The majority of the South African gym population don’t visit the gym enough to reap the
health rewards. This is not only detrimental for the individual, but also the country as a
whole as it impacts the economy. Numerous information driven interventions have been
deployed in the hope of motivating people to stay active, but with limited success. Dynamic
Inconsistency could explain this type of behaviour, as it suggests that choosing every day
to do what you decided to do at a point in time (like visiting the gym everyday) is the
biggest stumbling block in following through on a decision. Why? Because making a
rational decision in the face of temptation such as sleeping in instead of going to gym, is
difficult. An approach subsequently had to be implemented that looked beyond the familiar
cognitive approach and searched for new ways to influence healthy choices. A
Behavioural Economics theory called Communication Framing was therefore deployed as
a potential behaviour modifier.
The purpose of this study was subsequently twofold. Firstly, it was to understand whether
infrequent gym visitors (those who visited the gym less than 11 times a month) did so
because of Dynamic Inconsistent decisions. Secondly, it was to see if positive or negative
goal-framed messages would influence those that did fall into the Dynamic Inconsistency
trap to exercise less than 12 times a month.
A multi-method quantitative research approach was used due to the nature of the study.
Before Communication Framing could be tested as a method to influence members to visit
the gym more often, those who were influenced by Dynamic Inconsistency had to be
identified. Thus the research had to be divided into two phases.
Phase One made use of the newly developed Exercise Consistency Questionnaire, which
aimed to discover those who made gym, related Dynamic Inconsistent decisions. A total of
623 respondents answered the questionnaire in some shape or form; however, some had
to be excluded as they did not comply with the sample criteria. A workable sample of 446
individuals, those who exercised less than 11 times a month, was therefore identified.
Most respondents across the two groups had some degree of Dynamic Inconsistency, thus
succumbed to the temptation. With the help of statistical analysis, a slight negative
correlation was found across both groups, suggesting a slight tendency towards an
“exercise-increase/ impulsivity-decrease” relationship. The difference between the two,
however, was in the degree of this relationship. Those who exercised less than 11 times a
month had a much higher Dynamic Inconsistency score than those who exercised more
than 12 times a month. The conclusion that people who exercised less were slightly more
likely to fall into the temptation-trap than those who exercised more frequently was
therefore made and proved why this group were in need of an intervention.
Those identified became the population for Phase Two and were randomly divided into
three groups. One group receive a negative goal-framed message, the second group a
positive goal-framed-message and the third none as it became the control.
The 446 respondents subsequently became the sample for Phase Two. Descriptive and
inferential statistics were used to determine if any of the interventions succeeded in getting
people to exercise more than 11 times a month. An ANOVA test was performed and
indicated that the changes within the groups were more likely due to chance as appose to
the message interventions. Further analyses in the form of scatterplots and frequency
distribution suggested that the messages did have an effect, but that it performed different
The positive goal-framed messages had an effect on those who did not exercise at all. It
moved them into becoming active. The negative goal-framed message on the other hand
affected those who already exercised and got them to exercise slightly more often. Neither
message however delivered on the goal of getting people to exercise more than 12 times a
The effects however were minimal and only came to the fore once an in-depth analysis
was done. Results should therefore be seen more as an indication rather than fact.
Additional research that considers the numerous weaknesses identified in this study,
should be done in order to prove the results accurate.
Dissertation (MPhil)--University of Pretoria, 2015.