The Psychology of Athletic Tapering in Sport: A Scoping Review

Taper is a common training strategy used to reduce fatigue and enhance athletic performance. However, currently, no review has summarised what psychological research has been conducted examining taper, what this research shows and what future research needs to be undertaken to extend the field. Consequently, a scoping review was conducted with three aims: (a) to determine the characteristics of psychological research examining taper, (b) to summarise psychological research collected during taper with adult athletes and coaches, and (c) to identify gaps in psychological research examining taper. Forty-eight articles were identified following an exhaustive search strategy and charted following scoping review guidelines. Results showed most research was quantitative, used a longitudinal design, was conducted in swimming, triathlon, cycling or across multiple sports, and used a university-, regional- or national-level male athlete sample. Eight themes were developed to summarise the research: Mood, Perception of Effort, Perceived Fatigue and Wellness, Recovery-Stress, Taper as a Stressor, Stress Tolerance, Psychological Preparation and Cognitive Functioning. Additionally, four research recommendations were identified: (a) conducting exploratory research that examines the impact taper has on athletes’ and coaches’ competition preparation and stress experience, (b) asking more advanced psychological questions and conducting multi-disciplinary research, (c) including a more diverse participant sample in studies and (d) examining the impact of psychological interventions during taper. Overall, this scoping review has highlighted the limited research examining the psychology of taper and the need for focused research that asks more complex questions across diverse populations. Supplementary Information The online version contains supplementary material available at 10.1007/s40279-022-01798-6.


Introduction
Taper refers to a progressive reduction in training load prior to athletic competition aiming to reduce fatigue while maintaining/enhancing training adaptations [1]. This reduction in fatigue and maintenance/enhancement of training adaptions has a substantial impact on athletic performance, normally leading to improvements of 2-3% [1]. Although these changes are marginal, in elite sport, they often differentiate between finishing inside or outside medal positions during major sports events [2]. Consequently, understanding and optimising taper is key to athletic success and has subsequently received considerable research attention [3,4].
Research examining taper has predominantly focused on either identifying the optimal taper strategy or identifying variables underpinning taper's performance-enhancing effects [3,4]. For example, a meta-analysis aiming to find the optimal taper found that a 8-14 day progressive reduction in training volume of 41-60%, which maintains training intensity and frequency, was best for most swimmers, runners and cyclists [3]. Additionally, a host of physiological variables have been studied during taper, including cardiorespiratory, metabolic, biochemical, hormonal, neuromuscular and immunological factors [4]. Of these variables, taper appears to be consistently associated with improvements in blood creatine kinase, testosterone, cortisol, and muscular strength and power, suggesting these physiological variables underpin performance improvements during taper [5][6][7].
Alongside physiological variables, psychological variables have also been proposed as key to understanding taper [4]. Indeed, researchers have examined mood, perception of effort, recovery-stress and sleep quality, with findings from this research typically showing these variables improve following taper [8][9][10]. For example, one study found mood and performance to significantly improve after 14 days of taper with eight cyclists [8]. In another study, 16 triathletes reported significant improvements in total stress and total recovery alongside increased 3-km time trial run performance after a 2-week taper [9]. Finally, a 1-week taper led to significant improvements in the heart rate:perceived exertion ratio and performance of collegiate cyclists [10]. Cumulatively, this research suggests athletes' psychological state improves during taper and may underpin taper's performance-enhancing effects. Developing a better understanding of the psychological changes associated with tapering, including how they relate to known physiological effects, which have received more research attention, is key to ensuring it is optimally implemented and performance maximised.
Despite an understanding of the psychology of taper being important, currently, little knowledge is available detailing what types of psychological research has been conducted, what this research demonstrates and what further research needs to be done. For instance, the last review to be conducted summarising psychological research associated with taper [4] was not systematic, did not analyse the characteristics of psychological research and did not suggest future research areas. Consequently, it is unknown whether all relevant research was identified (and how it was identified), whether there are re-occurring methodological issues associated with psychological research examining taper and where researchers need to focus their attention to further the field. Furthermore, and compounding these three issues, the review is over a decade old and consequently may offer an outdated summary of psychological research examining taper.
Overall, there is a lack of a systematic up-to-date review that summarises psychological research examining taper and identifies future research needs. This represents a significant gap in knowledge as it makes it difficult for researchers to optimally study the psychology of taper, which in turn prevents taper from being effectively implemented. As such, a scoping review was conducted with three aims. First, to determine the characteristics (e.g. designs, participants) of psychological research examining taper. Second, to summarise psychological research examining taper conducted with adult athletes and coaches. Third, to identify gaps in psychological research examining taper and suggest areas of future research.

