key: cord-0802284-fafzx8jq authors: Millet, Grégoire P.; Brocherie, Franck; Burtscher, Johannes title: Olympic Sports Science—Bibliometric Analysis of All Summer and Winter Olympic Sports Research date: 2021-10-20 journal: Front Sports Act Living DOI: 10.3389/fspor.2021.772140 sha: dcb5d70415aa73b82754db2eca17811694a573c0 doc_id: 802284 cord_uid: fafzx8jq Introduction: The body of scientific literature on sports and exercise continues to expand. The summer and winter Olympic games will be held over a 7-month period in 2021–2022. Objectives: We took this rare opportunity to quantify and analyze the main bibliometric parameters (i.e., the number of articles and citations) across all Olympic sports to weigh and compare their importance and to assess the structure of the “sport sciences” field. The present review aims to perform a bibliometric analysis of Olympic sports research. We quantified the following topics: (1) the most investigated sports; (2) the main journals in which the studies are published; (3) the main factors explaining sport-specific scientific attractiveness; (4) the influence of being in the Olympic programme, economic weight, and local influences on research output; and (5) which research topic is the most investigated across sports. Methods: We searched 116 sport/exercise journals on PubMed for the 40 summer and 10 winter Olympic sports. A total of 34,038 articles were filtered for a final selection of 25,003 articles (23,334 articles on summer sports and 1,669 on winter sports) and a total of 599,820 citations. Results and Discussion: Nine sports [football (soccer), cycling, athletics, swimming, distance & marathon running, basketball, baseball, tennis, and rowing] were involved in 69% of the articles and 75% of the citations. Football was the most cited sport, with 19.7 and 26.3% of the total number of articles and citations, respectively. All sports yielded some scientific output, but 11 sports (biathlon, mountain biking, archery, diving, trampoline, skateboarding, skeleton, modern pentathlon, luge, bobsleigh, and curling) accumulated a total of fewer than 50 publications. While ice hockey is the most prominently represented winter sport in the scientific literature, winter sports overall have produced minor scientific output. Further analyses show a large scientific literature on team sports, particularly American professional sports (i.e., baseball, basketball, and ice hockey) and the importance of inclusion in the Olympic programme to increasing scientific interest in “recent” sports (i.e., triathlon and rugby sevens). We also found local/cultural influence on the occurrence of a sport in a particular “sport sciences” journal. Finally, the relative distribution of six main research topics (i.e., physiology, performance, training and testing, injuries and medicine, biomechanics, and psychology) was large across sports and reflected the specific performance factors of each sport. The Olympic sports (https://olympics.com/en/sports/) bring together a large and diverse range of human abilities that extend far beyond the Olympic motto, "Citius-Altius-Fortius" (i.e., Faster-Higher-Stronger"), and outstanding genetic, physical, technical and mental skills are required to reach an Olympic podium. It is therefore not surprising that behind each athlete is an interdisciplinary team of experts/scientists (Hodson, 2021) . Elite sports performance has long been a fascinating field of research for scientists. The 1922 Nobel Prize in Physiology or Medicine, awarded to Sir A. V. Hill and his work on the best middle-distance runners of his time, provides a perfect example of ground-breaking research originating from related questions (Hill, 1925) . Over the last two decades, the "sport sciences" field has massively expanded, as evidenced by the continuously growing number of journals (e.g., 85 journals in 2021 vs. 58 in 1998 in the "sport sciences" category of the Incites journal citations report-https://jcr.clarivate.com). The original definition of sport sciences as "the study and application of scientific principles and techniques to improve sporting performance" (Lippi et al., 2008) has become too narrow, and researchers in different scientific fields (e.g., antidoping sciences, biomechanics, physiology, nutrition, injury prevention and rehabilitation, psychology, pedagogy, management and marketing, history, sociology and many biomedical fields, including preventive medicine and oncology) (Millet and Giulianotti, 2019) are producing an enormous body of research related to exercise and sports. However, to our knowledge, there has been no comprehensive analysis of the "sport sciences" field and no comparison of the sport-specific scientific literature across all Olympic sports. Currently available bibliometric analyses are limited to the most cited articles in sport and exercise medicine (Knudson, 2011; Khatra et al., 2021) or specifically concern a single sport, such as football (soccer) (Brito et al., 2018) , or a specific scientific field (e.g., sports economics, sports management or sociology) (Santos