The control group will receive a "usual care" educational programme at baseline created by the Singapore Health Promotion Board. This guide describes the importance of physical activity and illustrates one possible physical activity programme. It also discusses strategies for adopting a healthy lifestyle. They will not receive the Fitbit Zip wireless pedometer from the study team. However, they will receive $4 per week, regardless of physical activity levels.

This group receives the Fitbit Zip, and access to the Fitbit website. Fitbit Zip counts the number of steps walked, calories burned, and distance travelled. Participants can set goals for their physical activity levels, and will have access to personalised feedback from Fitbit. This group will also receive $4 per week, regardless of physical activity levels.

This group receives the Fitbit Zip and the opportunity to earn money each week based on the number of steps logged on the pedometer during that week. We will offer the following incentive schedule:

• $0 SGD for less than 50,000 steps during the week
• $15 SGD for 50,000 - 69,999 steps during the week (max of 20,000 steps per day)
• $30 SGD for 70,000 or more steps during the week (max of 20,000 steps per day) Participants will receive monthly payments in cash after their physical activity is confirmed. The incentive will be calculated separately for each week of the 6-month incentive programme.

Fitbit Zip is a wireless pedometer that tracks steps of participants, and will be offered in conjunction with a tailored website with customized information for participants, employers, and/or charities.

MVPA bouts are defined as the total number of minutes during each 1-week assessment period in which moderate or vigorous activity of at least 8 of 10 consecutive minutes are reached. This will be assessed via the Actigraph GT3XE-Plus Triaxial Activity Monitor.

We will measure "MVPA bouts" at baseline, 6, and 12 months. We hypothesize that participants in the Programme Only, and Incentive groups record more "MVPA bouts" at 6 months compared to baseline. Furthermore, participants in the Incentive groups will record more "MVPA bouts" at 6 months compared to the Control and Programme only groups.

We also measure "MVPA bouts" for all participants at 12 months. We do so to test if the "MVPA bouts" measured at month 6, can be sustained at month 12 when incentives are no longer being provided.

VO2Max is one of the major parameters to evaluate health and fitness of the cardiovascular system and is widely used for health promotion purposes. VO2Max will also be assessed via the Non Exercise Fitness Test (NEFT); NEFT predicts VO2max based on age, gender, BMI, resting heart rate and self-reported physical activities.