Methods
We defined a scoping review as a review addressing a broad research question that maps key concepts, types of evidence and gaps in research via systematic searching, selecting and synthesising of knowledge [11]. A scoping review was considered appropriate as its purpose was consistent with our aims of mapping the volume and characteristics of a research area, summarising research relating to a topic and identifying gaps in knowledge [12,13].
The method for this scoping review was informed by the Arksey and O'Malley [13] framework and consisted of five phases: (a) identifying the research question, (b) identifying relevant studies, (c) study selection, (d) charting the data and (e) collating, summarising and reporting the results. For an overview of the review protocol, please see the Electronic Supplementary Material (ESM). The review was conducted in accordance with recent scoping review reporting guidelines (PRISMA-ScR; [14]). All items of the reporting guidelines were met (see ESM), excluding items relating to critical appraisal (items 12 and 16) that are considered optional in scoping reviews [14]. This review was prospectively registered with the Open Science Framework on 17 March, 2021 (https:// osf. io/ xchpg).

Identifying the Research Question
This review was guided by the questions: (a) what types of psychological research examining taper has been conducted in adult sport, with whom and with what measures? (b) what has research examining the psychology of taper found? and (c) where are the gaps in knowledge and how can they be addressed? These questions were developed to clarify the concept (taper), target population (adult sport participants) and outcomes (research findings and future directions) [15], as well as to ensure the limitations associated with the existing understanding of the psychology of taper were addressed.

Identifying Relevant Studies
To identify sources relevant to the research question, articles were identified via five sources: (a) electronic databases (Scopus, 1788-present; Web of Science, 1900-present; Psy-cArticles, 1985-present; PsycInfo, 1806-present; SportDiscus, 1892-present; and PubMed, 1975-present), (b) manual searching of journals (Psychology of Sport and Exercise, Sport, Exercise, and Performance Psychology, Journal of Sport and Exercise Psychology, Journal of Applied Sport Psychology, International Journal of Sport and Exercise Psychology, Journal of Clinical Sport Psychology, Journal of Sport Psychology in Action), (c) reference list inspections, (d) "cited by" searches and (e) from previous knowledge. The six electronic databases were chosen to provide coverage of sport science, psychology and multidisciplinary publications relevant to the research question and identified by the research team in consultation with a university librarian with specialist knowledge of sports science and psychology databases.
Manual searches of journals were first conducted on 29 March, 2021 and then again on 5 November, 2021 using the online search function on journal websites and using the search term "taper". Manual searching involved all aspects of a journal's database (e.g. title, abstract, keyword, full text). A broad and simplistic search term was used to identify the maximum number of relevant articles. Complete search terms, date coverage and search limits used for each electronic and journal database can be found in the ESM.
The reference lists of ten fully screened articles (i.e. those that had passed title, abstract and full-text screening) were manually searched for additional articles [16][17][18][19][20][21][22][23][24][25]. These articles were specifically chosen to ensure an even spread of publication dates across the whole publication period, therefore maximising the likelihood of finding missing articles. "Cited by" searches were also conducted on these ten articles via Google Scholar with the first 100 records being screened for appropriateness in relation to the research questions. Like other scoping reviews [26], limited (i.e. only ten articles searched and only 100 records screened) reference list searches and "cited by" searches were conducted because "cogniti*".ab,id,ti 6 "emoti*".ab,id,ti 7 "behav*".ab,id,ti 8 "sport*".ab,id,ti 9 "pre-perform*".ab,id,ti 10 "recover*".ab,id,ti 11 "fatigu*".ab,id,ti 12 "compet*".ab,id,ti 13 "train*". we felt the comprehensive nature of the database screening meant it was unlikely that further searches would return relevant articles. Additionally, the latest review summarising psychological factors associated with taper was also manually checked for potentially relevant articles [4]. Other potentially relevant articles were identified using the existing knowledge of the research team.

Study Selection
Consistent with recommendations, a two-stage screening process was used in this scoping review to select studies [13]: title and abstract, and full text. During each stage, to be eligible in this scoping review, articles needed to (a) be written in English, (b) be peer-reviewed original articles (including in press articles), (c) examine (quantitatively or qualitatively) psychological factors (i.e. cognitive, emotional, or behavioral factors), (d) be conducted during taper; [1]) or have findings referencing taper, (e) have participants over the age of 18 years and (f) have participants who are athletes (i.e. individuals competing in sport) or sport coaches (i.e. individuals involved in the training of athletes in sport) involved in sport (i.e. competitive physical activity requiring skill and/or physical prowess). Only articles written in English were included as we did not have translation services available. Similarly, only peer-reviewed original articles were included as we were only interested in research that had passed scientific scrutiny. An adult-only sample was chosen as developmental and adult athletes differ physiologically and psychologically [27], and therefore pooling data may confuse understanding. Research that was conducted during taper or referenced taper was used to capture all relevant research related to the studies aims. Psychological research and research that had either an athlete or coaching sample was chosen to ensure only articles relevant to the research questions were identified. No restriction was placed on sport type, study design, methodology (e.g. cross-sectional or longitudinal) or publication date. Identified articles were imported into the web-based systematic review manager Covidence (https:// www. covid ence. org/) for title, abstract and full-text screening. Article titles and abstracts were screened by two reviewers for appropriateness using the eligibility criteria. For articles where there was disagreement, the disagreeing reviewers used the notes function in Covidence explaining their decisions. The reviewers then examined these notes, and a decision was reached whether the article should be included. If no agreement could be made, a third reviewer screened the article, reviewed the notes, and performed a concluding decision. Articles considered relevant after title and abstract screening progressed to a full-text review. Articles that could not be accessed were requested from the original authors. After passing a full-text review, study characteristics were charted.

