How Exactly Do I “Let Go”? The Potential of Using ACT to Overcome the Relaxation Paradox

Relaxation induced anxiety (RIA) or relaxation induced panic (RIP) occurs when a person’s attempts to reduce anxiety result in increased arousal. Such paradoxical increases often occur when relaxation is viewed as the avoidance of anxiety-related experiences. In fact, passivity toward these experiences is necessary for successful relaxation. However, passivity is not always easy to understand. Acceptance and commitment therapy (ACT) has attracted increasing interest in recent years and adopts a similar position with regard to experiential avoidance. Reviewing literature on the relaxation paradox, this article argues that incorporating elements of ACT into relaxation training might help overcome some problems with passivity in relaxation.

Structured relaxation techniques have been a standard component in therapy since they were first popularized by Jacobson's progressive muscle relaxation (PMR) almost a century ago (Jacobson, 1925(Jacobson, , 1931(Jacobson, , 1938. Since then, a plethora of methods have evolved, and are subsumed under the label of relaxation (Poppen, 1998). Although the primary behavior that the practitioner engages in can often vary significantly from one technique to another, and bear little resemblance to Jacobson's original technique, relaxation training (RT) is used to treat a wide range of symptoms and disorders (Smith, 1996). It is even recommended as a general adjunct to therapy to improve clients' affect and general receptivity to treatment (Lichstein, 1988).
Superficial differences across techniques may be explained by the assertion that the state of relaxation (and its antithesis, anxiety) depends on the interaction between psychological and physiological processes, such that different techniques focus primarily on one over the other. For example, a practitioner may engage in a physical action (e.g., by slowing breathing) which will, in turn, affect the autonomic nervous system (ANS), and subsequently the individual's cognitive processes, leading to a relaxed state. Conversely, the individual may focus attention on disrupting thought patterns that cause worry or anxiety, which then leads to a reduction in physiological arousal.

When and Why Relaxation Doesn't Work
A number of authors have noted that not all clients benefit from relaxation and these negative outcomes suggest that the processes of relaxation, and particularly their relationship with anxiety, are not fully understood. For example, cases of relaxation induced anxiety (RIA; Heide & Borkovec, 1984) and relaxation induced panic (RIP; Adler, Craske, & Barlow, 1987) have been reported in the literature. In response, Lazarus and Mayne (1990) argued that RIA can be avoided by closely matching the relaxation technique to the type of anxiety experienced or even to the personality of the client. Alternatively, Heide and Borkovec (1984) argued that the nature and extent of an individual's evaluations of the relaxation technique influences the outcome, because the individual is attending to intrusive private events. Indeed, there is some evidence that individuals perceive relaxation exercises as an effort to modify or remove negative or anxiety-related private events, in a type of experiential avoidance (Wegner, Broome, & Blumberg, 1997). Smith (1996) believed that unsuccessful attempts to relax may relate to a lack of understanding of the central but difficult concept of passivity. Passivity toward private events is considered to be a fundamental component of effective relaxation (Beary, Benson, & Klemchuk, 1974). Passivity is described as a level of functional detachment from the outcome of the technique, where attention toward private events takes a non-active form (Davidson & Schwartz, 1976).
There has been increased interest in acceptance and mindfulness-based approaches in recent years and there is increasing empirical support for their efficacy (Hayes, 2004). In addition, the core philosophy of these approaches have much in common with the concept of passivity in relaxation. Mindfulness involves focusing attention on the present moment making contact with these experiences without judgment or evaluation (Kabat-Zinn, 2003). Acceptance may be conceptualized in simple terms as the antithesis of experiential avoidance in that acceptance means being able to remain in contact with private events, rather than trying to reduce their occurrence (Barnes-Holmes, Cochrane, Barnes-Holmes, Stewart, & McHugh, 2004). Acceptance and commitment therapy (ACT; Hayes, Strosahl, & Wilson, 1999), which has its theoretical basis in the relational frame theory (RFT; Hayes, Barnes-Holmes, & Roche, 2001) account of language and cognition, incorporates ideas such as acceptance, mindfulness, and cognitive defusion, and utilizes behavioral change strategies to allow clients to identify and move toward their own personal values.
This article focuses on role of passivity in relaxation. Specifically, we argue that current definitions of passivity are ambiguous and purely descriptive-describing a state of "awareness without attention" without discussing how to achieve such a state. ACT incorporates a number of techniques designed to address the language processes that mediate experiential avoidance, which could help address this problem. Furthermore, the term passivity is often used to refer to distinctly different parts of the relaxation process: the goal of the relaxation exercise, attention during relaxation, and the evaluation of private events during relaxation. We outline functional similarities between these elements of relaxation and certain core concepts in ACT. Finally, we suggest that if negative outcomes associated with relaxation are due to unintentional experiential avoidance, then re-framing relaxation in ACT terms and utilizing linguistic techniques common to ACT might increase the success of relaxation techniques in a clinical setting.