and Garcia, 2011; Shilbury, 2011; Gau, 2013) . In 1992, the summer (Barcelona) and winter (Albertville) Olympic games took place for the last time in the same year. Due to the COVID-19 pandemic, the two games (Tokyo 2020 Summer Olympic Games between 23 July and 8 August 2021 and Beijing 2022 Winter Olympics between 4 and 20 February 2022) will now be organized within a 7-month timeframe. This may be an occasion to review the science across all summer and winter Olympic sports. The present review aims to perform a bibliometric analysis of Olympic sports research. We quantified the following topics: (1) the most investigated sports; (2) the main journals in which the studies are published; (3) the main factors explaining sport-specific scientific attractiveness; (4) the influence of being in the Olympic programme, economic weight, and local influences on research output; and (5) which research topic is the most investigated across sports. The data were obtained by a search in PubMed followed by a search conducted in Web of Science (Clarivate Analytics, USA). First, we selected 116 "sport sciences" journals (Table 1) , including 85 journals of the "sport sciences" category in the Incites journal citations report (Clarivate Analytics, USA); then, we expanded the search to other journals with "exercise" or "sport" in the title. Second, we chose to limit the analysis to sports that are currently in the Olympic programme for Tokyo 2020 (Table 2A) and Beijing 2022 (Table 2B ). This list of sports does not contain sports to be included in the Paris 2024 Olympic Games or sports eliminated from the Olympic programme. We split some sports into subdisciplines (e.g., athletics and distance running and marathon or walking; Alpine skiing and Nordic skiing; cycling and mountain biking) when their natures were too different and sufficient data were available. The search was performed on 4-5 June 2021 on article titles, and the inclusion and exclusion items are displayed in Table 3 . Searching for only the sports or athletes (e.g., judo and judoka) in all these "sport sciences" journals would have yielded 103,164 articles, with many of them irrelevant in terms of our goals. By selecting only articles related to the selected sports-e.g., excluding animal, paralympic, and ultra-sports and fulfilling the inclusion and exclusion (e.g., "American football" for "football" or "water skiing" for "alpine skiing" or "athletes") criteria (see Tables 3A,B for the specific criteria of each sport), we reduced the final number of articles to 25,003 (23,334 articles on summer sports and 1,669 on winter sports). If two different sports were mentioned in the article title, the article was allocated to both. All articles were double-checked (GPM and FB) for conformity with the selection criteria. Auto citations were not removed from this analysis. On 15 June, we performed a complete search for all these articles on Web of Science (Clarivate Analytics, USA). Basic information, including author(s), source journal, publication year, citations per year, and the total number of citations as well as keywords, was extracted. For each sport, the articles were listed based on citation frequency from highest to lowest, and the main metrics were averaged for the top 10 articles in each sport. We compared the dates of the Olympic debut and the first publication for each sport (Figure 1 ) and for the "recent" Olympic sports (i.e., with an Olympic debut in 1998 or later) to display the potential influence of being in the Olympic programme on the scientific interest in a sport (Figure 2) . We also compiled the keywords related to six main research topics [1. Physiology; 2. Performance; 3. Training and testing (i.e., fitness, testing, training); 4. Injuries and medicine (i.e., "Marathon" and "Walking" (Athletics) as well as "Mountain biking" (Cycling) are displayed separately. Skiing is displayed in 2 separated categories: "Alpine and freestyle skiing" and "Nordic skiing." doping, injuries, medicine, rehabilitation); 5. Biomechanics (i.e., biomechanics, movement, motor control, equipment); 6. Psychology] for each sport. We display the top 5 most cited articles for every summer (Table 4 ) and winter (Table 5) Olympic sport. The bibliometric analysis was performed on 50 Olympic sports or disciplines in 116 "sport sciences" journals and led to the selection of 25,003 articles with a total number of ∼600,000 citations. There is a large range of articles and citations across sports (Figure 3) . Nine sports (football, cycling, athletics, swimming, distance & marathon running, basketball, baseball, tennis, and rowing) were involved in 69% of the articles and 75% of the citations. Football (soccer) was the most cited sport, with 19.7 and 26.3% of the total numbers of articles and citations, respectively. Scientific research has been published on all sports, but 11 sports (biathlon, mountain biking, archery, diving, trampoline, skateboarding, skeleton, modern pentathlon, luge, bobsleigh, and curling) accumulated a total of fewer than 50 publications. While ice hockey is the