands near the Chinese border, was far more gruelling than the casual hikes and rugby matches that represent his fitness regime.
It wasn't thrills or a burning urge to push his limits that took Russell to the Vietnamese highlands, but his two-year-old daughter, Isabella. The sores that dotted his feet at the end of each day on the trail were a constant reminder of her.
Shortly after her birth, Isabella was diagnosed with epidermolysis bullosa (EB), a rare genetic condition characterised by the presence of extremely fragile skin, which is prone to spontaneous blistering. More severe versions leave children almost permanently swathed in bandages and unable to tolerate even their parents' touch. Isabella has a milder form of EB, which will make swimming or competitive sports difficult but won't prevent her from leading a relatively normal life. Still, seeing her struggling to walk on red raw feet and having to regularly hold her down and lance her boils to ease infection convinced Russell he had to contribute whatever he could to the global effort to understand and treat EB.
When he heard about people tackling the Racing the Planet events to drum up funds for charity, his next move became obvious. Enlisting the support of co-workers Jennifer Hill and Jason Parry, Russell registered Team CBRE Blister Busters for the February race through Vietnam's scenic Sapa region. The money the team raised would go to DebRA, a Britain-based group advancing the cause of EB sufferers.
'I'd never done anything like it, or even camped out much before,' Russell says. 'I also have to admit that I felt really selfish; it's hard to weigh up what causes need the most help and you almost feel like you're taking money away from other charities.'
Despite these concerns, the response was overwhelming. Reaching out mainly to family, friends