5.2: Predicting Physical Activity

Theories are useful to select factors that can explain physical activitybehavior.Below are several of the major theories used by researchers to study physical activity and sedentary behavior. These theories were chosen due to their predictive utility, practical implications, and empirical support and are not an exhaustive list of the theories used in sport and exercise psychology. The following theories fit within three general categories (see Rhodes et al.,2019 for a more detailed review). The social-cognitive category contains theories that view behavior as a function the beliefs and thoughts of people. This category views decisions to enact behavior as deliberate and intentional. The humanistic or organismic category views behavior as a function of the innate needs of people to grow, develop, and effectively interact with their environment. The third category adds that behavior is a function of both reflective (similar to those of social-cognitive theory) and automatic processes. Automatic processes are rapid and more difficult to be aware of than slower, reflective, more conscious processes. The following theories are presented below in a succinct fashion to offer readers an overview of the main factors of the theory, research support, implications for practice,and challenges.

5.2.1. Theory of Planned Behavior

Intention is the most proximal predictor of physical activity according to the Theory of Planned Behavior (Azjen, 1991). Intentions represent when people plan to act and perform a behavior. Intentions are most likely to cause behavior when those intentions are strong and only when they are out of volition of the performer. Intentions are influenced by three predictors: attitudes—a valenced (favorable or unfavorable) evaluation about the behavior, subjective norms—perceived social influence from others to perform or not perform the behavior,and perceived behavioral control—the perception of performing the behavior as easy or difficult (Ajzen & Fishbein, 1980). In addition to predicting intentions, perceived behavioral control can also directly predict behavior when perceptions of control are realistic. When individuals view physical activity as important and believe they are in control of their behavior they will intend to be physically active (Rhodes et al.,2019).

Meta-analytic evidence supports intentions and perceived behavioral control as positive predictors of physical activity (Hagger et al.,2002; McEachan et al., 2011). Attitudes and perceived behavioral control appear as consistent predictors of intentions. The typical effects of attitudes, social norms, and perceived behavioral control on intention to be physically active are of medium magnitude (McEachan et al., 2011). Subjective norms appear as a less consistent predictor of intentions compared to attitudes and perceived behavioral control. The inconsistency of subjective norms may due be to conceptualization and measurement issues (Kim et al., 2019). Subjective norms are more likely to predict intentions when they are measured as observing other important people’s behaviors. The inclusion of subjective norms to predict intention to be physically activeis complex (Kim et al., 2019).Furthermore, mixed support for the role of subjective norms exists among populations with physical disabilities (Kirk & Haegele, 2019).

In practice, numerous interventions used the theory of planned behavior to affect changes in intentions as well as physical activity behavior (Webb & Sheeran, 2006). Interventions focus on changing the attitudes, subjective norms, or perceptions of control of people to produce stronger intentions to be physically active. Research findings show that even though interventions that can change the intentions of people, this does not always lead to changes in behavior (Chatzisarantis & Hagger, 2005; Webb & Sheeran, 2006). This has led to criticisms of how useful the theory of planned behavior is for changing the physical activity of people (Sniehotta et al.,2014). Although the components of the theory of planned behavior are empirically supported, the application of this theory to improving physical activity behavior is less clear.

5.2.2. Social-Cognitive Theory

A key factor of social-cognitive theory (Bandura, 1997, 2005) that predicts behavior is self-efficacy—the degree of confidence to exert control over one’s behavior (Bandura, 1997).Self-efficacy is often referred to as a situation-specific form of self-confidence.This theory supports the idea that the more confident people are in their abilities,the more likely they will be physically active. The broader components of social-cognitive theory include knowledge, outcome expectations, perceived facilitators and impediments (see Bandura, 2005). Individuals develop their physical activity efficacy beliefs from four primary sources, namely past performance accomplishments (e.g., a runner achieving their personal best in a race), social persuasion (e.g., encouragement from a friend to run), vicarious experiences (e.g., observing other’s compete in races), and interpretation of physiological and affective states (e.g., awareness of positive feelings when running; Bandura, 1997). Self-efficacy can influence what behaviors people chose to pursue (i.e., choice), how much effort people put forth in pursuit of their goals (i.e., effort), and the how long people persist despite setbacks or challenges (i.e., persistence). Note that this chapter describes four sources of self-efficacy, but others have conceptualized six sources of self-efficacy (see Chapter 27; Hepler et al., 2021).

People will be more likely to be physically active if they perceive they can be successful at it(Samson & Solmon, 2011). Self-efficacy has shown to be one of the strongest psychological predictors of physical activity (Hu et al., 2007). Successful behavior is likely to increase self-efficacy and increased self-efficacy leads to an increased likelihood of effort and persistence. This represents a cyclical association between self-efficacy and behavior over time (McAuley & Blissmer, 2000). This cycle may be most helpful for people who are physically inactive. An initial successful physical activity experience can have strong effects on self-efficacy and be the impetus for this cyclical association.