Charting the Data
Data were charted by the lead author using Microsoft Excel (ESM) and reviewed by the research team. The data chart consisted of relevant study characteristics to be extracted from articles, including author(s), publication date, journal title, study aim, study design, study methodology, number of participants, number of male participants, number of female participants, participant descriptor, sport, taper duration, psychological measure/data collection method, psychological findings, conclusion, strengths and limitations. Full-text screening and data charting were performed by the lead author; however, discussions took place when questions arose about the data charting process.

Collating, Summarising and Reporting the Results
Consistent with scoping review recommendations, we conducted a frequency analysis to identify the characteristics of psychological research examining taper and content analysed article findings to aid with the collation, summarising and reporting of results [13,15]. Specifically, we used a conventional content analysis in which we examined the findings of the identified articles and organised them into re-occurring concepts and ideas [28,29]. A conventional content analysis was chosen because it is recommended when trying to describe a phenomenon, therefore matching the aims of this scoping review [28]. Organisation of re-occurring concepts and ideas was done both deductively, drawing upon previous understanding [9], and inductively, when existing knowledge could not account for the novelty of the data. Where appropriate, athlete and coach data were synthesised to provide a greater understanding. Findings were reviewed by the research team to ensure theme titles and their content were conceptually consistent.

Search and Selection of Articles
The electronic database searches returned 1708 results and additional article searches (excluding citation based searches) returned 51 results. Of these 51 additional articles, 45 were identified via manual journal searches, four via a previous review [23,[30][31][32] and two via existing knowledge and discussions with the research team [22,25]. After deduplication in Covidence, 695 articles were removed, leaving 1064 articles for title and abstract screening. Following title and abstract screening, 972 articles were excluded from the review because of not meeting the eligibility criteria, resulting in 92 articles being left for full-text screening. Most articles were removed at title and abstract screening because of the search query returning unrelated results in disciplines such as engineering and drug efficacy. Full texts for two articles could not be retrieved and were therefore excluded from full-text screening. After full-text screening, 46 articles were excluded resulting in 46 articles being retained for data charting. Two additional articles were identified via "cited by" searches [33,34], resulting in a total of 48 articles being identified and charted (See Fig. 1 for details of the identification and screening progress). quantitative data (n = 38); however, qualitative (n = 7) and mixed method (n = 3) were also collected. Of the quantitative research conducted, most (95%) used a longitudinal design (n = 36), with the remaining studies using a cross-sectional design (n = 2). Longitudinal quantitative research consisted of experimental (n = 20), fieldbased (n = 12) and quasi-experimental (n = 2) research. Of the experimental research conducted, both with (n = 11) and without (n = 9) control group methodologies were reported. Of the qualitative research conducted, most (71%) did not report or make explicit the specific methodological (e.g. grounded theory) or philosophical framework (e.g. interpretivism) used. Two qualitative studies did report their philosophical approach, using interpretive constructionism and pragmatism, respectively.

Characteristics of Psychological Research Examining Taper
Most (92%) articles used an athlete sample (n = 44), with only three articles examining coaches and one article examining both athletes and coaches. In total, the articles included 1588 participants. Of these participants, 1548 were athletes (97%) and 40 were coaches (3%). Of the athletes, 1026 were male (66%) and 475 were female (31%). Of the coaches, 28 were male (70%) and 6 were female (15%). Across four studies [17,[35][36][37], the gender of 47 athletes and six coaches was not reported or made explicit (representing 3% and 15% of the respective total percentages).
To report participant descriptors and sports more coherently, participant descriptors and sports that shared similar semantic meanings were combined (e.g. participants described as "Elite", "Olympic and Paralympic" and "World Class" were categorised together as "Elite" and "Rugby League", "Rugby Sevens" and "Rugby Union" were categorised as "Rugby"). Where participants were given a dual description by the original authors (e.g. regional-national), the lowest descriptor was used. Articles that used athletes from multiple sports were categorised as "multi-sport". Using this classification system, the most (27%) reported participant descriptor was elite (n = 13) [38]. However, overall, most (52%) psychological research used a non-elite sample consisting of university-(n = 12), regional-(n = 7) or national-level (n = 6) athletes. The most reported sport of participants were swimming (n = 11), multi-sport (n = 7) and triathlon (n = 6). One article did not report or make explicit the sport of participants to protect their anonymity [22].

