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Drivers of Change in Mindfulness- and Acceptance-Based Drivers of Change in Mindfulness- and Acceptance-Based Interventions with Athletes: Investigating the Influence of Dosage, Readiness, and Attitudes Interventions with Athletes: Investigating the Influence of Dosage, Readiness, and Attitudes Thomas O. Minkler tom0007@mix.wvu.edu Follow this and additional works at: https://researchrepository.wvu.edu/etd Part of the Exercise Science Commons, Other Kinesiology Commons, Other Psychology Commons, and the Sports Sciences Commons Recommended Citation Minkler, Thomas O., "Drivers of Change in Mindfulness- and Acceptance-Based Interventions with Athletes: Investigating the Influence of Dosage, Readiness, and Attitudes" (2023). Graduate Theses, Dissertations, and Problem Reports. 11968. https://researchrepository.wvu.edu/etd/11968 This Dissertation is protected by copyright and/or related rights. It has been brought to you by the The Research Repository @ WVU with permission from the rights-holder(s). You are free to use this Dissertation in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you must obtain permission from the rights-holder(s) directly, unless additional rights are indicated by a Creative Commons license in the record and/ or on the work itself. This Dissertation has been accepted for inclusion in WVU Graduate Theses, Dissertations, and Problem Reports collection by an authorized administrator of The Research Repository @ WVU. For more information, please contact researchrepository@mail.wvu.edu. Drivers of Change in Mindfulness- and Acceptance-Based Interventions with Athletes: Investigating the Influence of Dosage, Readiness, and Attitudes Tommy Minkler, MA A Dissertation submitted to the College of Applied Human Sciences at West Virginia University in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Sport, Exercise, and Performance Psychology Sam Zizzi, Ed.D., Chair D. Jake Follmer, Ph.D. Johannes Raabe, Ph.D., CMPC Zenzi Huysmans, Ph.D., CMPC Department of Sport, Exercise, and Performance Psychology Morgantown, West Virginia April 2023 Keywords: Mindfulness, MABI, Student-Athlete, Dosage, Readiness, Attitudes Copyright 2023 Thomas O. Minkler Abstract Drivers of Change in Mindfulness- and Acceptance-Based Interventions with Athletes: Investigating the Influence of Dosage, Readiness, and Attitudes Tommy Minkler, MA Mindfulness- and Acceptance-based interventions (MABIs) are being used with increasing frequency with sport participants. Research suggests that such interventions may promote sport performance and impact performance-relevant factors, although the current quality and quantity of research is low. Specifically, questions about intervention engagement (i.e., dosage), potentially impacted by stage of change and attitudes toward sport psychology, need clarification. The present study utilized a multi-method, quasi-experimental longitudinal design with female- and male- identified NCAA collegiate athletes to investigate the effects of an MABI. Specifically, one NCAA Division II team (n = 16) and three NCAA Division III teams (n = 43) from two universities in the Appalachian region engaged in 6-week Mindful Sport Performance Enhancement (MSPE) interventions during their offseason or pre-season training period. Two teams served as the primary treatment group while two others served as the non randomized waitlist control group; they were all assessed on measures of flow, psychological distress, mindfulness, emotion regulation difficulties, satisfaction with life, readiness to engage in mindfulness practice, attitudes toward sport psychology, and subjective ratings of performance and enjoyment. Mindfulness dosage was also measured throughout and following the intervention. Compared to controls, initial MSPE participants reported reductions in depressive symptoms and emotion regulation difficulties, and improvements in self-rated sport performance; at 6-week follow-up, initial MSPE participants reported significant increases in mindfulness and sport enjoyment, in addition to sustained reductions in emotion regulation difficulties. Though pre-intervention readiness did not predict changes across the intervention, higher post-intervention readiness classification was associated with improvements in mindfulness, life satisfaction, and sport enjoyment. Higher post-intervention readiness was also associated with significantly more engagement (i.e., dosage), though neither dosage nor attitudes toward sport psychology demonstrated evidence of moderation on the relationship between readiness and outcomes. These data suggest that readiness may impact engagement in MABIs, though it is still unclear whether there are indirect effects of dosage and attitudes toward sport psychology on outcomes in MABIs with athletes. DRIVERS OF CHANGE IN MABIS Acknowledgements iii For the support I have received from all who have been a part of my journey so far, I am exceedingly thankful. My path had been forged in large part because of my family. I would not be doing what I am without the memory of my dad—thank you for modeling decency and integrity, and for igniting a fierce curiosity in me. I owe an incalculable debt of gratitude to my mom for her strength and unselfishness in her vital role in our family. I am also especially grateful for Jamie, Annie, Patrick, Adam, Meg, Lilly, and Sophie, who have kept me grounded and continue to remind me what is truly important in life. I love you all and deeply value the unique contributions you all provide to me and the world. Liefje Megan: I am so fortunate to have been supported by you over the last five years. Your presence in my life elevates me and helps me to be a better person every day. Louie and I love you, and I am so thankful for all you do, and have done, in helping me and us grow. One day I’ll find the words, in Dutch, to describe how I feel, but for now—Ik hou van ons leven samen. To Dr. Zizzi: My doctoral studies were made exponentially more enjoyable due to the support and mentorship I received from you. Your ability to connect with and support people where they are is exceptionally rare. My development under your guidance has left an indelible mark, and I will aspire to be the kind of person and professional that you are for the remainder of my life. To Carol and my friends at Catholic: Without your mentorship, Carol, I would not be in the position I am today. Your support has catalyzed my growth and development. I cannot thank you enough for introducing me to this field and continuing to mentor me through retirement. Your devotion to your students is something I will always take with me. To Laurel, Josh, Ashley and everyone at Whole Brain Solutions: Thank you for taking a chance on me and supporting my growth process in so many ways. My professional excitement has grown considerably since having the opportunity to learn from and collaborate with you all. To Coach P, Jay, Todd, and my other mentors and friends from Ohio Wesleyan: My time in Delaware, OH launched me on a path I could have never imagined. The experiences I had and lessons I learned with and from you all have shaped me in countless ways, and I am grateful. To BR, Coach Bordley, and my mentors and friends from Landon: Thank you for nurturing and pushing me to pursue curiosity and excellence when I needed it most. The foundation I gained during my time within the white rocks was formative in every way possible. To friends, colleagues, and mentors at West Virginia: Before starting at WVU, I heard how phenomenal our program and the community was from so many people—from exceptional training and mentorship opportunities to professional connections, I knew that I would be learning from and with the best in our field. What I did not fully comprehend was the camaraderie and connection that I would be getting, which has been integral in my completion of this program. To my cohort, Blake and Luna, in particular, I feel so incredibly grateful for your friendship. You have supported me in ways that words cannot describe. “This is a fine chance to let go, to ‘win my life by losing it,’ which means not recklessness but acceptance, not passivity but nonattachment” – Peter Matthiessen DRIVERS OF CHANGE IN MABIS Table of Contents iv Introduction………………………………………………………………………………. 