most prominently represented winter sport in the scientific literature, winter sports overall have produced minor scientific output. The analysis of the level and depth of the 10 most cited articles in every sports confirms this discrepancy across sports (Figure 4 ). This analysis confirms the results in terms of total publications across sports (Figure 3 ). Some sports (e.g., basketball and baseball) have highly cited articles (i.e., based on the average number of citations of the 10 most cited articles). This is also the case for handball, which has a relatively low number of citations (Figure 3 ) but a few highly cited articles (Figure 4) . Next, we analyzed the distribution of "Olympic sport sciences" publications across journals. This investigation revealed that only a small number of journals have published the greatest part of such articles. Merely six journals (J Strength Cond Res, 10.0%; J Sports Sci, 7.7%; J Sports Med Phys Fitness, 6.2%; Br J Sports Med, 5.5%; Int J Sports Med, 5.3%; and Med Sci Sports Exerc, 5.2%) of the 116 included in our search had published 40% of all publications ( Figure 5 ). Some factors (including the nature of the sport as well as geographical and cultural factors and the composition of the editorial board), however, seem to have influenced the ratio of articles on specific sports appearing in different journals. For example, baseball articles have been published mainly in orthopedic or "sports medicine" journals (1. Am J Sports Med; 2. J Shoulder Elbow Surgery, and 3. Orthop J Sports Med) while basketball articles were published in conditioning or "sport sciences" journals (1. J Strength Cond Res; 2. J Sports Sci, and 3. J Sports Med Phys Fitness). Tennis articles are overrepresented in Br J Sports Med, and Nordic skiing articles in Scand J Med Sci Sports. Finally, the distribution of different research topics (i.e., physiology, performance, training and testing, injuries and medicine, biomechanics, and psychology) varies largely among sports (Figure 6 ). The present bibliometric analysis is the first to quantify the bibliometric across all summer and winter Olympic sports. This comprehensive review provides interesting outcomes that are summarized briefly here and discussed afterwards: The number of articles found with the inclusion criteria and with the subsequent exclusion criteria and "manual cleaning" of the database are displayed. 1. There is a large difference in scientific output among sports, with nine sports representing 75% of the citations and 11 having a total of fewer than 50 associated publications. 2. Football (soccer) is by far the leading Olympic sport in terms of bibliometrics. 3. Team sports, particularly American professional sports (i.e., baseball, basketball, ice hockey), generate high scientific interest. 4. Overall, winter sports generate minor scientific output. 5. Most articles have been published in a limited number of journals. 6. Whether the inclusion of a sport in the Olympic programme translates into an increase in scientific publications remains unclear. 7. We also report some influence of local/cultural factors and/or of editorial board composition on the importance of a given sport in a given journal. 8. Finally, the distribution of articles among six main research topics (i.e., physiology, performance, training and testing, injuries and medicine, biomechanics, and psychology) highlights the (scientific) performance determinants of each sport. To our knowledge, there has been no comprehensive analysis and comparison of the largely different physical demands across all Olympic sports since the multifactorial determinants of performance within and across all Olympic sports render such analysis difficult. For example, curling and shooting have little in common with boxing, triathlon, or freestyle skiing. A quantitative comparison of the "sport sciences" literature across all these sports, on the other hand, is feasible and provides information on the scientific importance of the various sports. Our analysis revealed that only nine sports (football, cycling, athletics, swimming, distance & marathon running, basketball, baseball, tennis, and rowing) represented 69% of the articles and 75% of the citations, while 11 sports (biathlon, mountain biking, archery, diving, trampoline, skateboarding, skeleton, modern pentathlon, luge, bobsleigh, and curling) accumulated a total of fewer than 50 publications. Why a given sport attracts many publications certainly depends on a number of variables. Unsurprisingly, the sports with the most published and cited articles are very popular, and most of them are long established in the Olympic programme, e.g., from the start in 1896-1900, with the exceptions of basketball (1936) and baseball (1992) . While the time since inclusion in the Olympic programme seems to be a key criterion for the attraction of scientific interest for some sports, this appears not to be the case for other, even "traditional" Olympic sports, such as wrestling or fencing (both Olympic sports since 1896). Another criterion for scientific