Current Usage
RT has been used for the treatment of hundreds of disorders, including general stress symptoms (Rausch, Gramling, & Auerbach, 2006) or anxiety that is co-morbid with other disorders such as obsessive compulsive disorder (OCD; Twohig et al., 2010) or schizophrenia (Chen et al., 2009). RT is most commonly used as part of a therapeutic package, in combination with a main therapeutic approach such as cognitive behavioral therapy (Lehrer, Woolfolk, & Sime, 2007). Outcome studies generally support the efficacy of relaxation in the various domains where it has been applied. However, while PMR is the most popular technique in clinical settings, the myriad of existing RT techniques and the areas they are applied need to be taken into account when considering generalized statements relating to efficacy.
Indeed, Poppen (1998) criticized the "cookbook" fashion in which RTs are slotted into existing therapeutic regimes, a practice that he felt is born out of viewing relaxation as a straightforward outcome that can be achieved by applying whichever RT is most convenient. A number of authors have noted that more consideration should be given to the specific effects of RT on different symptoms (e.g., Lazarus & Mayne, 1990).
Another issue with integrating RT with other forms of therapy is the potential interaction between the wider therapeutic approach and the process of relaxation itself. As we outline the relaxation process, the importance of how the RT practitioners interpret and interact with their own thoughts and other private events will become apparent. So too will the role of the wider therapeutic philosophy in either facilitating an approach to private events that is either conducive or detrimental to the relaxation process.

Relaxation
The term relaxation can be ambiguous, in that it is often used interchangeably to refer to three distinct ideas: the state of being relaxed, the physiological and psychological process of becoming relaxed, and the technique or exercise used to promote or achieve relaxation. To avoid confusion, we will differentiate by referring to the state of being relaxed, the relaxation process, and relaxation techniques respectively, with the term relaxation referring to the overall concept.
Being relaxed could be described as a state of equilibrium that is free from both physical and psychological tension, which ultimately culminates in the subjective experience of "being relaxed." The relaxed state is subjective in that it differs from one person to another: In the same way that stress relates to perceived demands and the individual's perceived inability to meet those demands, relaxation is not necessarily an absence of all potential stressors, rather a sense that they are not overwhelming. This sense of well-being is also dependent on the absence of sympathetic physiological activity, signaled by low heart rate, slowed breathing, and reduced muscle tension.

