The initial stop might be at the Salvation Army centre in Yau Ma Tei to donate the old clothes. There they receive another envelope of instructions, eventually leading them to Lamma Island, where they must complete a rock-climbing and abseiling exercise under the supervision of a qualified expert.

'The key is confidentiality,' said Ms Lee, who goes to great lengths to make sure every programme is different. 'The more we keep things secret, the more the participants will learn about how to adapt to new situations.'

The programme was introduced in April last year, initially for about 20 senior managers, and is gradually being expanded to include support staff and more junior personnel.

Ms Lee said the primary objective was to strengthen team spirit, but the exercises also gave staff the opportunity to challenge themselves in new ways and to confront deep-seated fears.

'The different tests combine both physical and mental aspects, and give staff something to work out in groups,' she said. 'The tasks may have no relation to their work, but they teach them how to solve problems and co-operate more closely.'

To inject a sense of urgency, the teams must race each other and, to test their ingenuity, some clues are deliberately confusing. A map of Sai Kung, for instance, may have no bearing on the actual route required to get to the next stop.

To ensure that no one tries to skip any required steps, certain receipts or proofs have to be collected along the way. For those who encounter difficulties, there is an 'emergency' envelope to get them back on track. But opening this envelope automatically means points deducted from the final score.

During the race, each team may have to buy food for dinner and later cook it over an open fire at a campsite. The second day is likely to include more outdoor activities such as raft building or jumping from a height into open water. The mental part of the challenge comes in the form of IQ tests or puzzles, the results of which go towards the team's scores. Taken together, all the different elements promote teamwork, test individual limits and encourage self-awareness.

Ms Lee said one recent exercise required participants to climb one of the highest hills on Lantau. At the top, they were asked to sit and think about personal goals and areas where the company could do better, and to jot down all their ideas in a notebook.

'Overall, the response has been very good,' Ms Lee said. 'The programme is hard, but it gives everyone a chance to overcome weaknesses and build strengths.' She said the immediately visible benefits included improved communication in the workplace and a greater willingness for colleagues to help each other out. That was vital, since the efficient running of the firm's chain of seven fitness clubs in Hong Kong often came down to dealing with 'human issues' rather than sorting out specific technical problems.

Ms Lee has tackled even the scariest challenges herself.

'Before the abseiling, I was almost crying. But people really encouraged me, telling me not to look down - and I made it.'