1 Method…………………………………………………………………………………… 9 Research Design……………………………………………………………………… Sampling and Recruitment…………………………………………………………… 9 9 Participants…………………………………………………………………………… 10 Assessments…………………………………………………………………………… 11 Intervention…………………………………………………………………………… 19 Procedure………………………………………………………………………………. 19 Consulting Orientation, Experience, Education, and Positionality……………………. 22 Data Analysis………………………………………………………………………….. 24 Results……………………………………………………………………………………... 25 Discussion…………………………………………………………………………………. 36 Limitations and Future Directions………………………………………………………… 42 Conclusion………………………………………………………………………………… 45 References…………………………………………………………………………………. 46 Tables……………………………………………………………………………………… 58 Extended Review of the Literature………………………………………………………... 71 Extended References……………………………………………………………………… 136 Appendices………………………………………………………………………………... 153 DRIVERS OF CHANGE IN MABIS 1 Drivers of Change in Mindfulness- and Acceptance-Based Interventions with Athletes: Investigating the Influence of Dosage, Readiness, and Attitudes Mindfulness, which “has to do with particular qualities of attention and awareness that can be cultivated and developed through meditation” (Kabat-Zinn, 2003, p. 145), is associated with a range of psychological benefits (Keng et al., 2011). Due to the positive outcomes connected to the cultivation of mindfulness, interest in the construct and practice among sport, exercise, and performance psychology (SEPP) researchers and practitioners has grown tremendously in the past two decades. Systematic reviews in SEPP suggest that mindfulness may confer benefits for sport participants, including heightened levels of mindfulness and flow, and reductions in sport anxiety (Noetel et al., 2019; Sappington & Longshore, 2015), with less robust evidence suggesting that mindfulness- and acceptance-based interventions (MABIs) can directly benefit sport performance (Bühlmayer et al., 2017). Although many professionals in SEPP and other related fields have raised concerns about quality and standards of reporting in MABI research (McAlarnen & Longshore, 2017; Noetel et al., 2019; Van Dam et al., 2017), extant literature with athletes evaluating the effectiveness of MABIs is promising. Due to their rising popularity, it is important for both researchers and practitioners to understand with a more nuanced perspective how and under what circumstances such interventions may benefit sport participants. While there is evidence that MABIs lead to change on outcomes related to performance-relevant factors and well-being, much less is known about who changes, and why. In Bühlmayer and colleagues’ (2017) meta-analysis, consisting of nine studies with 290 adolescent and adult sport participants, MABI length ranged from just four weeks to almost two years using a variety of protocols and comparison groups. While it may be reasonable to assume that longer interventions lead to more robust change, that statement is yet to be empirically DRIVERS OF CHANGE IN MABIS 2 validated in SEPP. Investigating a seven-week mindfulness-acceptance-commitment (MAC) intervention (see Gardner & Moore, 2007) compared to an active control group with 18 NCAA Division III female-identified basketball players, Gross and colleagues (2018) suggested that more time to practice mindfulness could have contributed to their findings—which included little change from pre- to post-intervention but significant improvements with large effects (η2 > .19) from post-intervention to 1-month follow-up on measures of emotion regulation, hostility, and substance use (but not mindfulness) for the MAC group. Also notable is that both the MAC group and the active control (a traditional psychological skills training intervention) reported improvements over time in symptoms of anxiety, eating concerns, psychological distress, psychological flexibility, and self-rated sport performance, with large effect sizes (η2 > .17), suggesting that MABIs may be similarly affective as more-commonly integrated interventions (e.g., positive self-talk, goal-setting). Goodman and colleagues (2014) used a similar eight-week MAC intervention with 13 NCAA Division I male-identified basketball players but added an extra 60 extra minutes per week of hatha yoga. MABI participants reported significant improvements on measures of perceived stress and mindfulness with small to moderate effect sizes (d = .26 and .48, respectively) immediately after the intervention. While both Gross et al. (2018) and Goodman et al. (2014) clearly described the amount of in-session mindfulness practice in which participants engaged, the amount of between-session practice was not evident. Josefsson and colleagues (2019) also evaluated the effectiveness of a seven-week MAC intervention compared to an active control group consisting of traditional psychological skills training (PST) with 69 elite athletes in Sweden. MAC participants reported significantly greater improvements compared to controls on measures of mindfulness and emotion regulation, with moderate to large effect sizes (d = .96 and DRIVERS OF CHANGE IN MABIS 3 .74, respectively). Moreover, mindfulness and emotion regulation were found to independently mediate the association between intervention condition and self-rated performance, such that greater increases in mindfulness and decreases in emotion regulation difficulties were associated with higher subjective performance ratings for MAC participants compared to controls. MAC sessions were 50-minutes in length resulting in just under six total hours of intervention dosage, although the degree of home practice was not reported. More condensed MABI have also been evaluated, including a study by Rooks and colleagues (2017). With 100 male-identified NCAA Division I football players, researchers assigned participants to either a 4-week MABI or a time-matched relaxation training control group during the high intensity pre-season period; both interventions included 5.4 hours of instruction and proctored training, and 3.6 hours of assigned home practice over the intervention period. Within-groups analyses indicated that attention decreased, and depressive symptoms, anxiety, and positive affect increased during the intervention—which was described as a high intensity physical training period. Although they failed to reject the null hypothesis in aggregate (i.e., the MABI would promote positive outcomes related to attention and wellbeing), the researchers observed that greater adherence to home mindfulness practice was inversely related to anxiety; moreover, adherence was associated with smaller decreases—and in some cases increases—in attention. Scott-Hamilton and Schutte (2016) similarly observed that competitive adult athletes (Mage = 33.57) who engaged in more home practice between sessions of an MABI improved more on measures of mindfulness, flow, and anxiety with large effects (η2 > .38), though results were not statistically significant—potentially due to a small size (n = 12). Glass and colleagues (2019) also reported that college athletes who engaged in more frequent mindfulness practice reported significant improvements in flow and self-rated sport performance. DRIVERS OF CHANGE IN MABIS 4 Regardless of