Somatic Responding
The objective indicators of relaxation are muscular tension and activity of the ANS. When a person is relaxed, they generally have low levels of tension in the skeletal muscular system and reduced sympathetic activity in the ANS, characterized by lower oxygen consumption, slower heart, and lower blood pressure (Benson, 1975).
The list of techniques that come under the label of relaxation is not exhaustive. However, exercises that are common to most relaxation techniques attempt to directly engage one or both of the muscular or autonomic systems. PMR involves extensive training to discriminate between different levels of muscular tension and has seen a number of iterations and abbreviated versions since its inception (Bernstein, Carlson, & Schmidt, 2007). The autonomic component of relaxation is accessed through various techniques, which aim to reduce sympathetic arousal and promote a state of "parasympathetic inhibition" (Beary et al., 1974). Breathing exercises, for example, aim to regulate and lower rate of breathing resulting in slower heart rate and lower blood pressure (McCaul, Solomon, & Holmes, 1979). Biofeedback allows the practitioners to regulate their own autonomic activity by giving a continuous visual or aural feedback indicating increases or decreases in arousal (Tarler-Benlolo, 1978). Even in techniques that might emphasize one type of responding, there is an awareness of the holistic nature of the process. For example, while never directly addressed in the exercise, Jacobson noted that PMR resulted in physiological arousal (Lichstein, 1988). While Benson (1975) emphasized mantra and breathing exercises, he noted the role of muscular tension by emphasizing the importance of comfortable posture.

Cognition
What makes the relaxation process the focus of continued fascination and study is that somatic responses are only part of the equation. Relaxation also involves a cognitive component, where previous experience, expectations, and current physical and emotional state all enter awareness and are evaluated while engaging in a technique. By its nature, relaxation involves increased self-focus, where attention is directed toward (or away from) thoughts and other private events that occur while trying to relax (Bond et al., 2009). In addition, there is a level of meta-responding, where the presence or absence of these events is evaluated to measure the overall success of the exercise (Hayes, Hirsch, & Mathews, 2010;Heide & Borkovec, 1984). While techniques such as mantra (repetition of a single word or phrase) attempt to limit the amount of self-talk during relaxation by focusing attention on a single word or phrase, all of the major models of relaxation acknowledge the fact that errand thoughts will occur.
The predominant view is that a position of passivity should be adopted toward such intrusions (Lichstein, 1988). In general, passivity is described as a neutral, disinterested position toward thoughts that enter awareness. However, the concept has been used in a number of ways, to describe a practitioner's intention (how they define being relaxed), attention (how they attend to private events during the relaxation process), and evaluation (how they interpret these events). In each case, the term passivity has slightly different connotations.
Intention. Passivity has been used to describe the view a practitioner should adopt toward the overall goal of the relaxation technique. Benson (Beary et al., 1974;Benson, 1975) suggested that practitioners should begin relaxation techniques with a "passive attitude" and not focus directly on the outcome of the technique. He described passivity as not worrying about how well the technique is being performed. Jacobson (1951) warned against overemphasizing the outcome of PMR in case it led practitioners to check how well they were following it, believing that this would disrupt progress. Davidson and Schwartz (1976) describe a detached attitude toward the functional outcome of the technique being engaged in.
Evaluation. Passivity is also advocated in terms of how an individual interprets private events. Thoughts or sensations that occur during relaxation can be viewed as aversive (to be avoided or removed) or benign (to be tolerated). This evaluation can have a direct affect on physiological activity. For example, Ray et al. (2009) found that the strength of physiological responses to a novel stimulus were determined more by whether or not the participant evaluated the stimulus as negative beforehand, than their arousal level prior to stimulus presentation. It is, therefore, important that unintended private events are considered to be part of the relaxation experience, as opposed to unwanted intrusions.
Attention. Attention relates to the manner in which a practitioner observes psychological and physiological events that occur while engaging in a relaxation exercise. It is commonly described along two dimensions: direction (self-or externally-focused) and activity (active or passive; Bond et al., 2009;Davidson & Schwartz, 1976).
The direction of attention in relaxation is considered to be self-focused, in that focus is directed toward physiological or psychological activity. Practitioners are instructed to attend to their rate of breathing as they slow their breath, their level of muscle tension as they learn to relax certain muscles, or their thoughts as they engage in meditation.
However, not all events should be attended to in the same way. Davidson and Schwartz (1976) distinguish between passive and active attention, where active is effortful and passive is not. Active attention should be directed toward the current activity (e.g., breathing exercises), while all other private events (e.g., thoughts or physical sensations) should only be passively attended to. Similarly, Benson (1975) instructed practitioners to disregard any thoughts that occur while engaging in the relaxation exercise and redirect attention toward the technique.

