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Email reminders and gym attendance
Last registered on December 14, 2016

Pre-Trial

Trial Information
General Information
Title
Email reminders and gym attendance
RCT ID
AEARCTR-0001847
Initial registration date
December 14, 2016
Last updated
December 14, 2016 5:31 AM EST
Location(s)
Region
Primary Investigator
Affiliation
Vrije Universiteit Amsterdam
Other Primary Investigator(s)
PI Affiliation
University of Gothenburg
Additional Trial Information
Status
In development
Start date
2016-12-14
End date
2017-08-31
Secondary IDs
Abstract
We investigate whether regular email reminders can stimulate gym attendance. We will send out weekly emails to a random sample of gym members of a large gym facility (with multiple locations) during a period of 3 months. In addition we collect a measure of interest in email reminders prior to the intervention. We investigate the effect separately for those that do and those that do not indicate interest in reminders. We will collect detailed attendance data during the intervention period, as well as during three subsequent months to investigate long run effects (habit formation).
External Link(s)
Registration Citation
Citation
Habla, Wolfgang and Paul Muller. 2016. "Email reminders and gym attendance." AEA RCT Registry. December 14. https://doi.org/10.1257/rct.1847-1.0.
Former Citation
Habla, Wolfgang, Paul Muller and Paul Muller. 2016. "Email reminders and gym attendance." AEA RCT Registry. December 14. http://www.socialscienceregistry.org/trials/1847/history/12401.
Experimental Details
Interventions
Intervention(s)
Intervention Start Date
2017-01-08
Intervention End Date
2017-04-01
Primary Outcomes
Primary Outcomes (end points)
- Gym attendance (daily)
- Type of attendance (free training, or group classes)
- Signing up to classes/cancelling of class subscription
Primary Outcomes (explanation)
Secondary Outcomes
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
Experimental Design
Experimental Design
The sample contains all individuals that bought a 12 months gym membership between July 1 and December 1 2016. We observe whether these individuals had a previous membership in the preceding 6 months. Both new and existing members will be included in the analysis.

All of these participants will receive an email in the middle of December, asking them whether they think email reminders could be a useful mechanism to facilitate reaching ones exercising goal. The response to this email allows us to distinguish between individuals that do and those that do not expect to benefit from reminders.

Starting from the beginning of January, 50% of the participants will receive weekly email reminders that contains short messages regarding gym attendance. Participants can at any time unsubscribe if they do not wish to receive any further messages. The reminders are sent during three months. The control group (the other 50%) does not receive any email reminders during this period, although they will receive a newsletter that is sent by the Gym approximately once every 6 weeks.
Experimental Design Details
Randomization Method
Randomization will be performed in two separate sub-samples: the group that indicated interest in email reminders, and the group that did not indicate interest in email reminders. In both groups 50% will be assigned to the treatment of email reminders. Randomization will be done by computer.
Randomization Unit
Individual
Was the treatment clustered?
No
Experiment Characteristics
Sample size: planned number of clusters
2500 individuals
Sample size: planned number of observations
2500 individuals
Sample size (or number of clusters) by treatment arms
1250 individuals in treatment group
1250 individuals in control group
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB
INSTITUTIONAL REVIEW BOARDS (IRBs)
IRB Name
Ethical committee department of Economics
IRB Approval Date
2016-12-09
IRB Approval Number
n/a
Post-Trial
Post Trial Information
Study Withdrawal
Intervention
Is the intervention completed?
No
Is data collection complete?
Data Publication
Data Publication
Is public data available?
No
Program Files
Program Files
Reports, Papers & Other Materials
Relevant Paper(s)
REPORTS & OTHER MATERIALS