dosage, the 43 athletes who completed the intervention—a six-week Mindful Sport Performance Enhancement (MSPE) training—reported improvements in flow, mindfulness, life satisfaction, and aspects of sport anxiety, with moderate to large effects (|0.47| < d > |0.81|; Glass et al., 2019). These studies support the idea that dosage could influence MABI outcomes with athletes, though more investigations studying dosage more specifically and as a moderator are needed. The potential dose-response relationship in MABIs has been explored more explicitly outside of sport with varied populations. A review by Parsons and colleagues (2017) found that 28 studies (out of 43) reported positive associations between amount of home mindfulness practice (i.e., dosage) and outcomes, indicating significant pooled results. Reported effects, though significant, were small (r = .26). Although these data indicate that dosage may be related to outcomes, Parsons et al. (2017) reported evidence for publication bias as well as broad variability in the amount of practice across studies. In a sample of 174 adults (Mage = 47.05) who had been referred to an eight-week Mindfulness-Based Stress Reduction (MBSR) group based on their clinical diagnoses, Carmody & Baer (2008) observed that between-session mindfulness practice was associated with reductions in unhelpful psychological symptoms and stress and improvements in wellbeing, which were mediated by increases in mindfulness. They also found that specific practices were correlated with different reported outcomes (e.g., positive association between minutes practicing body scans and psychological wellbeing). In a cross-section of 1,668 meditators (Mage = 45) across various traditions of practice, Bowles et al. (2022) observed a non linear effect of lifetime meditation practice on outcomes related to psychological wellbeing; specifically, the largest effects of meditation were observed in the first 500 hours practice before plateauing. Though causal claims are impossible, these data further suggest that dosage is a DRIVERS OF CHANGE IN MABIS 5 useful avenue to explore particularly early in one’s practice. Little attention has been placed on this issue in the SEPP literature, and it is unknown if these effects will translate to non-clinical samples. Related to, yet distinct from, research with sport performers is the growing body of MABI and dosage research with tactical populations (e.g., EMS, military). Stanley and colleagues (2011) conducted an MABI with pre-deployment marines—following a structured protocol that resembled a shortened MBSR protocol—and observed that more mindfulness practice between intervention sessions contributed to significant increases in mindfulness; mindfulness was also inversely associated with perceived stress among the group of marines that engaged in more mindfulness practice. Jha et al. (2017) observed that mindfulness training emphasizing practice of specific exercises (as opposed to didactic instruction) contributed to a protective effect against working memory degradation in a military cohort including 80 soldiers. The body of work produced by Amishi Jha and her colleagues suggests that ~12 minutes per day of mindfulness practice between four and eight weeks is a threshold at which mindfulness practice begins to produce salutary effects related to cognitive functioning and stress (Jha et al., 2017, Stanley et al., 2011, Stanley, 2014). This number has not been confirmed in SEPP studies of MABIs, but was partially replicated by Basso et al. (2019) in a sample of healthy adults between the ages of 18 and 45 who had no previous meditation experience. Compared to control group participants who listened to a daily 13-minute podcast, participants engaging in 13 minutes per day of meditation (i.e., breathing meditation and body scan) reported significant reductions in mood disturbances and emotion regulation difficulties, and improvements on a range of cognitive functioning tasks. (e.g., Stroop task, Mnemonic Similarity Task). Future research would benefit from replication studies with more targeted samples—like sport participants. It is DRIVERS OF CHANGE IN MABIS 6 also important to note that Dr. Jha’s work has primarily been conducted with tactical populations using an MABI that is slightly different than MABIs typically integrated with athlete populations (e.g., MSPE, MAC). Up to this point, MABIs have been discussed more generally, but it is important to note that the structure, content, and delivery of MABIs differs depending on the program; further study is needed to compare opposing MABI training programs to determine potential differential effects. In addition to the possible influence of dosage, readiness to engage in MABIs is another possible driver of change—which also may be related to dosage such that readiness may impact the degree of engagement, which ultimately could influence outcomes. In the context of PST, readiness has been assessed via The Transtheoretical Model (TTM) of behavior change which proposes that individuals progress through different stages of change as they work toward adopting or extinguishing a specific behavior (Prochaska & DiClemente, 1984). From early to later readiness, the stages of change include precontemplation, contemplation, preparation, action, maintenance, and termination (Prochaska & DiClemente, 1984). TTM, which includes the aforementioned stages of change as well as specific processes of change associated with movement between the different stages, has been used as a theoretical model with various populations and presenting concerns that people wish to change; some of these presenting concerns include dependence on alcohol, tobacco, or other substances, unhealthy exercise and health behaviors, and engagement in psychotherapy (Krebs et al., 2018; Prochaska et al., 2008). Some research in SEPP has used TTM to understand engagement in sport psychology consulting and use of psychological skills, though the evidence base is small. For example, Leffingwell and colleagues (2001) found circumstantial evidence suggesting that stage of change as measured by DRIVERS OF CHANGE IN MABIS 7 TTM predicted future mental skills consultation—participants in the action stage were more likely than contemplators and pre-contemplators to seek consultation at follow-up. Keeler and Watson (2009) also found that no pre-contemplators sought individual sport psychology consultation after a five-day intervention period (consisting of team-based sport psychology workshops) with their team of 31 elite, female-identified rugby players in the U.S. Though readiness has been used sparingly to understand how participants may engage in interventions in the context of PST, it has not been used as a moderator to predict if and how participants engage with and change following PST interventions—and has not been used at all to understand change following MABIs in sport. Outside of sport, Krebs and colleagues (2018) observed in the clinical literature that pre-psychotherapy stage of change might predict outcomes; specifically, later pre-treatment stage of change was associated with better post treatment outcomes. Therefore, it is reasonable to predict that later stage of change may predict more engagement in, and better outcomes following, an MABI with athletes. While quantitative studies provide details about possible MABI effects or mechanisms through which they may influence athletes, qualitative investigations provide another perspective on athlete experiences with and attitudes toward MABIs. Baltzel et al. (2014) interviewed seven female-identified NCAA Division I soccer players who participated in a 12-session Mindfulness Meditation Training for Sport (MMTS) intervention consisting of 30-minute modules. Many participants reported