3.2. Study Quality Ratings
Table 2 includes our individual study bias concerns across the following five categories: subject selection, sample background, participant anonymity, data collection procedures, and questionnaire or qualitative theme reporting. We noted some concern in just over half of the studies regarding subject selection. Given MMA research is not the level of clinical based research with random selection and the like, the subject selection procedures overall seemed adequate, especially with the number of professional including UFC athletes as participants. Hence, for our second bias category concerned with the sample’s MMA background, the vast majority (n = 13) we rated from no (n = 4) [
23,
29,
34,
35] to low (n = 3) [
22,
24,
30] to some (n = 6) [
25,
27,
28,
31,
32,
33] concern. Though it is not a requirement to state participant anonymity assured, it seems relevant. Most likely, researchers assured anonymity within their human subject participant forms. However, only three studies [
23,
29,
35] specially wrote anonymity assured in their method section. Concerning data collection, most studies (n = 12) collected their data directly from their participants. Only, Chen and Cheesman [
25] collected data via an online survey. Concerning our last bias category, questionnaire or qualitative theme reporting, we found no need for concern with the qualitative studies [
30,
31,
32,
33,
34,
35,
36]. We found concern with the quantitative studies, as more than half failed [
22,
26,
27,
28] to report study level reliability. Overall, we found the quantitative studies of greater risk for bias than the qualitative studies.
3.3. Quantitative Studies
Table 3 (topic, main analyses, and study design) and
Table 4 (result summary and meaningfulness) contain specifics for all studies [
22,
23,
24,
25,
26,
27,
28,
29,
30] with quantitative data. Mood was the only repeated topic [
24,
28], but not with the same objective. Both studies appeared to utilize the Portuguese version [
37] of the Brunel Mood Scale [
38]. The topics were stress and coping [
22], social facilitation [
23], weight loss and mood [
24], mood difference based on competition schedule [
28], mental toughness [
25], talent development requirements [
27], and motivations for starting MMA [
26]. Perceptions of aggression (and relation to competitive success) based on facial features was the other topic, with non-competitive MMA fighters as the raters [
29]. Last, in the mixed-methods study, Cunningham and Turner [
30] reported on self-referenced beliefs and acceptance data of MMA athletes. All studies except one [
29] presented mean level data, and two [
23,
25] presented both mean level and correlational. Many studies [
22,
25,
26,
27,
28,
29] were cross-sectional, though a few [
24,
30] spanned at least a month. The Blomqvist Mickelsson and Shaw’s [
23] study utilized archival data over a three-year period.
Concerning result interpretation (see
Table 4), we sought to report effect size values, author reported or calculated or interpreted (e.g., reported correlations) by us. Specifically, MMA fighters whose income depends on fighting reported greater stress than those whose income does not solely depend on fighting [
22]. In addition, in Belem, regardless of income needs, MMA fighters who had a diverse set of coping strategies had better physical and psychological recovery during competitions. Though insufficient data existed to calculate precise effect sizes for these result as the authors reported Spearman rank correlations or limited mean difference statistics, examination of the presented data suggest small effects in all Belem’s summarized results.
In the first of the two mood studies [
24,
28], competitive MMA fighters who used rapid weight loss strategies produced greater results (i.e., more weight loss) than those without a strategy with this weight loss accompanied by increased confusion and total mood disturbance [
24]. We interpreted the mood changes as small with author reported effect size values for the significant findings. Continuing with the theme of mood, Silva [
28] found that tension and anger increases when the MMA athletes have a scheduled fight. We calculated mean difference effect sizes for tension and anger, as well as fatigue and confusion. Averaged together, the effect size was medium, with the upper end of the 95% confidence intervals being large. Hence, we believe Silva and colleague’s [
28] data might be more important than reported.
Three studies [
25,
26,
27] examined often-researched psychological constructs, namely mental toughness, talent and excellence characteristics, and motivation. Regarding mental toughness, Chen and Cheesman [
25] reported data on superior athletic performance and enhanced mental toughness. Chen and Cheeseman viewed their results supporting the research literature suggesting superior athletic performance and performers possess greater mental toughness than their less superior competitors do. Based on the effect size data presented by the authors [
25], the differences were medium between MMA professionals and non-professionals on three mental toughness components (i.e., determination, positive cognition, and confidence). In the same line of reasoning as Chen and Cheesman [
25], Ruiz-Barquin and colleagues [
27] examined psychological characteristics required to develop excellence. They concluded superior psychological abilities for developing excellence as characteristics of MMA competitors compared to athletes of other sports, those being long-term support, use of imagery, and quality practice. We calculated effect size values between the MMA sample and the other archival sport data sets. The effect sizes were medium, with the 95% confidence interval ranging from medium to large. Kuśnierz et al. [
26] examined a variety of motivation factors for beginning MMA training. They reported the most prominent being enjoyment from training entertainment. Other motivating factors included the benefit of the sport for improvement of health and enjoyment of learning new fighting techniques. We found insufficient data reported for effect size calculations. In addition to specifics to MMA enjoyment, the authors [
26] reported MMA athletes (and the boxing participants) self-reported greater internal compared to external motivations for their sports.
