Their tutor, Wendy Liu Wai-hing, hopes the students will learn to co-operate.

'The teams will have to finish together. So they have to help each other and can't let anyone fall behind,' Ms Liu said.

'These students all have different characters and some of them have had problems working as a team. We have had three training sessions and I can see improvements in them.'

Now in its 12th year, the annual event raises money for environmental group Green Power.

Funds raised will be spent on environmental education to build a greener future for Hong Kong.

The participating teams are expected to complete the 50km course within 18 hours.

Angel Yip Hiu-ching, a Form Four student at Valtorta College, said the training strengthened her stamina. 'I have never gone hiking and it was pretty tough for me when we first started training,' said the 15-year-old, who has been running for an hour every day to prepare for tomorrow's event.

'There are two boys and two girls on my team. The boys always blamed us for slowing them down.

'But after awhile, they seemed to understand our situation and cared more about our feelings. They now help us keep our pace.'

Roger Wong Ming-hang, from Ling Liang Church MH Lau Secondary School, has learned how to work as a team.

'I used to be very self-centred and selfish ... [and] didn't really consider other people's feelings,' said the fourth former.

'But I have changed over the past month. I've learned how to support and help others.

'And hiking is a good sport to get fit. The scenery is also very beautiful, especially along Lung Chek [Dragon's Back] near Shek O.'

With the support of family and teachers, each student has so far raised at least $700 for Green Power.

Ms Liu said the students aimed to finish the course within 10 hours.