benefits related to the training, while also noting that they were hesitant to participate in the training at first and found meditation more difficult to engage in at the start of the intervention. Interviewees experienced a positive shift in their attitudes as they practiced more and were able to connect the practice to sport participation. This finding could suggest that pre-intervention attitudes or readiness influenced engagement or outcomes to some degree, and DRIVERS OF CHANGE IN MABIS 8 that attitudes and readiness may change through an MABI. Cote and Colleagues (2019) similarly interviewed nine collegiate tennis players following an MMTS 2.0 intervention, and while they observed many benefits in practicing mindfulness, they also observed some associated difficulties and discomfort. This important perspective is less often reported in the MABI literature in sport, which tends to focus more on the benefits of mindfulness practice than drawbacks or negative experiences. Research investigating attitudes toward sport psychology services suggests that some sport participants are still hesitant to engage in sport psychology consultation (Martin et al., 2012), though athletes with previous experience to sport psychology services generally have more positive attitudes toward sport psychology (Martin et al., 2005). It is thus reasonable to expect that not all athletes would be open to engaging in an MABI. Understanding how readiness and attitudes potentially interact to influence outcomes following MABIs with athletes could clarify questions about for whom MABIs are more effective. It would also be useful to understand how athlete readiness and attitudes related to mindfulness changes over the course of an intervention. These issues are of particular salience in SEPP research because randomization often occurs at the team level, and interventions are delivered to groups. Though some studies have explored the role that dosage and attitudes could play in influencing outcomes, no specific study in the MABI and sport literature has investigated the explanatory power of these variables either as predictors or moderators. Therefore, the present study has three primary aims. The first aim is to replicate previous findings associated with change following an MABI—specifically related to flow, psychological distress, mindfulness, emotion regulation, performance, and other constructs empirically linked to MABIs (Glass et al., 2019; Josefsson et al., 2017; Kostrna & D’Addario, 2022)—using a comparison group and a manualized protocol (Mindful Sport Performance Enhancement; Kaufman et al., 2018). The DRIVERS OF CHANGE IN MABIS 9 second aim is to understand if stage of change regarding engagement in mindfulness training (i.e., readiness) and attitudes toward sport psychology impact change during an MABI. The third and final aim of the present study is to explore the potential associations between readiness, dosage, and outcomes, and specifically whether dosage (i.e., between-session practice of mindfulness exercises) and attitudes toward sport psychology moderate any associations between readiness and outcomes. Research Design Method To address the aims of the study, a longitudinal, non-randomized control group design was utilized to evaluate the immediate and short-term follow-up effects (i.e., six weeks) of an MABI. Quantitative outcomes of interest in the present study included flow, psychological distress (i.e., depression, anxiety, and stress), mindfulness, emotion regulation, attitudes toward sport psychology, self-rated sport performance and enjoyment, stage of change as it relates to engagement in mindfulness practice (referred to as “readiness” from this point forward), and life satisfaction. Another relevant outcome was the amount of between-session mindfulness practice (referred to as “dosage” of mindfulness) in which participants engaged—measured by weekly self-report. Sampling and Recruitment Convenience sampling was utilized to recruit study participants. Specifically, 28 head coaches at two NCAA Division II and III universities in the Appalachian region were contacted in the fall of 2021 via email and offered mindfulness training for their teams in their spring 2022 preseason or offseason periods (i.e., January-May of 2022) in one of two six-week timeframes: either mid-January to late-February, or late-February to early April. Additionally, the first author DRIVERS OF CHANGE IN MABIS 10 and one research associate attended athletics department staff meetings at both universities to share details about the intervention and research opportunity. Research participation was introduced as a voluntary component, and athletes would be able to opt out of the research and still participate in the MABI. Five coaches from two universities demonstrated interest, and ultimately four coaches (one men’s team and three women’s teams) agreed to have their teams participate. Though randomization to condition (i.e., intervention or waiting-list (WL) control) was initially communicated as a requirement to their participation in recruitment messages, all four coaches said that only one of the two timeframes was feasible, so randomization was not possible. Thus, all teams were assigned to the intervention or WL groups based on availability. Participants Sixty-five student-athletes (SAs) from Acrobatics and Tumbling (Acro; N = 22), Women’s Volleyball (Volleyball; N = 13), Men’s Soccer (MSOC; N = 13), and Women’s Soccer (WSOC; N = 17) initially consented to research participation, though there was a 12.31% attrition rate during the intervention period and a 26.15% attrition rate between pre-intervention and follow-up; 57 SAs across all four teams completed MSPE and pre- and post-intervention assessments, and 48 SAs completed MSPE as well as pre-, post-, and follow-up assessments. The sub-sample that completed both pre- and post-intervention assessments (i.e., n = 57) consisted of 13 male-identified SAs and 45 female-identified SAs, with a mean age 19.36 (SD = 1.10). The sub-sample that completed pre-, post-, and follow-up data (i.e., n = 48) consisted of eight male identified athletes and 40 female-identified athletes, with a mean age of 19.44 (SD = 1.15). Most of the participants who completed the intervention identified as Caucasian (n = 49). A fraction of participants practiced mindfulness or meditation at the start of the MABI (9.23%), though a larger number had been exposed to sport psychology in some capacity (23.08%). Volleyball, DRIVERS OF CHANGE IN MABIS 11 MSOC, and WSOC competed for an NCAA Division III institution, and Acro competed for an NCAA Division II institution. Assessments Background Questionnaire (Appendix A) A ten-item background questionnaire assessing demographic data was included before the first round of data collection. Participants were asked to provide information related to age, gender identity, ethnicity, grade level, sport history, and experience with mental skills training and mindfulness. Because engagement in meditation has been linked with trauma re experiencing (Britton et al. 2021; Farias et al., 2020), two trauma screening measures were included on the background questionnaire to flag participants who were at-risk for adverse experiences: participants were asked to respond to a close-ended (i.e., yes or no) question inquiring if they had a history of trauma. An abbreviated, two-item PTSD Checklist-Civilian (PCL-C; Lang & Stein, 2005) was used as a PTSD screening tool. Though normed when the DSM-IV was still in use, Lang and Stein (2005) observed that the two-item measure was strongly correlated with the original 17-item PCL-C measure (r = .89) in use at the time. The two items also included in the trauma re-experiencing sub-scale of the current 20-item PTSD