Paradoxical Effects
As well-documented as the process of relaxation has become, the fact remains that attempts to relax are not always effective. Indeed, there continue to be documented cases of RIP and RIA, where attempts to relax actually lead to a state of increased arousal or anxiety. Individuals who experience this phenomenon are unable to become proficient at relaxation and can become upset by their heightened awareness of the changing internal states associated with relaxation (Lazarus & Mayne, 1990). Lazarus and Mayne (1990) suggested that RIA and RIP type outcomes could be avoided if the chosen technique was appropriate to the symptoms being alleviated. However, other explanations for the cause of the paradoxical effects phenomenon and the wide variety of techniques that have elicited these effects suggest commonalities across sufferers and the importance of the passivity concept. Heide and Borkovec (1984) outlined what they considered to be some of the features of RIA: (a) aversion to (ostensibly positive) private events that occur as a result of relaxation, (b) attempting to achieve relaxation through effort to control experiences, (c) focusing attention on anxious thoughts that enter awareness, (d) unwillingness to generally attend to internal events, and (e) worrisome cognitive activity unrelated to relaxation.
The points outlined by Heide and Borkovec (1984) suggest that RIA is likely to occur when an individual attempts to avoid or control private events that occur during relaxation. Of particular note is the first point, which emphasizes the subjective nature of this phenomenon. That is, physiological or psychological changes that occur during relaxation, some of which are actually associated with achieving a relaxed state, are all evaluated by the individual as aversive. As such, they attempt to achieve relaxation by gaining control over such experiences. Wegner et al. (1997) explained how these attempts to gain control could lead to increased arousal. He suggests that once control is sought, the individual begins to monitor for any intrusive thoughts, to suppress or remove them. It is suggested that this disrupts the relaxation process in two ways. First, instead of passively attending to private events, the practitioner is now actively and continuously monitoring for their presence, so that they can be suppressed. This itself can increase arousal (Jacobson, 1931). Second, attempts to suppress have been shown to disrupt physiological habituation to events. In a sense, each new anxious thought is treated as a novel stimulus, whose presence was never allowed and therefore never habituated to, so that the strength of the somatic response does not diminish over time (Ray et al., 2009;Wegner, 1994). The role of passivity then is to adopt a position toward private events that allows them to occur, facilitating habituation and leading diminished physiological and emotional responses to new events over time.

Problems With Passivity
RIA and RIP might be considered as extreme examples of what can take place during relaxation. It could be argued that where they occur, the process of relaxation has been misinterpreted: as an exercise in effortful control, rather than passive habituation. However, there is evidence to suggest that relaxation is indeed interpreted in this manner. For example, Wegner et al. (1997) demonstrated that the instruction "to relax" resulted in larger increases in physiological arousal, when engaged in a stress-inducing task, compared with those who were not so instructed. They argue that relaxation is open to interpretation as an exercise in suppression or avoidance, and in fact, it is commonly viewed this way. The authors suggest that increased cognitive load at the time might constitute the difference between there being no paradoxical effects and the type of increased arousal associated with RIA and RIP.
It is important therefore that passivity is communicated as an integral part of relaxation. Given that relaxation is a very verbal process, involving constant reflection on physical and psychological events, the language used to articulate an idea such as passivity becomes especially relevant. Depending on how passivity is described, it is possible that the instruction to "be passive" could be misinterpreted in the same way that the instruction "to relax" often is. Here, we outline the potential difficulties that could arise when attempting to communicate the role of passivity in relaxation. We suggest that if the goal of relaxation is to facilitate habituation to private events, then there are a number of key points that need to be understood.

