Participants will conduct the intervention in groups under the supervision of a professional fitness trainer.

Participants will conduct the intervention individually, without the supervision of a professional fitness trainer

No intervention will be given to the control group.

Group exercise interventions tended to be systematic and supervised by professionals. The current intervention is proposing to conduct a randomized control trial that is not only examining the nature of walking on older adults' well-being but also involving the elements of group-based and professional supervision intervention, aiming at comparing with the individual-based intervention without professional supervision. Qualified professional fitness trainers (1 male and 1 female separately for male and female groups, respectively) will be involved in the group-based intervention programs in order to provide appropriate guidance and supervision to the participants. Whereas, the non-supervised individual-based intervention will be conducted by a research assistant (males and females) to ensure the attendance and general safety, but without providing professional advice or supervision.

The Short Form-36 (SF-36) is a widely used health survey questionnaire, especially for older adults to assess the health-related quality of life (HRQoL). The higher the scores mean a higher level of quality of life.

Physical Performance Test (PPT) is one of the tools which is used to assess the level of frailty. For our research we will use 9 item scale that includes 9 standardized tasks such as writing a sentence, simulated eating, turning 360 degrees, putting on and removing a jacket, lifting a book and putting it on a shelf, picking up a penny from the floor, a 50-foot walk test, and climbing stairs (scored as two items) (Reuben and Siu, 1990). The score range of each task is 0-4 and for 9 items it will be 36. A higher score indicates better performance (Villareal et al., 2017).

The Mini-mental state examination (MMSE) is the most commonly used method to measure the level of cognitive impairment, especially in older adults. The score of Mini-mental state examination is calculated on a scale of 0-30 where score 24 or above is usually considered as the normal cognitive status or no cognitive impairment of the individual. The overall scorings are Severe cognitive impairment (0-17), Mild cognitive impairment (18-23) and No cognitive impairment (24-30).

The walking effects on participants' health parameters, namely body composition, will be assessed. The body composition will be assessed by Tanita MC780U (Tanita Corporation, 2020), by which the percent body fat and lean body mass of participants will be recorded. The body mass index (BMI) using participants' heights and weights (measured by the RA) will also be recorded.