We are happy to announce that all trial registrations will now be issued DOIs (digital object identifiers). For more information, see here.
The Three Cs - Increasing Physical Activity
Last registered on December 02, 2019


Trial Information
General Information
The Three Cs - Increasing Physical Activity
Initial registration date
March 04, 2019
Last updated
December 02, 2019 9:23 AM EST

This section is unavailable to the public. Use the button below to request access to this information.

Request Information
Primary Investigator
University of Aberdeen
Other Primary Investigator(s)
Additional Trial Information
On going
Start date
End date
Secondary IDs
Physical inactivity is one of the four major risk factors for non-communicable diseases (WHO 2016). Decisions about engaging in physical activity involve making trade-offs between immediate costs and future benefits suggesting that time preference (how present or future oriented an individual is) and present bias (the enhanced significance an individual attaches to immediate outcomes) may play a part in how these decisions are made. Despite demonstrated correlational associations between physical activity and time preference and present bias, to date, time preference and present bias have not been taken into account when designing interventions to increase physical activity. Within economics the quasi-hyperbolic model (Laibson 1997) is currently used to model such intertemporal decision making. From examining the quasi-hyperbolic model it can be seen that the individual’s decision to engage in physical activity depends on the temporally proximal costs and the temporally distant benefits of that activity, how much they discount the temporally distant benefits and how present biased they are when the time to be active becomes immediate. This suggests that an effective intervention should aim to increase the salience of future benefits and counteract present bias. Increasing the salience of temporally distant benefits might be achieved by getting the individual to consider the future consequences of their actions and connect to their future-self. Present bias is often assumed to involve temptation and self-control. Commitment contracts (paying a forfeit for failing to follow through with plans) are often regarded as a method of overcoming temptation and therefore counteracting present bias. This leads to the conclusion that an effective intervention could aim to (a) increase the salience of temporally distant benefits of activity by considering future consequences of current inactivity and connecting to one’s future-self and (b) counteract the temptation component of present bias by applying commitment. This study seeks to develop, and then test the effectiveness of one such intervention which has the potential to be inexpensive and easy to administer and could therefore provide a valuable addition to measures being used to counteract the physical inactivity crisis.
External Link(s)
Registration Citation
Thomas, Uma. 2019. "The Three Cs - Increasing Physical Activity." AEA RCT Registry. December 02. https://doi.org/10.1257/rct.3967-1.1.
Former Citation
Thomas, Uma. 2019. "The Three Cs - Increasing Physical Activity." AEA RCT Registry. December 02. https://www.socialscienceregistry.org/trials/3967/history/57961.
Sponsors & Partners

There are documents in this trial unavailable to the public. Use the button below to request access to this information.

Request Information
Experimental Details
Intervention One - Consideration & Connection. This is designed to increase the salience of an individual’s beliefs about the future benefits of physical activity and to improve their connection to their future-self.

Intervention Two - Consideration & Connection & Commitment Group (C&C&C). This intervention combines the Consideration and Connection intervention with the Commitment task.
Intervention Start Date
Intervention End Date
Primary Outcomes
Primary Outcomes (end points)
The primary outcome is increase in step count over baseline at four and eight weeks.
Primary Outcomes (explanation)
Secondary Outcomes
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
Experimental Design
Experimental Design
A three (equal) arm randomised control trial comparing the effectiveness of Consideration & Connection (C&C) and Consideration, Connection & Commitment (C&C&C) compared to a control group.
Experimental Design Details
Not available
Randomization Method
Randomisation carried out by Qualtrics software.
Randomization Unit
Was the treatment clustered?
Experiment Characteristics
Sample size: planned number of clusters
Sample size: planned number of observations
100 individuals
Sample size (or number of clusters) by treatment arms
33 individuals per treatment arm
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB Name
University of Aberdeen College of Life Sciences and Medicine Ethics Review Board
IRB Approval Date
IRB Approval Number