Blomqvist Mickelsson and Shaw [
23] and Třebický et al. [
29] uniquely studied MMA and sport psychology topics by way of archival MMA data. Blomqvist Mickelsson and Shaw [
23] interpreted their findings that the presence of an audience impaired MMA fighters’ performances. Though we found insufficient data to calculate effect size values, our visual inspection of their frequency graph suggested to us a large effect. It appears audiences do indeed impair MMA fighter performances when compared to the COVID-19 pandemic audience, less fights. Třebický et al. [
29] likewise used existing MMA competitor data (faces and fight records). After having facial features rated by a large sample of on-MMA participants, the authors reported perceptions of aggression might relate to success. The reported correlation was small; thus, the success of MMA fighters used in the study related to success, albeit small in magnitude.
Last for the quantitative data reported, Cunningham and Turner [
30] reported participants 2 and 3 (participant 1 did not complete the study) in their mixed-methods study had post and 6-month post treatment reductions in total rational beliefs and self-depreciating thoughts. The differences ranged from small to medium in meaningfulness.
3.4. Qualitative Studies
Table 5 contains specifics (topic, main analysis, and study duration) for studies [
13,
30,
31,
32,
33,
34,
35,
36] with qualitative data. Based on the author stated objective and our reading of the individual articles, the topics were traditional sport psychology topics [
13,
32,
33,
36], aggression/violence [
34,
35], REBT therapy [
30], and the fighting experience [
31]. The researcher methodologies varied a bit. They described the following as the approaches: phenomenological [
13,
31,
35], grounded theory [
32,
34], reversal theory [
34], ethnography [
36], and note reflections [
30]. Half of the studies interviewed the participants once [
13,
31,
34,
35] while the other saw and interacted with the participants from at least 6 months [
30], to a year [
32,
33] and finally for two years [
36].
As with our quantitative studies, we sought to interpret the author stated results with more details, specifically with our finding and reporting their higher-order themes.
Table 6 contains the specifics. Harpold [
13] sought to ask his amateur MMA athletes about their mental skills use. Five themes emerged concerned with confidence, arousal regulation, imagery, mental toughness, and motivation. Massey and colleagues [
32,
33] with extensive notes, observations, and interviews over one year with nine MMA athletes including some who competed in the UFC examined psychological training and competition factors and self-regulation strategies to enhance performance. Massey et al. [
32] reported five higher-order themes concerned self-regulation as a process of motivation, both internal and external, and ongoing evaluation. The researchers [
32] also reported MMA athletes deliberately induce pain and mental distress as part of their psychological training. Massey and colleagues [
33] with the same participants reported behavioral processes, embodied emotions, and psychological strategies are invaluable for enhanced performance. Our summary of Massey et al. [
33] included higher-order themes such as self-liberation, counter conditioning, stimulus control, contingency management, and helping relationships. Last, of the psychological skills focused qualitative studies, Vaccaro et al. [
36] over two years with 215 competitive MMA athletes, examined fear management. Their [
36] summary was fighters feared injury and losing, with the fear of both needing management. More experienced fighters were capable of concealing and controlling their fear, as newer competitors tended to struggle because of the lack of strategies/experience [
36]. The four higher-order themes centered on personal fear to using the fear as a performance strategy (i.e., fostering fear).
For the two studies examining aggression/violence, Rosario et al. [
34] interviewed professional MMA fighters. Given the violent nature of combat sports, the MMA fighters viewed aggression as an important mood state for success when used as a strategy. We pulled five themes from Rosario and colleagues’ work concerned with aggression defined, importance, influential factors, use in training versus competition, and some reversal theory concepts. Serrano Rodrigues and colleagues [
35] examined the psychology of violence in fighting. As with Rosario et al. [
34], we reported five overall themes from Serrano Rodrigues et al. Those themes included knowing when to use violence/aggression in matches as opposed to using violence/aggression without focus and disproportionately. Unquestionably, and again logical to combat sports, violence/aggression is required for success. The interviewed MMA fighters reported the need to master the use of violence/aggression for success.
First of the two unconnected studies, Jensen et al. [
31], interviewed MMA competitors, amateur and professionals, concerning the most important factors within their fighting experience. Jensen et al. reported the chaotic nature was the most important experience. The higher-order themes were the cage reality, fighting skill, purpose, and community. The community theme we took at the sport psychology nature of Jensen and colleagues’ work. The qualitative aspect of Cunningham and Turner’s [
30] mixed-methods study reported participants’ ability to change self-depreciation and acceptance thoughts. The previously discussed quantitative data seemed of more value to understanding the value of REBT. Certainly, the study notes are also of value. For instance, participants reflected on other MMA athletes, seeing how anxiety was a limiting fault and the need to decrease such negative thoughts. In addition, the participants changed their perception of enhanced athletic performances by gaining self-confidence in themselves by respecting their strengths and their opponent’s weaknesses.