Checklist for DSM-V assessment (Blevins et al., 2015). Lang et al. (2012) commented that the two-item PCL-C can serve as an effective screening tool, though they recommend using the six item PCL or the full version for symptom monitoring (which was not done in the present study). The Cronbach’s alpha value for PCL-C items used in the present study was .86. Cognitive and Affective Mindfulness Scale – Revised (CAMS-R; Appendix B) Feldman and colleagues (2007) created the 12-item CAMS-R as a multi-dimensional assessment of mindfulness, including four first-order factors: attention, present focus, awareness, DRIVERS OF CHANGE IN MABIS 12 and acceptance. Participants respond to each item on a four-point Likert scale ranging from one (“rarely/not at all”) to four (“almost always”), yielding one total score; higher scores indicate higher levels of mindfulness. A CFA, conducted by Feldman et al. (2007), indicated that the data fit the hypothesized model, χ2(50) = 110.58, p < .0001, RMSEA = .064, SRMR = .052, CFI = .92. Evidence of convergent validity was observed through strong correlations with existing mindfulness measures (i.e., Freiburg Mindfulness Inventory, Mindful Attention and Awareness Scale), with correlation coefficients greater than .50 (Feldman et al., 2007). With college students, Baer and colleagues (2006) reported acceptable internal consistency of the CAMS-R (α = .81) and found that the CAMS-R was moderately and positively associated with three other commonly used mindfulness measures (.51 < p > .67; Mindful Attention Awareness Scale, Freiburg Mindfulness Inventory, and Kentucky Inventory of Mindfulness Skills, respectively). Internal consistency reliability from CAMS-R data the present study was acceptable at all three time points. See Table 1 for a list of Cronbach’s alpha values for all measures included in the present study. Depression, Anxiety, and Stress Scales (DASS-21; Appendix C) The 21-item DASS-21, used to assess three dimensions of psychological distress, was adapted by Lovibond and Lovibond (1995) from the original 42-item measure (Lovibond & Lovibond, 1993). Three seven-item subscales assess participant levels of depression, anxiety, and stress on a four-point Likert scale ranging from zero (“did not apply to me”) to three (“applied to me very much, or most of the time”). Higher scores on each subscale indicate higher levels of psychological distress, and a total score is taken and multiplied by two to correspond with scores on the original DASS measure. A CFA conducted by Henry and Crawford (2005) indicated that this 21-item measure of psychological distress had adequate factor loadings, with a DRIVERS OF CHANGE IN MABIS 13 mean loading of .60 on the general factor and a mean loading of .34 on specific factors. Though some individual factor loadings were low (i.e., below the .40 convention), DASS-21 subscale scores demonstrated evidence of convergent validity with other commonly used inventories (e.g., Beck Depression Inventory, Beck Anxiety Inventory; Henry and Crawford, 2005). Henry and Crawford (2005) also reported acceptable Cronbach’s alpha estimates in their study of a non clinical sample of adults in the UK, with values ranging from .82 to .93. Like Henry and Crawford, Osman and colleagues (2012) observed that some individual items loaded onto individual factors below the .40 guideline (Kline, 2016). Because second order factor loadings were all above .60, and because the total DASS-21 score was moderately to strongly associated with other measures of psychological distress (e.g., Beck Anxiety Inventory, Beck Depression Inventory-II, respectively), Osman et al. (2012) recommend utilizing a total score. Both sub scale scores and a total score were calculated and utilized in analyses in the present study. Difficulties in Emotion Regulation Scale – Short Form (DERS-SF; Appendix D) The 18-item DERS-SF was adapted by E. A. Kaufman et al. (2015) from the original, well-validated 36-item DERS (Gratz & Roemer, 2004) assessing emotion regulation difficulties. The measure yields one total score and scores on six, three-item subscales of emotion regulation strategies, non-acceptance, impulse control, goals, awareness, and clarity where higher scores indicate more emotion regulation difficulties. Participants respond to each item on a one (“almost never”) to four (“almost always”) Likert scale. A CFA with a sample of 797 American college students indicated acceptable data fit to the hypothesized model, RMSEA = .05, TLI = .96, SRMR = .04; Cronbach’s alpha estimates for each subscale and total score in the study by E. A. Kaufman et al. (2015) all exceeded .70, demonstrating acceptable reliability, and correlations DRIVERS OF CHANGE IN MABIS 14 coefficients between the DERS-SF and DERS ranged from .90 to .97—indicating strong associations. Mindfulness Dosage and Between-Session Practice Assessment (Appendix E) Mindfulness dosage (i.e., amount of mindfulness practice between intervention sessions) was assessed at seven different time points: before sessions two through six, one week after the final session, and 6 weeks after the conclusion of the intervention. Prior to MABI sessions two though six, participants were asked to complete either a paper/pencil or Qualtrics questionnaire assessing how many times they completed the home practice exercises as described by Kaufman et al. (2018; see appendix L), as well as the type and duration (e.g., YouTube meditation for five minutes) of any other mindfulness practice in which they engaged above and beyond the recommended home practice. Three markers of dosage were thus derived: total dosage (minutes per day) between pre- and post-intervention, total dosage between pre-intervention and six-week follow-up, and percentage of prescribed home practice completed by participants between pre- and post-intervention. Because adverse effects can occur during or after mindfulness practice, particularly when interventions are not tailored to meet the needs of specific populations (Farias et al., 2020; van Dam et al., 2018), researchers have suggested that it may be best practice to actively monitor for negative experiences as to mitigate harm (Britton et al., 2021). For monitoring purposes, participants were asked after the dosage assessment on a yes/no question whether they had experienced an adverse effect during mindfulness practice between sessions. If they had, they were invited to describe the negative experience and posed with a yes/no question assessing whether they would like to be referred to support services. Open-ended questions also assessed barriers and/or benefits associated with home practice. DRIVERS OF CHANGE IN MABIS 15 Program Evaluation Questionnaire (PEQ; Appendix F) The seven-item post-intervention PEQ—derived from previous investigations of the intervention under study (i.e., Mindful Sport Performance Enhancement; Glass et al., 2019)— was used to understand participant experiences with the program. On the assessment, participants were first asked to indicate the number of intervention sessions they attended. They were then invited to rate their perceived success of the program in helping them make improvements in flow, anxiety, focus, nonjudgement, awareness, and emotion regulation on a one (“not helpful at all”) to seven (“extremely helpful”) Likert scale. These questions were followed by an assessment of how confident participants were that they would continue utilizing mindfulness in sport and everyday life. Finally, open-ended responses assessed what they found most challenging about the intervention, what benefits they felt they received from engaging in the training, and whether they consented to being contacted for a follow-up interview. Readiness University of Rhode Island Change Assessment (URICA; Appendix