Summary of Psychological Research Examining Taper
In total, eight themes were developed via content analysis [29]: Mood, Perception of Effort, Perceived Fatigue and Wellness, Recovery-Stress, Taper as a Stressor, Stress Tolerance, Psychological Preparation and Cognitive Functioning. Themes are presented in order of the volume of research underpinning them, with larger themes first. See Table 3 for a summary of independent articles' main findings.

Mood
Mood was the most studied psychological construct in the identified articles (n = 20). Most articles (n = 18) measured mood via the Profile of Mood States (POMS) [69], a 65-item questionnaire measuring anger, confusion, depression, fatigue, tension and vigour. Alongside the individual subscales, a total mood disturbance score is also typically calculated. In addition to the Profile of Mood States, two studies used the Brunel Mood Scale [70], a shortened (24-item) version of the Profile of Mood States utilising identical mood dimensions.
Most (85%) research shows mood improves or returns to baseline levels following taper. This effect is consistent across research designs (e.g. experimental or field based), sports (e.g. swimming, triathlon, canoeing, Australian rules, rowing and cycling), and competitive levels (e.g. regional, trained, university, professional, international and elite) [43,44]. Improvements in total mood disturbance following taper is mostly due to increases in vigour and decreases in fatigue [55], likely mirroring improvements in physiological fatigue and recovery (or cognitive appraisals of these).  Sport devaluation, reduced accomplishment, general stress and emotional exhaustion were significantly worse after taper compared with baseline. Selfefficacy significantly worse after taper compared with baseline and overload training A minority of research reported unchanged (5%) or deteriorated (10%) mood following taper [20,24]. Unchanged mood could be related to training load being reduced too much during taper leading to a reduction in fitness [20], overtraining prior to taper leading to significant psychophysiological disruption, which is not reduced during taper [47], or a lack of aerobic exercise leading to increased depression or exercise addiction causing withdrawal [24]. However, an alternative psychological explanation could be that athletes are negatively appraising their performance capabilities during taper, therefore leading to disrupted mood [71].
Mood scales other than vigour and fatigue (i.e. Anger, Confusion and Depression) remain relatively stable throughout taper [25,45]. Exceptions to this is the subscale tension, which can remain elevated following taper [24,45]. For instance, despite total mood disturbance significantly improving following a 28-day taper, tension was found to be significantly elevated above baseline in 22 female collegiate and university swimmers [45]. Elevated tension could be due to anxiety related to the upcoming competition [31]. Another possible explanation is differences in levels of athletic experience influencing symptom appraisal. For example, less experienced athletes may lack the emotional regulation skills needed to positively appraise physiological symptoms [72]. Consequently, less experienced athletes may be more likely to appraise physiological symptoms as tension, rather than a potentially similar psychophysiological symptom such as excitement.
Some research suggests individual differences influence mood responses during taper [31,54]. For example, a crosssectional study found trait anxiety to influence the types and intensity of certain mood responses during taper. Specifically, significant group differences (i.e. high vs low trait anxiety) or group × time interactions were found for anger, depression, tension, confusion and vigour [54]. However, as this study used the State Trait Anxiety Inventory [73], which is a unidimensional measure, it is unknown whether cognitive or somatic anxiety exerts a greater influence on mood responses during taper. Another potentially important individual difference is gender. For example, another cross-sectional study found gender to consistently influence tension scores, with female individuals scoring higher than male individuals during taper [31]. Additionally, gender also influenced vigour and confusion scores across certain swim seasons during taper. Overall, these findings suggest trait anxiety and gender may influence the taper-mood relationship. However, further experimental or longitudinal research is required to confirm the nature and robustness of these findings.