Intention: Identifying the Goal
To the practitioner, the main goal of relaxation is to "not feel anxious." As such, directly addressing this anxiety seems like the obvious first step in achieving this aim. When advocating passivity, we are asking the practitioner not to do this. Instead, we are suggesting that they attend to all private events that occur and experience them fully without attempting to avoid, modify, or control them. Previously for the practitioner, relaxation was the absence of these feelings. Now, a new indicator is needed to rationalize an experiential as opposed to avoidant approach. In other words, "Why should I allow myself to experience all of the thoughts and sensations that I associate with anxiety-the very state I do not want to be in?" Smith (1996) acknowledged the difficulty of advocating passivity for its own sake. He suggested that the practitioner should learn to adopt "a personal philosophy of passivity" in their daily lives, where the locus of control is outside of the relaxation exercise. The goal for relaxation cannot be the removal of thoughts, emotions, or physical sensations, as this is the same control-oriented approach that lead to the aforementioned paradoxical effects. Instead, a larger external goal must be identified, such as the actions in life that the anxiety was heretofore preventing. With this external task set as the "real" goal of relaxation, fluctuations in somatic arousal or the presence of unwanted thoughts that occur during relaxation no longer need to constitute a failure to relax, so long as there is movement toward the external goal.

Evaluation: Severing the Link Between Internal Events and Anxiety
A fearful reaction toward bodily sensations or other private events that have been previously associated with panic or anxiety is a well-known mediator of the anxiety process (Smits, Powers, Cho, & Telch, 2004). In an attempt to determine the mechanism of change in cognitive behavioral therapy (CBT) treatments of panic disorder, Smits et al. (2004) found that a reduction in fear of fear (FOF) accounted for the largest variance in symptom reduction.
It is difficult for practitioners to adopt a passive view of such private events, when they are so inextricably tied to the aversive experience. Simply advocating passivity does nothing to sever this link. It is important to take steps to actively disrupt this link, so that private events may be viewed as benign and not as signals of an impending unwanted experience.

Attention: Clarifying What Is Active and What Is Passive
It is difficult to describe passivity in a manner that articulates the correct balance between activity and inactivity. On the one hand, it is possible that passivity could be interpreted simply as a lack of activity, in that the aim is to observe and not react to thoughts. However, it would be incorrect to say that passivity is the same as doing nothing, as clearly it is a specific type of response to observed private events. Ironically, it is also possible that passivity could be interpreted as an activity. Phrases such as "clearing the mind," "letting go," or "observing" are all used to communicate this process in relaxation exercises. It is worth noting that linguistically, all of these terms imply two things: (a) some type of activity is necessary and (b) that activity involves directly addressing private events.
In fact, what we are trying to communicate with these phrases is an ongoing willingness to experience unpleasant private events, described by Smith (1999) as receptivity. If, as we said previously, private events must be allowed to occur to habituate them, then there must be a willingness to allow them to occur. Maintaining this willingness is the active element in relaxation.

Acceptance
There are a number of functional similarities between the passivity component of relaxation and psychological acceptance. Acceptance emphasizes being able to remain in contact with private events, rather than trying to reduce their occurrence (Barnes-Holmes et al., 2004). ACT (Hayes et al., 1999) incorporates acceptance and mindfulness as well as focusing on valued action. From an ACT perspective, the paradoxical effects of effortful relaxation are not unexpected, given the ACT position that attempts to alter the form of frequency of internal events can lead to psychological problems (Kashdan, Barrios, Forsyth, & Steger, 2006).
ACT also comprises a number of techniques, which are designed to show the futility of experiential avoidance and facilitate acceptance. In this section, we will outline the components of ACT that are comparable to the various stages of relaxation outlined previously.