G). Readiness to engage in mindfulness practice was assessed by adapting a version of the URICA used by Massey et al. (2015), who evaluated the utility of their adapted version to understand readiness in the context of traditional psychological skills training with college athletes. The original URICA (McConnaughy et al., 1983) was developed as a 32-item measure to assess behavior change using the Transtheoretical Model (TTM). Massey et al. (2015) used a variation of Leffingwell et al.’s (2001) version of the URICA as a 12-item measure, and found that a four factor (pre contemplation, contemplation, action, maintenance) structure demonstrated acceptable model fit, RMSEA = .078, CFI = .92. Participants are asked to respond to comments on a five-point Likert scale ranging from one (“strongly disagree”) to five (“strongly agree”), with three questions DRIVERS OF CHANGE IN MABIS 16 corresponding to one of four separate factors. The highest sub-scale score indicates the stage of readiness (e.g., if participants score highest on the pre-contemplation sub-scale, the participant is labelled as such). Though the URICA provides continuous data, it was treated as categorical for analyses (i.e., participants fell into one of four possible stages depending on the highest subscale score). The language of the URICA was modified to assess readiness to practice mindfulness as opposed to readiness to use of mental skills (e.g., “I have used mindfulness for at least six months and plan to continue working on being mindful” was modified from the original “I have used the mental skills I have learned for at least 6 months and plan to continue working on them”). Cronbach’s alpha values for time one subscales in the present study were .68, .70, .88, and .90 for precontemplation, contemplation, action, and maintenance, respectively. Single-Item Readiness Assessment. A second, single-item assessment of readiness used by Minkler et al. (2022) was also included. The item includes a brief description of mindfulness, after which participants are invited to indicate one of five responses that best categorizes their relationship to mindfulness. The five responses are based on one of five stages of change as described by TTM. This item was included on the Background Questionnaire (Appendix A), and it was primarily used to help with categorization if participants had reported equal scores on multiple sub-scales of the URICA. For example, if a participant reported equal scores on the contemplation and action sub-scales and indicated that they were in contemplation on the single item readiness measure, then they were categorized as contemplators given that there was more evidence for that stage classification. Satisfaction with Life Scale (SWLS; Appendix H) The five-item SWLS (Diener et al., 1985) assesses global life satisfaction on a seven point Likert scale ranging from one (“strongly disagree”) to seven (“strongly agree”); higher DRIVERS OF CHANGE IN MABIS 17 scores indicate greater life satisfaction. In the original validation study, Diener et al. (1985) found that the SWLS demonstrated moderate to strong correlations with other assessments of well-being (r > .30). In summarizing the updated psychometric information from over two decades of research, Pavot and Diener (2008) reported a high degree of internal consistency reliability across several studies (Cronbach’s alpha levels greater than .80). Divergent validity has been demonstrated via strong, significant inverse correlations between the SWLS and clinical measures of distress (e.g., BDI, Symptom Checklist-90; Pavot & Diener, 2008). Short Dispositional Flow Scale-2 (SDFS-2; Appendix I) The SDFS-2, adapted by Jackson and colleagues (2008) from the original 36-item DFS, includes nine items assessing each of the nine elements of flow as described by Csikszentmihalyi’s (1990) conceptualization. Participants are asked to rate how often they experience each component of flow during their sport on a five-point Likert scale from one (“never”) to five (“always”). One total score is reported, with higher scores indicating more frequent flow experiences. There is good evidence for reliability and validity of this measure: through confirmatory factor analysis (CFA), Jackson et al. (2008) provided evidence of validity and internal consistency reliability, demonstrating that that the nine-item measure had acceptable model fit, RMSEA = .08, CFI = .95, SRMR = .04. Moreover, Martin et al. (2006) reported an acceptable Cronbach’s alpha estimate of .82. Sport Performance, Enjoyment, and Expectancy Effects (Appendix J) Self-rated sport performance was assessed with one-item on a 1 one (very poor) to 9 (very good) Likert Scale. Josefsson and colleagues (2019) assessed sport performance in a similar fashion, although they utilized a 10-point Likert scale. On the same nine-point Likert Scale, participants are also asked to rate their sport enjoyment. Moreover, to assess pre DRIVERS OF CHANGE IN MABIS 18 intervention expectancy effects, participants were also asked to assess how they expected to rate their performance and enjoyment after the MABI. Sport Psychology Attitudes – Revised Form (SPA-R; Appendix K) The 25-item SPA-R, developed by Martin and colleagues (2002), assesses athlete attitudes toward sport psychology services on a seven-point Likert scale from one (“strongly disagree”) to seven (“strongly agree”) with four sub-scales: stigma tolerance, confidence, personal openness, and cultural preference. Higher scores indicate more positive attitudes toward sport psychology and the utilization of services on all sub-scales except stigma tolerance—where lower scores indicate higher tolerance of stigma (and therefore better attitudes toward sport psychology). A CFA with over 1,000 athletes from the United States, Germany, and British athletes was conducted by Martin et al. (2002), testing a four-factor solution, which indicated acceptable fit indices, RMSEA = .06, CFI = .96, SRMR = .05. With a similar population of athletes from the United States, Germany, and Great Britain, Martin et al. (2005) reported Cronbach alpha values of .82 and .84 for confidence in sport psychology consulting and stigma tolerance, respectively; for personal openness and cultural preference, alpha values were below the .70 guideline at .61 and .66, respectively. A recent study by Ballesteros and colleagues (2019) using the SPA-R with high school athletes also reported low Cronbach alpha values on the personal openness (.56) and cultural preference (.60); due to the repeatedly low Cronbach alpha values, those subscales were not included; only the confidence in sport psychology consulting and stigma tolerance subscales were used (15 items in total). Compared to previously studied samples of college student athletes (i.e., Martin et al., 2005), athletes at baseline in the current study reported higher confidence in sport psychology DRIVERS OF CHANGE IN MABIS 19 and less stigma (5.5 compared to 4.9, and 2.00 compared to 2.46 on confidence and stigma tolerance, respectively). Intervention Participants engaged in a 6-week Mindful Sport Performance Enhancement (MSPE) training, using the protocol created by Kaufman and colleagues (2018). Each session was 60 minutes in duration. In this structured yet adaptable MABI that includes elements from Jon Kabat-Zinn’s Mindfulness-Based Stress Reduction and Mindfulness-Based Cognitive Therapy (MBCT), sport participants are taught mindfulness both didactically and experientially in weekly, hour-long sessions. Exercises are initially sedentary in nature (e.g., diaphragmatic breathing, sitting meditations) and evolve to include practices during which mindfulness is practiced in motion (i.e., mindful walking, mindful hatha yoga). The culminating practice is a sport-specific