Perception of Effort
Eleven articles measured perception of effort-related constructs during taper. The most used scale was the Rating of Perceived Exertion (RPE; n = 10), or a derivative. The RPE [74] is a subjective evaluation of physical task difficulty [75], usually measured on a 6-20 scale before and after taper.
Other scales used to measure perception of effort-related constructs include the Form Scale [76], Feeling Scale [77], Felt Arousal Scale [78], Action Crisis Scale [79] and short Flow State Scale [80], each of which was used once.
Research suggests perception of effort, as measured via RPE, remains unchanged (62%) or improves (38%) following taper [17,46]. Improvements in RPE following taper have been attributed to physiological recovery and an increased tolerance of higher intensity training [10]. For instance, research has found the RPE-power relationship to significantly improve following taper, suggesting a given power output post-taper resulted in a lower RPE compared with pre-taper [10]. Comparatively, unchanged RPE following taper could be due to low levels of pre-taper fatigue, persistent fatigue during taper or increased motivation due to positive appraisals of recovery, consequently leading to increased effort (and subsequent RPE) during training [10,17,19].
In addition to changes in RPE, other perception of effortrelated constructs can improve during taper [39,41]. For example, significant improvements in perceived form (i.e. the perceived current performance level of the individual), energy and feeling (i.e. how "heavy" or "light" limbs felt) were found with 25 collegiate swimmers after taper [41]. In another study, local runners doing a short-term 2-day taper had significantly less perceived physical strain, negative valence (i.e. negative arousal) and perceived action crises (i.e. conflict between continuation in achieving ones goals and task disengagement) and significantly more flow states compared with participants taking part in a lactate accumulation test [39]. Overall, these findings suggest taper enhances proprioception and facilitates the development of more positive arousal, task engagement and flow states. However, given the limited research in this area, future research needs to confirm the generalisability of these findings. Equally, the study by Venhorst et al. [39] used a relatively untrained sample and an unsupervised short-term (2-day) taper. Consequently, the ecological validity of these findings in relation to trained athletes undergoing a competition taper is questionable.

Perceived Fatigue and Wellness
Nine articles measured perceived fatigue and wellness, using a variety of scales. One commonly used and/or adapted scale is an eight-item questionnaire developed from recommendations by Hooper and Mackinnon [81] measuring perceptions of training, sleep, leg pain, infection, concentration, efficacy, anxiety, irritability and general stress [48,60,61]. With this measure, a cumulative total score of fatigue is also calculated. Other researchers have used three- [57], five- [33] or seven-item questionnaires [16] measuring similar constructs, or measured perceived well-being of the legs [42,63]. To the authors' knowledge, the psychometric properties of perceived fatigue and wellness questionnaires have not been formally examined (e.g. exploratory and confirmatory factor analyses). Consequently, the validity and reliability of these measures is unclear.
Most (78%) articles show perceived fatigue and wellness improve after taper [42,61]. However, two articles (22%) reported unchanged perceived fatigue and wellness scores following taper. Low participant sizes and use of overload training phases may have underpowered the statistical test or overtrained participants, respectively, therefore explaining the unchanged perceived fatigue and wellness scores [16,57].
Research has also found fatigue and wellness to be correlated with physiological variables [48,60]. For instance, changes in the total score of fatigue from intense training to taper were moderately negatively correlated (r = −0.58) [82] with high-frequency heart-rate variability and moderately positively correlated (r = 0.64) with the low-frequency: high-frequency ratio in 13 (male = 9, female = 4) nationalinternational swimmers [48]. In another study, the total score of fatigue was moderately positively correlated (r = 0.61) with the cortisol:cortisone ratio in 16 male elite Rugby Sevens players [60]. These findings suggest improvements in perceived fatigue and wellness during taper are associated with increased parasympathetic influence of the autonomic nervous system and reduced physiological stress.

Recovery-Stress Balance
Eight articles measured recovery-stress using the Recovery-Stress Questionnaire-Sport [83], or its derivatives [84]. Recovery-stress balance is theoretically grounded in a biopsychosocial conceptualisation of athlete fatigue and recovery, therefore distinguishing it from other themes in this review that have measured subjective fatigue (e.g. Perceived Fatigue and Wellness) but are not theoretically based. Most (63%) articles used the original RESTQ-Sport, which is a 76-item, 19-factor questionnaire measuring perceived stress and recovery. The 19 subscales are hierarchically organised into seven general stress subscales (general stress, emotional stress, social stress, conflicts/pressure, fatigue, lack of energy, physical complaints), five general recovery subscales (success, social recovery, physical recovery, general well-being, sleep quality), three sport-specific stress subscales (disturbed breaks, emotional exhaustion, injury) and four sport-specific recovery subscales (being in shape, personal accomplishment, self-efficacy, self-regulation). Researchers have also used shorter 52-item (25%) and eightitem (12%) versions [40,66].
Most (88%) research shows that stress decreases and recovery increases after taper [9,62]. Of this research, 71% used an experimental design, but often without a control group (66%). Consequently, the research lacks ecological validity and the influence of confounding and extraneous variables cannot be excluded. Only one article reported unchanged or increased stress/reduced recovery after taper [40]. This article also found that burnout dimensions of sport devaluation and reduced accomplishment increased after taper, compared with baseline. No explanation for the contradictory nature of these findings compared with other taper studies was offered; however, they could be due to the length of taper reported in the study (i.e. a 10-week period, which is substantially longer than most articles in this review). Consequently, this extensive taper period could have led to detraining [85], which may have negatively impacted perceived stress, recovery and burnout.