Research shows that past performance accomplishments are one of the strongest positive predictors of self-efficacy (Warner et al.,2014). Interventions based on social-cognitive theory should emphasize these mastery experiences to develop self-efficacy. Additionally, interventions can focus on social persuasion through feedback and reinforcement,and vicarious experiences such as modeling proper form and technique,to positively influence self-efficacy beliefs towards physical activity. Social influence appears to be a significant predictor of physical activity behavior across the adult lifespan (De Bourdeaudhuij & Sallis, 2002).

5.2.2.1. Considerations for Social-Cognitive Theories

The definition and measurement of intentions vary across studies despite being an important predictor of behavior (Rhodes & Rebar, 2017). There exist two distinct concepts of intention: decisional intention—decisional direction to enact the behavior or not and intention strength—intensity of commitment to enact behavior. Rhodes and Rebar (2017) conclude that intention strength appears to be a better predictor of behavior whereas decisional intentions allow for closer examination of factors leading up to decisions and factors that follow decisions. Future research should make these concepts clearer to readers due to their different empirical and practical implications (see Rhodes & Rebar, 2017).

Despite the relevance of importance of factors in the theory of planned behavior, it has shown limited predictive validity (Sniehotta et al., 2014). When accounting for how much physical activity can be predicted by social-cognitive factors, there generally remains a large proportion of the variance unexplained. This means there are additional factors outside of those used in social-cognitive theories that could enhance the explanation of physical activity behavior.

This chapter introduces the sources of self-efficacy,but readers should be aware that there are more sources of self-efficacy that may contribute to a person’s situation specific self-confidence.For example, the tripartite view of self-efficacy beliefs demonstrates that social relationships can meaningfully impact a person’s self-efficacy through relation-inferred self-efficacy and other efficacy beliefs (Lent & Lopez, 2002). For instance, a track athlete perceiving her coach to hold favorable views of her sport ability would positively impact the athlete’s self-efficacy. Practitioners could leverage relation-inferred self-efficacy by incorporating strategies to enhance the quality of social relationships within physical activity settings.

5.2.3. Self-Determination Theory

The basis of self-determination theory is that people are growth-oriented organisms that behave in ways to grow and develop their skills (Deci & Ryan, 2000; Ryanet al., 2009). Self-determination theory is also discussed in Chapter 2(Rebar et al., 2021), Chapter 3 (Quested et al., 2021) and Chapter 32 (Kingston et al., 2021). This theory integrates many sub-theories that culminate into identifying the major personal and contextual factors that influence human behavior. The theory has been widely used to study physical activity motivation (Hagger & Chatzisarantis, 2008; Teixeira et al., 2012) and inform interventions to increase physical activity behavior (Ntoumanis et al., 2020). Self-determination theory focuses on three broad types of motivation that occur along a continuum of self-determined behavior. Self-determined motivation is the most optimal and highest quality motivation. This type of motivation includes intrinsic and extrinsic reasons tied to enjoyment, interest, and personal values. Controlled motivation represents the second type of motivation that includes reasons tied to external pressure and rewards. The third type is a motivation that represents the absence of intentions and sense of control to behave. Research generally shows that self-determined motivation is the most adaptive type of motivation for the promotion of physical activity (Hagger & Chatzisarantis, 2008; Teixeira et al., 2012)

For an individual to be optimally motivated, they must perceive fulfillment of three basic needs in a given context (Ryan & Deci, 2000). The need for autonomy represents individual authenticity in their behavioral decisions (i.e., sense of personal choice). The need for competence represents effective functioning (i.e., sense of ability to bring desired behavioral outcomes). The need for relatedness represents the social connectedness to others (i.e., sense that others accept, care for, and value an individual). The degree to which these needs are perceived to be fulfilled impacts self-determined motivation of individuals.

Research findings generally support the tenets of self-determination theory. More self-determined types of motivation are positive predictors of physical activity (Duncan et al., 2010; Standage et al., 2008). Research shows autonomy, relatedness, and competence needs are positive predictors of more self-determined types of motivation in physical activity contexts (Teixeira et al., 2012). Experimental evidence shows supporting the needs of autonomy, competence, and relatedness through need supportive text messaging may lead to greater need fulfillment and increases in moderate intensity physical activity (Kinnafick et al., 2016). Other research has taken a more person-centered approach to self-determination theory because people may hold multiple reasons simultaneously for engaging in physical activity. For example, children who reported primarily a combination of self-determined motives from young childhood to late childhood showed the highest levels of physical activity compared to those holding more controlling motives or a motivation towards physical activity (Emm-Collison et al., 2020).

Self-determination theory has led to many practical implications for interventions based on a substantive body of supporting empirical evidence. Although these interventions may lead to small positive changes in health behaviors including physical activity (Ntoumanis et al., 2020), those wishing to increase physical activity may be best served to implement strategies that fulfill the needs for autonomy, competence and relatedness.This may be most influential by training leaders of physical activity environments such as coaches, trainers, and physical educators for how to support the psychological needs of their participants.