Intention: Valued Action as the Goal
Personal values can be described as desirable, transsituational concepts or beliefs concerning life goals (Biber, Hupfeld, & Meier, 2008). Essentially, what people consider important. Valued actions are those steps taken by an individual towards their personal values. The concept of values is not strictly limited to ACT; however, the ACT approach has been commended for the fact that it addresses values so explicitly and directly (Arch & Craske, 2008). Barrow and Prosen (1981) identified the importance of values clarification in relaxation as part of their model for stress and counseling interventions, a multi-point model of the stress process. Within this model, the authors outline the interaction between internal and external demands that takes place when first situational variables and then internal events are perceived to be "out of control" of the individual. As part of their approach, they suggest that values clarification is necessary so that the emphasis in relaxation is not placed entirely on the internal struggle, which can often descend into maladaptive self-talk and focus on regulation of internal psychological and physical states.
Recent literature in the area of pain tolerance has exemplified the potential benefits of identifying values in facilitating acceptance of aversive physical states. McCracken and Yang (2006) found that success in valued action facilitated acceptance as opposed to avoidance of pain, in chronic pain sufferers. Similarly, Garcia, Villa, Cepeda, Cueto, and Montes (2004) found that an acceptance-based intervention that centered on values allowed athletes to accept the presence of certain bodily states and private events during an exercise and focus on increasing their performance.
Branstetter-Rost, Cushing, and Douleh (2009) found that the inclusion of the values component in an acceptancebased intervention led to significantly greater tolerance of pain in a cold-pressor task compared with an intervention without the values component. This indicates that the identification of personal values prior to engaging in a relaxation exercise may create a context where changes in physical or psychological states are more acceptable, due to the presence of a greater external goal.

Evaluation: Defusion
Fusion is the idea that thoughts must be countered or acted upon if they are acknowledged because they in some way reflect external reality or are a precursor to an inevitable chain of events, such as becoming anxious. This perspective has been discussed in relation to anxiety with the FOF hypothesis, wherein the thoughts and bodily sensations associated with the anxious state during a previous distressing experience become as feared as the original events that precipitated the anxiety. Any appearance of similar thoughts or sensations is then interpreted as a signal that the anxious state is about to reoccur.
Within this sequence, we can see the strong association between what could be an isolated and quite common private event (an errand thought or an awareness of physiological change) and an eventual state of anxiety, leading to the evaluation that any such event is unwanted and should be tackled. Here, the private event functions as an aversive stimulus that elicits further verbal and physiological responses.
In ACT, this view, that thoughts are literal reflections of reality, is known as fusion. ACT takes a different perspective: that thoughts are not literal and so do not need to be responded to. Strategies such paradox, mindfulness, and cognitive distancing aim to break the symbolic relationship between thought and external reality by disrupting how the thoughts function, rather than trying to directly modify their content or frequency (for a full theoretical outline of defusion, see Blackledge, 2007).
Recent studies have begun to demonstrate the positive effects of defusion (e.g., Healy et al., 2008). In addition, recent findings by Hayes et al. (2010) exemplified exactly how defusion might be beneficial in the relaxation process. The authors found that facilitating a benign attentional bias reduces the frequency of negative thought intrusions. This indicates that once the tendency to evaluate private events as negative is altered, the events themselves will occur less frequently. This finding is particularly interesting as it demonstrates a way around the relaxation paradox: While attempting to directly reduce the frequency of events may cause paradoxical increases, their occurrence can be reduced indirectly by facilitating a benign approach. Defusion is one potential way this can be achieved.