Taper as a Stressor
Six qualitative studies have findings suggesting taper may be a stressor for athletes and coaches [18,22,35,51,58,67]. For example, transitioning from taper to fitness training was highlighted as a source of burnout in 15 professional Rugby Union players [35]. Additionally, when interviewing international athletes about competitive and organisational stressors, Hanton et al. [22] found that athletes wanted to have a good start at competition as this told them their taper was "right". These findings suggest athletes consider taper an important performance indicator for their upcoming competition, and that when done poorly, it may be perceived to be a stressor.
Similar findings have been reported by coaches [18,51]. In one study, 12 world class coaches (male = 6, female = 6) reported the preparation phase for major events as a challenge [51]. Specifically, one coach noted that "making sure the taper is right" (p. 453) was a stressor when preparing athletes for competition. Additionally, coaches also noted that managing athletes psychologically becomes more challenging closer to competition, as they do not behave or think in the same way they normally do [51]. Extending this, another study identified specific challenges coaches face during taper, including being negatively affected by the environment and having to maintain their composure and emotions around athletes [18]. Taken together, these findings suggest coaches face personal and interpersonal challenges specific to taper.
There is some evidence that coach and athlete behaviours change during taper, potentially owing to the stressors they experience [58,67]. For example, seven elite athletes reported using self-compassion during taper as a coping mechanism to manage self-criticisms, prevent rumination and enhance self-belief [67]. These findings suggest athletes can be susceptible to having negative performance-related thoughts and that coping mechanisms, such as self-compassion, may be beneficial in managing these. In another study looking at the dark side of leadership behaviours in sport (i.e., Machiavellianism, psychopathy and narcissism), 15 elite male managers, head coaches and/or performance directors reported stopping using dark side behaviours during taper [58]. Although no explanation for this was provided, it could be to not "rock the boat" close to competition, possibly to reduce uncertainty and stress experienced by athletes and coaches. Like the previous theme (Psychological Preparation), further taper-specific research is required to understand the sources and impact of stress during taper.

Stress Tolerance
Four articles were identified measuring stress tolerance during taper. Stress tolerance was measured using The Daily Analysis of Life Demands for Athletes (DALDA). The DALDA is a 34-item questionnaire consisting of two parts: sources of stress (e.g. training and exercise) and symptoms of stress (e.g. unexplained aches) [86] in relation to training. Like perceived fatigue and wellness questionnaires, the psychometric properties of the DALDA have never been examined and therefore its validity and reliability are unclear.
Most (75%) research shows that sources of stress remain unchanged while symptoms of stress decrease [36,49]. For example, symptoms of stress were significantly reduced in 16 male national-international triathletes following a 4-week progressive overload and a 2-week taper. Furthermore, performance on a 3-km running time trial had a weak positive correlation (r = 0.30) [82] with "worse than normal" responses to symptoms of stress [49]. Overall, these findings suggest that during taper, athletes experience the same stressors but at a weaker intensity, or that they are more effectively coping with the symptoms. However, most (75%) of this research used an experimental design, thus further research needs to be conducted in applied settings to confirm these findings.
Researchers have also examined the relationship between stress tolerance and physiological variables during taper, finding mixed results [36,65]. For example, a weak negative correlation (r = −0.20) [82] was found between parasympathetic (lnRMSSD) heartrate variability and stress tolerance during taper with 16 soccer players [65]. However, a moderate positive correlation (r = 0.41) was found between day-to-day fluctuations in parasympathetic heart-rate variability activity (lnRMSSD cv ). Additionally, a different study found a strong positive correlation (r = 0.71) between symptoms of stress and cortisol and a moderate negative correlation (r = −0.68) between symptoms of stress and the testosterone-cortisol ratio in ten nationally ranked tennis players [36]. However, this relationship was found for the whole study duration (6 weeks of pre-season that included 1 week of taper), rather than for taper specifically. Mixed findings could be due to poor reliability or validity of the DALDA, certain physiological variables being more closely related to changes in DALDA scores than others (e.g. hypothalamic pituitary axis activation vs sympathetic-parasympathetic nervous system) or intersport differences in training load.