5.2.3.1. Considerations for Self-Determination Theory

There exist a few challenges with self-determination theory despite its widespread adoption in sport and exercise psychology. One challenge is whether the three basic needs of autonomy, competence, and relatedness are a complete conceptualization of the needs necessary to influence motivation. Preliminary evidence has identified the need for novelty as an additional basic psychological need (González-Cutre et al., 2020). The need for novelty is the need to experience something new or differs from experiences of everyday life. The need for novelty may be useful to sustain motivation in physical activity environments to avoid staleness or boredom with repetitive tasks. Understanding the relative contributions of the need for novelty is warranted in future research.

Another consideration for self-determination theory is whether individual characteristics make people sensitive to need fulfillment. For instance, people who are deprived of supportive and positive social relationships in daily life may be more sensitive to the effects of the need for relatedness in physical activity contexts. A related point first formalized by Vallerand (2001) is that basic needs and motivations are classified at three levels of generality: the global, contextual, and situational. According to this perspective, a contextualized need for relatedness should be most strongly related to motivation for a particular behavior within that context (i.e., specificity hypothesis, Vallerand, 2001). For example, an individual who has weak social connections within her family may be more sensitive to the effects of the need for relatedness when she participates in a group-based exercise class. Studying this multilevel influence within and across social complexity may inform researchers and practitioners which individuals may be most receptive to behaviors that fulfill basic needs. Future research would benefit from analyzing the factors of self-determination theory across these levels to obtain a better understanding of individual differences.

5.2.4. Dual-Process Models of Behavior

Dual-process models provide a framework for how two systems influence behavior (Strack & Deutsch, 2004). Dual-process theories are also discussed in Chapter 4 by Brand & Ekkekakis (2021), and Chapter 2 by Rebar et al. (2021).The first system is reflective that uses explicit processes through deliberate thought and conscious awareness to influence behavior. Social-cognitive theories fit within this system to study physical activity behavior. The second system is reflexive, concerned with sometimes nonconscious, automatic and implicit processes that influence behavior.Such reflexive processes are less studied in physical activity. They may also be best positioned to study sedentary behavior as decisions to be sedentary are less likely to require as much deliberate thought and planning (i.e., reflective processes) as physical activity.

Studying reflexive processes is advancing understanding in physical activity and sedentary behavior research (Bluemke et al., 2010, Rebar et al., 2016). Examples of such reflexive processes include habits (e.g., Rebar et al., 2014), implicit attitudes (e.g., Banting et al., 2009), automatic evaluations(e.g., Conroy & Berry, 2017), and approach-avoidance tendencies (e.g., Zenko & Ekkekakis, 2019a). Sometimes terms such as automatic associations and implicit attitudes are used interchangeably (for a discussion on choice in terminology, see Zenko & Ekkekakis, 2019b). Research shows that reflexive processes uniquely and positively contribute to the prediction of physical activity (Rebar et al., 2016). This research area is still in its infancy but the incorporation of reflexive processes in the prediction of physical activity has provided a more accurate picture of the factors that can determine behavior.

Practical implications of how to intervene on training the reflexive processes of individuals to increase physical activity behavior has received empirical support. Computer-based conditioning tasks may change automatic evaluations of exercise that could result in changes to the choice and duration of physical activity behavior (Antoniewicz & Brand, 2016; Cheval et al., 2016). These computer-based trainings may be especially important for when individuals are restricted from exercise and recreational facilities (i.e., COVID-19 pandemic). Beyond computer-based trainings, in-person interventions that are effective at changing reflexive processes and in turn physical activity behavior are needed. Such interventions outside of laboratory environments may be more easily translated into practice for the public.

5.2.4.1. Considerations for Dual-Process Models of Behavior

Issues related to inconsistent terminology among reflexive processes and how to measure these processes represent current limitations of dual-process research. Zenko & Ekkekakis (2019a) addressed the issue of measurement by assessing the reliability and validity of nine measures of implicit processes. Results showed that only three of the nine measures showed acceptable reliability and only the approach-avoidance task demonstrated validity, showing significant correlations with self-reported exercise behavior and situated decisions toward exercise(i.e., decisions about exercise when a behavioral alternative is available; Brand & Schweizer, 2015).As this line of research progresses, standardizing the terminology and refining measurement will help research progress and extend understanding of reflexive processes.

Beyond terminology, the reflexive process may be particularly useful to study sedentary behavior. Of the growing body of research studying reflexive processes in sport and exercise psychology, sedentary behavior remains understudied. The nature of sedentary behavior appears to align well with the concept of reflexive process—that sedentary behavior does not require deliberate thought or action. Dual-process models may be especially important to intervene on sedentary habits. Such research may lead to a greater understanding of how sedentary time accrues or how to break habits of extended sedentary time.