mindfulness exercise. The sport-specific meditation is typically practiced in the final two sessions, but the protocol had to be adapted for MSOC and WSOC because of weather and availability of space—therefore the sport meditation for those teams was only practiced in session five and discussed (but not practiced) in session six. In addition to various mindfulness practices, a discussion component is also included in each session. Prescribed home practice includes roughly 377 minutes between weeks one through five (~11 minutes per day), with no practice assigned after the final session. See Appendix L for an outline of each session, with prescribed home practice included. Procedure Coaches were contacted about receiving a free sport psychology workshop before Institutional Review Board (IRB) approval was obtained. After teams agreed to participate and schedules were finalized, final IRB materials were submitted, which included documents signed DRIVERS OF CHANGE IN MABIS 20 by each coach agreeing to have their teams participate and recognizing the optional nature of research participation. Once IRB approval was received, the first author held informational meetings with each team, where participants were informed about the conditions of research participation and that they could engage in the MABI without participating in the research component. The initial MSPE teams (Acro and Volleyball) were given details about MSPE and information about mindfulness at the informational meeting, including the range of experiences they might have while engaging in mindfulness practices. In consultation with the counseling centers at each institution, referral plans were also established based on institutional policies. Participants were given information about how to seek help if they had a negative or adverse experience; weekly dosage assessments served as regular monitoring for adverse experiences needing clinical intervention. To protect against expectancy effects and limit the degree to which they could learn about and potentially begin practicing mindfulness before the intervention, WL control participants were given less information about the MABI at time one. Instead, at the initial informational meeting, control participants were told they would be engaging in a sport psychology mental skills training program during their off-season training period (which was set to begin six weeks later), and that we would be collecting pre-intervention data at two time points and comparing that data to teams who would be engaging in the same intervention before them. One week before they were to engage in the MABI, WL control participants were given details about the nature of the intervention (as described in the previous paragraph) and provided with another opportunity to opt out. After describing the voluntary research component and the fact that the intervention leader would be blind to those who agreed to participate and those who did not agree, the first DRIVERS OF CHANGE IN MABIS 21 author left the room for participants to review and choose to sign (or not sign) the informed consent document. After reviewing the consent document, participants were invited to complete the battery of pre-intervention assessments described previously. The informed consent document served as the cover page of the questionnaire booklets, which were placed in individual envelopes and sealed by each athlete upon completion. Each participant created a six digit identification number based on the last four digits of their cell-phone numbers and the first two digits of their home ZIP code for anonymization. All identifying information was removed from questionnaire booklets by the senior author, who recorded names and identification numbers in a Microsoft Excel File to which the first author did not have access (to keep the intervention leader blind to research participation). De-identified questionnaires were kept in a locked file cabinet. The questionnaires were completed by initial MSPE participants at three time points (pre intervention, post-intervention, six-week follow-up) and four times by WL control participants (pre-intervention 1, pre-intervention 2, post-intervention, six-week follow-up). Questionnaires were completed via pencil and paper at times one through three, and via Qualtrics at time four (as WL control participants had gone home for the semester). The questionnaires were counterbalanced using a Latin Square design at each time point. Following the intervention, participants were asked to complete the same battery of assessments minus the background questionnaire but including the PEQ. Immediately preceding sessions two through six, participants were asked to complete the dosage and between-session practice assessment via paper and pencil or Qualtrics; the intervention leader left the room during that time. Because the initial MSPE group concluded their training in the middle of the semester, one of the conditions recommended by initial MSPE group coaches was that follow-up meetings DRIVERS OF CHANGE IN MABIS 22 be scheduled after the conclusion of the formal MSPE program. Kaufman et al. (2018, p. 14) recommend that practitioners avoid “parachuting in”—in other words, dropping in for the duration of the intervention and then ceasing contact upon program completion. For meaningful integration of mindfulness into the culture of the team, according to Kaufman et al. (2018), the MSPE protocol is meant to set the foundation for continued future contact and engagement. Considering the recommendations of Kaufman et al. (2018) and meeting the needs of the coaches in the study, initial MSPE teams had weekly follow-up meetings ranging in duration from 30-60 minutes where sedentary MSPE exercises were practiced, and discussions of home practice and application took place. These follow-up meetings took place between post intervention and follow-up data collection, and they were voluntary. Because WL control teams concluded the training at the end of their semesters, follow-up meetings were not feasible. See Appendix L for a description of MSPE and follow-up sessions. Consulting Orientation, Experience, Education, and Positionality The first author, who also served as the intervention leader, has been engaged in supervised mental performance consulting for nearly five years, having worked as a collegiate coach prior to pursuing formal education in SEPP. He also currently works as a mental health counseling intern, providing individual and group psychotherapy to emerging adults in a college counseling center and a private practice. His consulting theoretical orientation is largely humanistic and person-centered, though he draws heavily on mindfulness- and acceptance-based interventions and principles (e.g., Acceptance and Commitment Therapy, Dialectical Behavior Therapy, Mindfulness-Based Cognitive Therapy) and Polyvagal Theory (Porges, 2001) in his applied work and conceptualizes cases through the lens of the Adaptive Information Processing (AIP; Shapiro, 2018) model. Crane and colleagues (2012) have commented on the need to DRIVERS OF CHANGE IN MABIS 23 develop a certain level of competence with regards to training and education for mindfulness teachers; to that end, the first author has taken formal mindfulness courses, pursued and completed MSPE teacher training, consulted with and continues to seek supervision in both his delivery and personal practice of mindfulness, and has maintained a consistent personal mindfulness practice for over five years. Moreover, the first author and the senior author have been engaged in mindfulness research, applied work, and practice for nearly three decades combined. The intervention leader’s experiences all contribute to an important perception and expectation about what