The 2026 Hong Kong 100 trail running race (commonly known as HK100) will get underway next Thursday; among all categories, the toughest is undoubtedly The GRAND SAM Grand Slam category.

Participants in this category will run across three consecutive days, taking part in the 33, 50 and 100 km races, with a cumulative distance 173.73 km, total ascent 8502 m, total descent 8068 m.

From the 10-person field at its inception in 2023, participation has surged to 250 for this edition. Last year's male and female champions, Wu Yongbo (total finishing time 20:30:16) and Zhao Fen(total finishing time 25:30:31) are returning to the Grand Slam category to defend their titles.

In the men's field, Anta Champion Elite athlete Wu Yongbo will be racing on home turf, and his clear objective is to successfully defend his title. He officially joined the Anta Champion Elite team after clinching last year's HK100 Grand Slam, and his recent form and training preparation have been excellent.

But he will have to contend with challenges from Zhao Jiaju, Zhang Zhenlong, Xiong Zhengqiang, as well as two-time Grand Slam winner Liang Disi and Sherpa Sangé . Judging by recent race form and ITRA points, at least six to eight athletes could enter the title mix, and it's especially intriguing to see what tactics the aggressive Zhao Jiaju will adopt.

In the women's field, defending champion Zhao Fen returns to defend her crown, with endurance specialists Deng Ronghua and Chen Rongrong posing the strongest threats. Particularly with Chen Rongrong's consistency over long distances, many male competitors wouldn't be confident of a guaranteed win against her.

One point worth noting in particular is that Grand Slam category athletes start at the same time as single-category athletes, so it's also worth watching where those athletes end up in the single-category standings. After racing two days in a row, will Wu Yongbo and Zhao Jiaju still have a chance to break into the top ten in the 100 km race?