Psychological Preparation
Two qualitative [18,37] and mixed-method studies [64,68] have findings suggesting taper helps prepare athletes psychologically for competition. For example, one qualitative study reported that an elite athlete recognised they were in the optimal psychological state (defined as automatic and successful skill execution and performance feeling effortless) during taper [37]. However, what this optimal psychological state looks like during taper for different individuals and across contexts (e.g. different sports) is unknown and likely to be key to ensuring performance is maximised. Similarly, in a different qualitative study with seven Olympic and Paralympic track and field coaches, instilling confidence, coach honesty, appropriate praise, being there for the athlete and mutual confidence were identified as important factors in ensuring athletes were psychologically prepared during taper [18]. Overall, these findings suggest taper is a period in which athletes become psychologically ready to compete. However, as this research used retrospective interviews that may be susceptible to recall bias, further research is required to confirm their importance and performance impact.
Two mixed-method studies support the argument that taper is important for psychological preparation. For example, using a survey design, 72 (male = 33, female = 39) CrossFit athletes were asked (among other questions) why they taper, with athletes highlighting psychological readiness and recovery as key factors [68]. Meanwhile, a survey of 454 regional-professional strongman athletes [64] again identified psychological readiness as an important reason for engaging in taper. Taken together, these findings suggest athletes taper to be psychologically ready for competition. However, given the sport specificity and retrospective selfreport nature of both surveys, whether the findings are valid across sport contexts is unknown.

Cognitive Functioning
One article [53] measured cognitive functioning via a computerised Stroop word colour test [87]. During a Stroop word colour test, participants must quickly and correctly identify the colour of unrelated words (i.e. the written words were not related to the colour of the ink the words were written in). Cognitive functioning was found to improve in 11 male provincial endurance athletes following a 2-week training overload and a 1-week taper [53]. Although these findings suggest taper improves cognitive functioning, the experimental nature of the study combined with the small sample size and relatively low competitive level of participants means the research has poor ecological validity.

Discussion
This scoping review had three aims. First, to determine the characteristics of psychological research examining taper. Second, to summarise psychological research examining taper conducted with athletes and coaches. Third, to identify gaps in psychological research examining taper and suggest areas of future research. The following sections summarise the characteristics and findings of psychological research examining taper and identify gaps and future areas of research.
Most identified articles were published in the last 15 years across sports medicine, sports science, strength and conditioning, and applied sport psychology journals. Most articles identified were quantitative, using a longitudinal experimental or field study design and male athletes competing at a university, national or regional level. Of the articles identified, the most studied sport was swimming and the most common taper durations were 7 (n = 10), 14 (n = 8) or 21 days (n = 6). Eight themes were developed to summarise psychological research examining taper: Mood, Perception of Effort, Perceived Fatigue and Wellness, Recovery-Stress Balance, Taper as a Stressor, Stress Tolerance, Psychological Preparation and Cognitive Functioning. Research across these themes suggests taper is associated with improvements in mood, perception of effort, perceived fatigue and wellness, recovery-stress, symptoms of stress and cognitive functioning [9,46,49,53,61]. However, findings also suggest contextual and individual differences are important in influencing psychological outcomes during taper. For example, gender and trait anxiety may influence mood responses, tension can remain elevated during taper (possibly indicative of performance anxiety) and changes in the perception of effort may vary across sports [10,45,54]. Furthermore, qualitative and survey-based research offers novels insight into the psychology of taper, by suggesting it may be a unique stressor for athletes and coaches and that it is used as a specific psychological preparation tool [18,22,51,68]. Cumulatively, this review suggests taper has multi-faceted psychological effects on athletes and coaches that are influenced by contextual and individual variables. However, despite this review highlighting the breadth and depth of psychological research examining taper, there are several limitations associated with the current evidence base and, as a consequence, many questions remain unexamined.
Results from the current study suggest, despite being studied for 30 years, the psychology of taper is underresearched. Indeed, few psychological constructs have been examined and most psychological research has been published in either sports medicine or strength and conditioning journals. This suggests that developing psychological knowledge has often not been the main aim of researchers. This is supported by researchers choice of measures, which are generally consistent with that of training monitoring rather than psychology [88]. The overall consequence of this is a superficial understanding of athletes and coaches psychological functioning during taper that prevents coaches and practitioners from integrating psychological knowledge into the planning and implementation of taper. Because of this, exploratory research is needed that explicitly examines the psychology of taper and critically discusses these findings in relation to existing psychological theory and empirical research.
There are two key areas where researchers could conduct exploratory research examining the psychology of taper. First, they could develop an inductive understanding of the psychology of taper by using semi-structured interviews to explore athletes' and coaches' psychological experience. Such research could be key in identifying salient psychological variables associated with taper, which could then act as a catalyst for further research. Second, they could build upon existing novel findings synthesised by this review. For example, researchers could examine confidence, the coachathlete relationship, stress, and the multi-dimensional nature of state and trait anxiety, as these are novel constructs in taper research, but have been studied extensively in sport psychology [89]. For example, researchers could identify sources of confidence or stress during taper in athletes and coaches using semi-structured interviews or focus groups. Additionally, researchers could longitudinally examine how confidence, anxiety and performance fluctuate before and during taper leading into a real competition.
Most psychological research identified by this scoping review examines basic questions, such as whether variables change from pre-to post-taper. Although this research is useful in showing how taper influences these variables, this type of research is reductionistic in reducing the potentially complex psychological experience of taper. Indeed, many psychological questions remain unanswered, such as how psychological variables fluctuate during taper, how psychological variables interact and influence one another during taper, and how pre-taper psychological states influence during taper psychological states. Because of these limitations, researchers could build upon existing research by asking more advanced research questions. For example, researchers could study what mediates or moderates the relationship between psychological variables, such as mood or recovery-fatigue balance, and post-taper performance. Specifically, researchers could examine whether social (e.g. coach-athlete relationship, group cohesion, teamwork) or individual differences (e.g. personality) interact with the relationship between taper and mood (or other alreadymeasured variables) or post-taper performance. Examining the interaction or association between physiological and psychological variables during taper (i.e. conducting multidisciplinary research) may also be fruitful avenues for research. For example, interpretations of physiological states are an antecedent of self-efficacy [71], which directly influences athletic performance [90]. In turn, successful athletic performance further enhances self-efficacy, therefore causing a positive feedback loop [71]. Consequently, it is likely interpretations of physiological changes during taper have psychological and performance implications. To examine this, future researchers could seek to develop a theoretically informed model of the relationship between fatigue/ recovery, strength, power, self-efficacy, and performance and then examine this with athletes during taper. Similarly, little is known about how perceived fatigue monitoring can be used to make real-time refinements to taper, and what impact this has on performance and athletes' optimal psychological states. Research could therefore develop and test a protocol that uses perceived fatigue to alter training load and examine the impact this has on psychological variables (e.g. confidence) and performance.
Psychological research identified by this scoping review has focused predominantly on male athletes, with one study undertaken with coaches [18] and none with disabled athletes. This represents a significant gap in knowledge, as gender has been shown to influence psychological variables during taper [54], coaches may be susceptible to stress during taper [51], and tapering effectively is important in disability sports as athletes may be susceptible to overtraining or training inconsistently [91]. Consequently, there is a clear need for the inclusion of more diverse populations within this research area. Researchers could therefore quantitatively examine whether gender moderates how athletes psychologically respond to taper. Equally, researchers could qualitatively explore coaches understanding of taper. Finally, researchers could conduct exploratory research examining taper in disability sports, by studying what taper means physiologically and psychologically to disabled athletes and how it is implemented by coaches.
No intervention research was identified by this review, and therefore the effectiveness and efficacy of strategies for enhancing performance and psychological outcomes with adult athletes during taper remain unknown. The lack of intervention research is likely owing to a lack of understanding around what psychological variables are important during taper, and therefore psychological research needs to work towards building an evidence base that can be used to implement interventions to improve psychological states and/or sport performance during taper. Consequently, future research should begin examining the impact of psychological interventions during taper, potentially using findings from the aforementioned future research directions as a theoretetical foundation. Specifically, using a single case design, researchers could explore the impact of selfefficacy or biofeedback-based interventions on athletes' performance and psychological state prior to, or during, taper. Equally, researchers could implement interventions targeting psychological variables moderating or mediating the relationship between taper and performance at the team or organisational level (e.g. coach-athlete communication, motivational climate).