might be expected to occur during and after mindfulness training with athletes. His position as a mindfulness researcher, applied practitioner, teacher, and student of mindfulness and Buddhist philosophy in general colors the lens through which he and the research team have approached this study and the data that has been produced. To balance the degree to which these experiences might influence data analysis and interpretation, the project includes authors with expertise in SEPP applied practice and clinical psychotherapy as well as an external author from another field (i.e., Educational Psychology). Including these differing perspectives was intentional in an attempt view the data and results from a less biased perspective and compartmentalize personal values as much as possible. A postpositivist stance was adopted in the data analysis and interpretation, which posits that an objective reality exists but can only be imperfectly understood (Ponterotto, 2005), and attempts at triangulation were sought by including multiple perspectives and bracketing of personal expectations and biases (first becoming aware of and documenting such biases through reflexive journaling). DRIVERS OF CHANGE IN MABIS 24 Data Analysis In addition to computing descriptive statistics regarding baseline characteristics, data were analyzed in four separate approaches. First, to assess between-group change over time (i.e., MSPE vs. WL control), a series of 2x2 and 2x3 mixed repeated-measures analyses of covariance (RM ANCOVAs) were conducted using SPSS (IBM, 2020). Time and condition (MSPE or WL control) served as independent variables (IVs), and both attitudes SPA-R sub-scales served as covariates (unless the independence of the covariate assumption was violated, indicated in Tables 3 and 4). Dependent variables (DVs) included flow, psychological distress (i.e., depression, anxiety, and stress), mindfulness, emotion regulation difficulties (and associated sub scales), life satisfaction, sport performance, and sport enjoyment. Sport psychology attitudes were also examined as DVs in RM analyses of variance (ANOVAs) For sport performance and enjoyment RM ANCOVAs, post-intervention expectations were also included as covariates. Second, to investigate the potential effects that readiness had on DVs, a series of within groups RM ANCOVAs were conducted in which readiness served as the IV. Pre-intervention, post-intervention, and 6-week follow-up data from all participants regardless of condition was combined across three time points. Due to low numbers in most of the readiness conditions, readiness was condensed from four stages to two; therefore, participants fell into either high (action or maintenance) or low (contemplation or pre-contemplation) readiness to preserve power. RM ANCOVAs explored differential effects of both time one and time two readiness on outcomes over time, with sport psychology attitudes modelled as covariates. Third, to explore moderation effects of attitudes toward sport psychology and dosage on the potential relationship between readiness and outcomes, a series of bivariate Pearson correlations, independent samples t-tests, and regressions using the PROCESS macro (Hayes, DRIVERS OF CHANGE IN MABIS 25 2022) were conducted in SPSS (IBM, 2020). Descriptive statistics regarding dosage during the intervention were calculated, as well as percent of home prescribed home practice completed by participants. Bivariate Pearson correlations explored associations between sport psychology attitudes and dosage, and between dosage and change scores on outcomes. Independent samples t – tests were used to examine potential differences in dosage depending on readiness and group (i.e., initial MSPE or WL control). Finally, the PROCESS macro was used to explore moderation effects of dosage and attitudes. Finally, PEQ ratings of program success were explored with descriptive statistics; moreover, potential differences in ratings of program success depending on readiness and attitudes toward sport psychology were probed using independent samples t – tests and bivariate Pearson correlations, respectively. Qualitative data assessing benefits, barriers, and challenges faced throughout the intervention was coded using inductive thematic analysis (Braun et al., 2016) and influenced by the coding used by Minkler and colleagues (2022). Results Descriptive Statistics and Baseline Characteristics Independent samples t-tests were conducted at baseline (N = 65) to determine if any differences existed between conditions on DVs. The initial MSPE group, compared to the WL control group, reported significantly higher confidence in sport psychology services, t(63) = 2.28, p < .05), and less stigma associated with sport psychology service provision (though not statistically significant) at time one, with small effects. There was also a significant difference between the initial MSPE group and WL control group on the DASS-21 sub-scale of depression, t(63) = 2.04, p < .05, such that MSPE participants reported significantly higher depression scores than control participants. There were no other statistically significant between-groups differences DRIVERS OF CHANGE IN MABIS 26 at baseline on outcomes (see Table 1). For readiness frequencies at times one through three, see Table 2. Regarding dosage, initial MSPE participants practiced MSPE exercises for an average of 6.54 minutes per day (SD = 4.84) between time one and time two and 5.17 minutes per day (SD = 4.00) between time one and time three; WL control participants—once they had completed the intervention—practiced MSPE exercises for an average of 6.67 minutes per day (SD = 5.70) between time two and time three and 5.10 minutes per day (SD = 5.67) between time two and time four. There were no significant differences in amount of practice between groups. With the overall sample (N = 65), a series of within-groups Pearson correlations also probed the degree to which expectancy effects and attitudes toward sport psychology were associated. There were significant inverse correlations between stigma tolerance and expected improvements in both performance and enjoyment (r = -.59 and -.50, respectively), such that higher ratings of expected post-intervention performance and enjoyment were associated with less stigma. Moreover, there was a significant, positive association between expected improvements in sport enjoyment and confidence in sport psychology (r = .32). See tables 8, 9, and 10 for means, standard deviations, and correlations among primary outcomes at each time point. Between-Groups Differences: Time 1 and Time 2 A series of 2 x 2 repeated measures analyses of covariance (RM ANCOVAs) were conducted to compare change between time 1 and time 2 on DVs between conditions. The sub sample supporting these analyses was 57. Due to statistically significant differences between groups at baseline on attitudes toward sport psychology (i.e., confidence in sport psychology services and stigma), they were included as covariates in these analyses. See Table 3 for RM ANCOVA results and estimated marginal means, including notations indicating when certain DRIVERS OF CHANGE IN MABIS 27 assumptions were violated (the independence of the covariate assumption was violated on analyses of anxiety, depression, DERS-SF impulse control, DERS-SF awareness, and sport enjoyment; covariates that violated the assumption were thus removed). There were no significant condition-by-time effects on flow, anxiety, stress, and life satisfaction, and effect sizes were negligible. There were also no significant condition by time effects on sport enjoyment and mindfulness, though effect sizes were small to moderate, respectively; the MSPE group reported non-significant improvements in both sport enjoyment and min