This project aims to investigate the effects of an individualized exercise programme with and without BCE strategies for community-dwelling frail older people with general fatigue, so as to reduce their fatigue and improve their physical endurance, exercise self-efficacy, and habitual physical activity, while reducing their symptoms of frailty.

Twelve district community health centres will be randomized to one of the three study groups: the combined (COMB) group, receiving the 16-week combined intervention consisting of individualized exercise training and Behavioural Change Enhancement programmes plus two booster sessions at 2 and 6 months after the programme; the exercise (EXER) group, receiving exercise training and health talks only; or the control group, receiving health talks only. Participants from each centre will be placed in their centre's corresponding group.

It is hypothesized that the COMB group will achieve a significantly greater reduction in fatigue and a greater improvement in their physical endurance, exercise self-efficacy, and habitual physical activity, and a significantly greater reduction in their frailty symptoms, when compared with the EXER and control groups at 1 week and 6 and 12 months after completing the interventions.

All twelve community centres, which provide similar types of community care and social support services for community-dwelling older people, have been invited by a convenience method to work as collaborators in this study. The target population of this study are community-dwelling frail older people with general fatigue with a nonspecific cause who will be recruited through the community centres. Using computer-generated random numbers, a biostatistician not affiliated with this study will randomize the centres into either: control, EXER, or COMB. The number of participants recruited in each centre will be in proportion to the size of the centre.

Participants allocated to the COMB group will receive a 16-week programme with a combination of the BCE programme and exercise training. The BCE programme is designed based on the Health Action Process Approach (HAPA) model and was piloted by the principal investigator, which aims to motivate the participants to develop the intention to actively manage their fatigue; and to encourage them to gradually exceed the perceived limits of their energy and to recondition their bodies by participating in exercise according to their individual exercise regimens. The BCE programme consists of three phases (the goal initiation, plan formulation and action execution) with 6 face-to-face 1-hour sessions plus two booster BCE sessions at 2 and 6 months after the programme.

For the exercise training, a weekly 45-60 minute centre-based exercise programme, which is designed according to the American Heart Association's recommendations on exercise for older people will be arranged from weeks 4-16 during the execution phase. The exercise sessions consist of balance training, resistance exercises, and aerobic training. All participants will receive circuit training with set exercises, but the dosage of different components will be tailor-made for each participant by a physiotherapist after having their physical conditions examined.

The EXER group will receive a 16-week programme with a combination of exercise training and centre-based health talks on the management of different health issues with the exception of fatigue.

The control group will attend centre-based health talks only.

The number and timing of the health talks for the other two groups will be similar to those in the BCE sessions.

Inclusion Criteria:

• community-dwelling older people aged > 70 years;
• able to communicate in Cantonese to ensure that they understand our instructions;
• able to walk with or without an assistive device and able to complete the Time Up and Go (TUG) test with no specific cutoff point to ensure that their mobility and balance is good enough to join the exercise training; and
• in a frail state with exhaustion as determined using the Fried Frailty Index (FFI), including: i) an unintentional loss of 10% of body weight in the past year; ii) exhaustion: by answering 'Yes' to either 'I felt that everything I did was an effort', or 'I could not get going in the last week'; iii) a slow walk time: with an average walking speed in the lowest quintile stratified by median body height; iv) reduced grip strength: with maximal grip strength in the lowest quintile stratified by body mass index quartile; and v) the Physical Activity Scale for the Elderly-Chinese (PASE-C) score in the lowest quintile (i.e., < 30 for men and < 27.7 for women). The presence of > 3 items indicates frailty, and one criterion indicates that they suffer from exhaustion.

Exclusion Criteria: are older people who:

• are suffering from any disease in which fatigue is a dominant symptom (such as neurodegenerative diseases, cancer, and end-stage renal failure cachexia cases;
• have been hospitalized for > 5 days in the preceding 3 months, which may lead to muscle wasting due to recent bed rest or reduced activity levels during hospitalization;
• underwent major surgery (such as total joint replacement, major abdominal surgeries) during the last 6 months;
• are confined to bed or restricted by the permanent use of a wheelchair;
• report that they regularly perform moderately intense exercise (such as hiking, Tai Chi) for > 3 hours per week;
• are terminally ill;
• have been diagnosed with major depression entailing frequent adjustments of their antidepressants to control unstable depressive moods. The criteria were chosen to avoid recruiting people with depression-induced fatigue. However, a consistent feeling of fatigue may manifest as a depressed mood. Thus, the participants' mood will be assessed using the Chinese-Geriatric Depression Scale (C-GDS).

For confidentiality, the data will be kept anonymous and the names of all participants will be replaced by reference codes. The data collected will be kept in a locked place and electronic versions will be encrypted, and only be accessible by the researchers. All data will be destroyed within 3 years after the completion of this research.

An independent assessor who is blinded to the group allocations will assess the participants' outcomes.