Sarah Pemberton is embarking on the 160km (100-mile) Ultra Trail Mount Fuji (UTMF) on Friday and, despite an injury stopping her from training properly, she is confident she has the fortitude to finish.

In February, Pemberton took part in the notorious 298km Hong Kong Four Trails Ultra Challenge (HK4TUC) and although she did not finish, she made it past 200km and is drawing strength from her feat.

“I’m relying on the endurance I’ve built up, because I haven’t been able to do long training runs,” she said. “But also, that mental side, having run much farther than 160km now, knowing I can keep going.”

This will be her fifth 100-miler, but Pemberton is not overly confident at the distance. She also won a place at the famous Ultra Trail de Mont Blanc in France this August, where they have various distances, including 100km and 100 miles, to choose from.

“I was torn because I really love the 100km,” she said, but picked the 100-miler anyway. “I’m getting confident at 100km in a way I don’t feel confident yet over 100 miles.”

“Every time I have done a 100-miler, there has been at least one moment I thought I’m going to give up,” Pemberton said, adding she once even called the race director asking to be picked up, but was convinced to sleep for an hour and continue.

“I now know that this [UTMF] will be tough, but if I rest and eat the suffering will pass.”

The UTMF is Pemberton’s first race since the HK4TUC.

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“I don’t think I’ve totally made my peace with it yet, I can’t view it positively,” she said. “I know I should be proud, it is 50km further than I’ve ever run. [But] if I wanted a big redemption race, a cathartic run, I would be doing something I could really push and train properly for.”

The HK4TUC has fewer than 30 participants, a stark contrast to the popular UTMF with thousands of runners.

“It is my first race that is really big, so there will be a lot of people on the trails. It won’t be lonely, but maybe it will be busy in a negative way, too,” she said, adding she has not examined the course in detail and hops ignorance will be bliss.

“I don’t really know what the trails look like, beyond the course map and where the climbs are.”