Keywords Acceptance and commitment therapy .
Implementation intentions . Exercise . Enjoyment
Exercising has an important role in the prevention and management
of many non-communicable diseases, including cardiovascular
diseases, diabetes, obesity, and some types of cancer
(Warburton et al. 2006). Despite the numerous health benefits
of regular exercise, less than 5 % of American (Troiano
et al. 2008; Tudor-Lock et al. 2010), and Canadian (Colley
et al. 2011) adults engage in the government recommended 30
or more minutes of at least moderate-intensity physical activity
on 5 to 7 days per week. Randomized controlled trials
targeting the adoption and maintenance of physical activity
in healthy (e.g., Carr et al. 2013; Dewar et al. 2014) and
clinical (e.g., Ang et al. 2011; Dewar et al. 2014) adult populations
demonstrate limited effectiveness in improving exercise
adherence. Specifically, nearly half of individuals who
begin an exercise program drop out within 6-months
(Dishman 1991; Marcus et al. 2000). Numerous barriers to
physical activity have been identified including, undesirable
weather, feeling tired, family needs, lack of time, perceived
financial cost, and lack of enjoyment (e.g., Ary et al. 1986;
Annesi 2004; Butryn et al. 2011; Johnson et al. 1990; Salmon
et al. 2003). Consequently, there is an ongoing need to design
interventions that target the wide-ranging barriers to physical
activity participation, thereby offering personalized methods
to promote long-term physical activity adherence.
Action planning, or implementation intentions, (BélangerGravel
et al. 2013; Gollwitzer 1999) is one avenue that can
have the potential to promote exercise behavior and adherence.
Namely, implementation intentions are concrete plans
that specify in an if-then format when, where, and how a
person intends to carry out an activity (Gollwitzer 1999). Implementation
intentions can help individuals who intend to
pursue a goal and are in the action-planning (volitional) phase
(Schwarzer 2001) with regards to reaching and maintaining
their goals (Bélanger-Gravel et al. 2013). Specifically, implementation
intentions create contingencies between a cue in the
environment (e.g., if ‘it is 5 pm after work’) and the goaldirected
behavior (e.g., then ‘I will go to the gym’). Implementation
intentions are highly effective in promoting healthenhancing
behaviors (e.g., medication adherence, physical activity),
as summarized in a meta-analysis of 94 studies that
produced an average effect size of 0.65 (Cohen’s d; Gollwitzer
and Sheeran 2006). To date, compared to other cognitivebehavioral
interventions (e.g., self-monitoring), implementation
intentions remain the most effective strategy in increasing
physical activity, demonstrating small to moderate effect size
on physical activity behavior immediately post-intervention
(i.e., standard mean difference (SMD)=0.31) and at nocontact
follow-up periods of approximately 11 weeks
(SMD=0.24; Bélanger-Gravel et al. 2013). Provided that implementation
intentions address only one factor (i.e., planning)
of physical activity adoption and maintenance, other
barriers to exercise-related maintenance may be better addressed
by alternative interventions. Particularly, acceptance
and commitment therapy (ACT), a form of cognitivebehavioral
psychotherapy (Hayes et al. 1999), is receiving
increasing support in the literature as an effective intervention
for improving acute exercise tolerance (Ivanova et al. 2015),
as well as short-term (i.e., 5-weeks) physical activity adherence
(e.g., Butryn et al. 2011). A core assumption of ACT is
that negative and unpleasant feelings and experiences are neither
good nor bad, but rather a facet of human life (Hayes et al.
1999). Accordingly, using acceptance-based techniques to
pursue physical activity goals focus on increasing an individuals’
willingness to experience aversive feelings, thoughts,
and sensations (e.g., perceived exertion, fatigue) without trying
to change or eliminate them (Butryn et al. 2011; Marcks
and Woods 2005). ACT techniques, therefore, may be one
means to provide resource for novice exercisers to improve
adherence through enhancing their coping abilities with adverse
physical demands during exercise (e.g., symptoms of
discomfort, fatigue, breathlessness). Indeed, a meta-analysis
by Kohl et al. (2013) found that acceptance strategies (such as
ACT) are more effective than regulation strategies (such as
suppression and distraction) in increasing pain tolerance. In
regards to the practical implications of ACT-based techniques
on improving physical activity adherence, Butryn et al. (2011)
implemented an ACT intervention (i.e., two 2-h group sessions),
which trained participants in mindfulness, clarifying
physical activity values, and willingness to experience distress
in the services of those values. Participants in the ACT condition
as compared to an education-only control condition,
showed more frequent self-reported physical activity (number
of days per week) at 5-weeks post-intervention, but with no
significant differences at 8-weeks post-intervention. Thereby,
ACT techniques may show some promise in initially increasing
exercise behavior, but the long-term impact (e.g.,
6 months) of using ACT techniques to increase exercise behavior
requires additional research.
Furthermore, our team (Ivanova et al. 2015) demonstrated
that ACT increased exercise enjoyment following a session of
high-intensity cycle ergometer exercise. Specifically, Ivanova
et al. (2015) provided empirical evidence for the efficacy of
ACT in reducing perceived effort, increasing exercise enjoyment,
and improving exercise tolerance for low-active women
randomized to the ACT group, as compared to the implementation
intentions group. The finding that ACT increased exercise
enjoyment and reduced perceived effort is especially relevant
to exercise behavior because exercising can be highly
exerting and/or unpleasant (e.g., Annesi 2004; Pedersen 2012;
Welch et al. 2007). In fact, 60 % of women report that they feel
nervous when exercising because of the way their body reacts
to exercising, for instance sweating or turning red (Pedersen
2012). Annesi (2004) provides further evidence for the association
between retrospective reports of tolerance for physical
discomfort during exercise and exercise behavior, wherein
tolerance of exercise-related discomfort (e.g., BI can persist
when a task is tiring, uncomfortable, and/or painful^) is
strongly and positively associated (r=.60) with self-report of
exercise maintenance. Moreover, exercise enjoyment is 1)
positively correlated with physical activity intentions (Loehr
and Baldwin 2014) and behavior (Hagberg et al. 2009), and 2)
mediates the effectiveness of physical activity interventions
and exercise adherence (Marcus and Forsyth 2009; Williams
et al. 2006). However, the practical implications of acute improvements
in exercise enjoyment and ratings of perceived
exertion needs to be established by examining exercise behavior
long-term (6 months).
Implementation intentions and ACT may provide complementary
intervention efforts, whereby the former is important
for planning and the latter for providing additional resources
(e.g., increased enjoyment; Ivanova et al. (2015)) to cope with
barriers associated with the exercise-experience itself (e.g.,
boredom, perceptions of effort). Despite the important role
of implementation intentions and ACT in predicting physical
activity behavior, research to date has not compared their effectiveness
in promoting long-term physical activity adherence.
This gap in the literature highlights the need to bring
both concepts together in a single study and to examine their
differential impact on exercise adherence. The present study,
therefore, represents a logical extension of our previous work
by providing preliminary data on comparing exercise adherence,
from baseline to 6-month follow-up, among novice exercisers
who completed a one-time implementation intentions
with those who completed an ACT intervention. Ivanova et al.
Curr Psychol
(2015) present the baseline data for 1) physical activity frequency,
and 2) exercise enjoyment between the two training
conditions outlined in the present study, specifically ACT and
implementation intentions.