Limitations
This scoping review has several limitations. For example, we only included articles that used an adult sample, meaning we may have excluded insightful research using an under 18 years of age sample. However, we only wanted to review adult research to provide a specific understanding of the current research base given the developmental differences between adults and adolescents [27]. Another limitation was the elements of our search protocol. For example, we only searched at the title, abstract, keyword and subject heading (where allowed) level. This was done to ensure searching was consistent across the different databases; however, using a different protocol (e.g. searching using all database tags) may have returned different results. Despite this, our use of subject heading-based searches, alongside alternative searching strategies (i.e. reference lists, "cited by" searches and manual journal searches), would have likely mitigated against this. A final limitation of this review is its lack of systematic quality appraisal, therefore meaning the quality of the reviewed research is unknown. The lack of a systematic quality appraisal is consistent with scoping review recommendations and aims, whereby the aim is not to determine the quality of evidence but rather to map the research area [13]. However, where appropriate we have evaluated evidence to provide readers with a critical understanding of research findings.

Conclusions
This study represents the first rigorous and transparent review of psychological research examining taper and significantly contributes to the literature in three ways. First, this is the first review to highlight the key characteristics of psychological research examining taper, therefore offering novel insight into the types of research being conducted and who it is being conducted with. Second, this review builds upon and extends existing understanding of psychological research examining taper [4] by providing an up-to-date and critical summary of current and emerging psychological research examining taper. Third, this is the first review to consider the literature as a whole and offer future research directions to advance the field. Overall, this scoping review has highlighted the lack of research examining the psychology of taper and the need for focused research that asks more complex questions across diverse populations.

Supplementary Information
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