Attention: Acceptance and Willingness
The identification of personal values and the concept of defusion could be considered to take place outside of the relaxation "exercise," be it PMR, focused berating, or a meditative technique. Once personal values have been identified and the process of defusion begun, there is a need to identify what a practitioner should do during the exercise when aversive private events occur.
Previously is has been suggested that the individual should "passively attend" to any such events, while actively attending to the relaxation technique (Davidson & Schwartz, 1976). However, it could be argued that the active/passive dichotomy is misleading, particularly in relation to passive attention, in that it suggests that no reaction to private events should take place. Given the aversive nature of these thoughts and bodily states, it would seem that the very act of allowing them to take place requires some effort on the part of the individual. Such an effort would have a markedly different function than trying to avoid or suppress events, but it would be an effort nonetheless. Smith (1999) recognizes this in his ABC relaxation model, wherein he identifies a need for "receptivity" to these events. Receptivity implies the opposite of avoidance, while also implying an ongoing conscious decision to allow events to occur.
In ACT, there are separate but inextricably linked concepts of "acceptance" and "willingness." In terms of process, willingness to experience unwanted thoughts and states is necessary to accept them. Willingness therefore, is the active attentional element when it comes to dealing with aversive private events as they occur: Prior to the events entering awareness, the individual makes the conscious decision of being willing to experience them. Acceptance is the passive element in that events are experienced without attempts to modify or control them. A recent study by Wilson, Barnes-Holmes, and Barnes-Holmes (2014) found that an ACT-based intervention demonstrated different patterns of physiological responding in an anxiety-inducing situation than other strategies including mindfulness and placebo, suggesting that effective mitigation of anxiety responses is more than "doing nothing." Willingness is directly addressed in ACT and linked to the personal values of the individual. Once personal values have been identified, willingness to experience short-term discomfort is discussed in terms of movement toward longterm personal values. Increased willingness to experience aversive states has already been found to be associated with decreased experiential avoidance and positive changes in anxiety (Twohig, Hayes, & Masuda, 2006).

ACT and Relaxation Comparisons
Although we mentioned previously that it is common practice to integrate RTs into larger therapeutic techniques, experimental studies often examine them in isolation, comparing their efficacy directly with other therapeutic approaches such as CBT. The rationale for such comparisons is, of course, to broaden the range of effective treatment options for any particular disorder, by comparing a new technique with one were the efficacy has already been established. Twohig et al. (2010), for example, found that ACT produced favorable outcomes on a number of post-treatment measures of OCD, when compared with progressive RT.
However, it could be argued that where relaxation has been proven to be effective, some of the mechanisms for change that facilitate positive outcomes with the new approach are largely present in the RT as well (Smits et al., 2004). In addition, RT in some form is often added to therapeutic approaches wherever anxiety or stress-reduction is necessary because of its role in reducing somatic arousal (Poppen, 1998). Rather than view relaxation techniques as a separate entity, it would seem more productive to identify those elements within RTs that facilitate change and highlight them in the therapy being combined with. This would potentially lead to more effective and holistic results.

Conclusion
This article argues that acceptance and passivity are functionally similar concepts. However, acceptance from this perspective appears to offer a number of distinct advantages: (a) It is intuitively easier to work out what you are required to do when you are accepting, especially when willingness is incorporated, rather than when you are being passive. Put simply, it is easier to learn how to "be willing to have the feelings that are showing up" than to learn to "let go," "calm down," or "do nothing." (b) The link between acceptance and personal values also gives your therapeutic efforts meaning, especially in a context where you are being asked to accept psychological content that is unpleasant or aversive. So, for relaxation you not only know how to accept your content, but you also know that you are doing this in an effort to move toward what you value. Hence, acceptance and values, however they are conceptualized, are a necessary part of effective relaxation.
Traditional descriptions of relaxation emphasized the importance of passivity toward thoughts and sensations, yet there was little in the way of explanation of "how to be passive" because passivity is easily but incorrectly interpreted as the absence of activity. In contrast, there is reason to conceptualize passivity as a more than this by acknowledging the necessary willingness to experience events. This is supported by studies such as Wilson et al. (2014), where different patterns of physiological responding were seen from participants who did nothing, compared with an intervention that incorporated a willingness element.
Finally, we suggest that integration of the principles of relaxation into larger therapeutic approaches offers a more complete understanding of how relaxation works or does not work, as relaxation techniques are invariably influenced by the philosophy of the therapy they are a part of.

Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding
The author(s) disclosed receipt of the following financial support for the research and/or authorship of this article: This research was supported by The Irish Research Council for Humanities and Social Sciences scholarship for doctoral research awarded to Christopher Wilson.