This study aims to determine, using a randomized trial with two parallel arms, whether hedonic rewards (Arm 1) can be more effective than their cash equivalent (Arm 2) in motivating participants to meet step goals.

The evidence is overwhelming that sustained physical activity reduces risks for non-communicable diseases, increases longevity, and reduces medical costs. Yet, the rates of physical activity have been steadily decreasing such that physical inactivity is now the fourth leading cause of death worldwide. In Singapore, 33% of adults are insufficiently active despite Singapore being a highly walkable city with numerous subsidized community-based physical activity programs. A review of the literature shows that, to date, no study has directly compared cash versus hedonic rewards for health behavior change despite theory suggesting hedonic rewards may work better. Furthermore, hedonic rewards can often be purchased at lower cost than their cash equivalent. This makes hedonic rewards potentially more cost-effective if they are proven to be at least as effective at increasing positive behavior change compared to giving the same value in cash.

Thus, we aim to determine, using a randomized trial with two parallel arms, whether hedonic rewards (Arm 1) can be more effective than their cash equivalent (Arm 2) in promoting increases in physical activity, assessed via step counts measured by a Fitbit physical activity tracker, during a 4-calendar month intervention. We hypothesize that the average proportion of months meeting the incentivized step target across participants will be greater for those in the hedonic incentive arm as compared to those in the cash incentive arm (primary outcome).

Inclusion Criteria:

• Aged between 21 to 70 years inclusive.
• Singapore resident (residing in Singapore during the study period [up to 5 months])
• English-speaking and English literate
• Smartphone-literate

Exclusion Criteria:

• Pregnant or lactating
• Unable to walk up 10 steps (individual steps, not floors) without stopping
• Currently on doctor's advice against engaging in moderate-to-vigorous physical activity (i.e., brisk walking or more intense).
• Currently have a condition(s) that restricts engaging in moderate-to-vigorous physical activity (i.e., brisk walking or more intense).
• Unwilling to be randomized into study arms
• Unwilling to use a Fitbit for the study period (up to 5 calendar months)
• Unwilling to pay the $20 enrolment fee
• Does not complete the Consent Form
• Refuses to give consent to participate in the study