for people ages 60 years and up (full criteria)
Healthy Volunteers
healthy people welcome
study started
estimated completion
Principal Investigator
by Anya Samek



Inactivity is the fourth leading risk factor for global mortality, leading to chronic diseases. Much of the world's population is inactive, and older adults are at highest risk. Incentive-based interventions show promise for improving activity levels. The investigators propose to conduct a study to evaluate the impact of incentives on physical activity of older adults (60+). Half the participants will receive additional incentives for walking throughout the study. Their step count and physical/mental health will be compared to a control group. The investigators will track the physical activity of participants using Fitbits and will encourage physical activity through making meal donations on behalf of participants (prosocial incentives) and giving them gift cards that can be redeemed at local businesses (personal incentives). Physical and mental health before and after the study will also be assessed using a written survey.

Official Title

Incentives for Physical Activity - An RCT With Older Adults


Inactivity is the fourth leading risk factor for global mortality, leading to chronic diseases (e.g., heart disease, diabetes) and contributing to the obesity epidemic. Much of the world's population is inactive and older adults are at highest risk. Inactivity in older adults is linked to age-related diseases and cognitive decline. Inactivity also imposes social costs through increased medical expenses, which are already high among the growing older adult population in the US.

Incentive-based interventions have gained popularity among behavioral scientists and policymakers as a tool for improving health-related behaviors. But there are drawbacks - first, monetary incentives are often not cost-effective, and therefore scalability is limited. Second, behaviors often return to baseline when monetary incentives are removed, i.e., healthy habits are hard to maintain when incentives are limited in duration. Third, there is a concern that monetary incentives crowd out intrinsic motivation to engage in health-promoting behaviors.

In light of the limited success of incentive-based behavior change programs, the investigators propose to design and evaluate alternative incentives that address these challenges of scalability, habit formation and crowd-out. The investigators will aim to encourage physical activity through alternative incentives - by making a meal donations on behalf of participants (prosocial incentives) and give participants monetary incentives that will be loaded onto a gift card (personal incentives). Both types of incentives have underpinnings in behavioral economics.

Meal donations harness prosocial preferences, which may be more powerful and less likely to reduce intrinsic motivation than equivalent monetary incentives. Gift cards that can be redeemed at businesses harness "mental accounting" - the idea that incentives are more valuable when targeted to higher-valued accounts like eating at restaurants.

The overall aim is to evaluate the impact of alternative incentives on step count of older adults in the short-term and long-term. Exploratory analysis will also evaluate the impact on physical and mental health. The investigators will recruit 200 older adults and randomize half of them to receive additional prosocial and personal incentives for their walking behavior. The other half will not receive these incentives. The investigators will track step count of these two groups for 7 weeks using a Fitbit device. Under the treatment functionality, participants accrue a meal donation and a point for Feeding America for each day that they meet the step goal.

The investigators plan to recruit older adults ages 60+ at grocery stores and other locations around San Diego, CA. Recruitment will be on a rolling basis. PI Samek has recruited participants at grocery stores in prior studies, hence the investigators believe this is feasible. Participation will be limited to individuals who own a smart phone (61% of older adults in the US own a smart phone, and the investigators expect this number to grow as the population ages). Studies have shown that older adults are open to using app-based technologies, for example older adults are accepting of mindfulness apps.

The research team will be given access to participants' Fitbit data through Fitabase, a research platform that collects data from internet connected consumer activity devices. The investigators identified 6,000 steps as an appropriate goal as studies show older adults walk 4,000 steps on average. For the treatment group, meals will be donated by the research team to Feeding America for each day they meet the step goal of 6,000 steps. They will also receive money every week in the form of a gift card if they meet the step goal of 6,000 steps on at least 3 out of 7 days in that week. Participants can redeem their gift cards (ClinCard) in stores or online, where Visa debit cards are accepted. The control group will not receive these incentives for their walking behavior, but their daily step count data will be collected.

Participants will receive a Fitbit upon enrollment. The investigators will collect their physical activity data for 1 week, as their baseline physical activity. After 1 week, individuals will be randomized to the treatment group, which receives the incentives for 6 weeks, or to a control group which does not.

To reduce attrition, the investigators will encourage participants to complete the assessment in the beginning of the study and at the end of week 7. The investigators incentivize participation from both groups. By monetarily compensating them at sign-up and at the week 7 assessment. Further, participants in both groups will receive compensation for wearing the Fitbit device at least 3 days a week and greater compensation for wearing it every day of the week.


Physical Activity, Incentives for Physical Activity


You can join if…

Open to people ages 60 years and up

  • 60 years old or older
  • own a smartphone
  • can walk independently

You CAN'T join if...

  • below 60 years
  • does not own a smartphone
  • unable to walk independently

Lead Scientist at UCSD

  • Anya Samek
    Associate Professor, Rady School of Management, Vc-academic Affairs


not yet accepting patients
Start Date
Completion Date
University of California, San Diego
Study Type
Expecting 200 study participants
Last Updated