attractiveness may be individual vs. team sports. Team sports are highly investigated, as is confirmed by our finding that five team sports (football, basketball, volleyball, handball, and ice hockey) rank among the top 12 most cited of the 50 sports analyzed. Conversely, the impact on the scientific literature is lower in other team sports, including field hockey, water polo and rugby sevens (a recent inclusion in the Olympic programme). When analyzing the individual sports, it is noteworthy that the sports in which performance is determined mainly by energy (aerobic and anaerobic) production-as conceptually opposed to "motor control" or "technical" sports categorieshave led to a larger scientific output. Sports belonging to the first category include cycling, athletics, swimming, distance running-marathon and rowing, all of which rank among the top 10 most cited sports. Baseball (see below) and tennis are the exceptions, representing technical sports in this top 10 ranking. Supporting this notion, the technical sports golf (despite its media prominence) and gymnastics (one of the most important Olympic sports) are less frequently cited than, for example, triathlon. One may speculate that more energyreliant sports may benefit to a greater extent from general scientific support/knowledge (i.e., exercise physiology) than the more "technical" sports (i.e., motor control). This suggestion is corroborated by the importance of the "physiology" research topic (see chapter 8 and Figure 6 ) across most sports. However, the limitation of our search to PubMed and the biomedical literature may partially account for this result. It is very challenging to clearly appreciate why a sport attracts the interest of sport scientists. We do not exclude the possibility that this effect can be explained by more general factors (e.g., a general increase in publication numbers in recent decades). Olympic sports may be of higher scientific interest to sport scientists than non-Olympic sports. This may be related to a trend of scientific support increasingly becoming a key component of elite performance. Many scientists of excellent scientific/academic background (i.e., Dupont et al., 2005; Bangsbo et al., 2008 in football, Mountjoy et al., 2016 Mujika et al., 2019 in swimming, Mujika et al., 2019 in athletics, Jones et al., 2021 in distance running, and Hebert-Losier et al., 2017 Solli et al., 2017 in Nordic skiing, to name only a fewwe apologize to many other colleagues who deserve to be on this list) are indeed servicing and advising elite athletes or teams while in parallel producing outstanding scientific research that is sometimes relevant for coaches. Until recently, the translation of "sport sciences" research to practice was often poor (Bishop, 2008) , and interdependence between the practical and scientific impacts of "sport sciences" research has frequently been advocated (Coutts, 2016; Brocherie and Beard, 2020) . Elite sports organizations require embedded, fast-moving, serviceproviding applied research scientists as well as slow-thinking researchers (Sandbakk, 2018) , who, working together, will carry on producing sport-specific research. Most elite sports institutes (e.g., Insep in France https:// labos-recherche.insep.fr/fr), the IOC (https://olympics.com/ FIGURE 2 | Number of citations per year (y-axis) in four "recent" (i.e., debut at 1998 or later) Olympic sports. The date of the Olympic debut is marked by an arrow. ioc/medical-and-scientific-commission) and some National Olympic Committees and national and international governing bodies (e.g., World Athletics https://www.worldathletics.org/ about-iaaf/health-science) have developed scientific committees to stimulate research on specific topics according to their needs. Examples are programmes with the aim of implementing new rules for the protection of athletes' health by limiting concussion (Stokes et al., 2021) or heat stress (Mountjoy et al., 2012) . Although the scientific support and service sector has grown tremendously in the last two decades, the impact of scientific support on sports performance remains difficult to quantify. However, while we believe that sport-specific attractiveness is due mainly to the importance of the sport itself, it is beyond the scope of the present review to relate the present bibliometric information to other sport characteristics, such as but not limited to the number of participants, economic weight and media exposure. These points are briefly discussed in the present review but certainly also contribute to the importance of a particular sport in the scientific literature. The quality of servicing scientists at the club, federation, or sport institute levels may be a factor of influence, but the vast majority of these sports publications seem to have come from academic (i.e., employed by universities or research organizations) researchers. With the evolution of the performance support model within the professional and elite sporting environment, deemed necessary to integrate an applied research process to bridge the gap between scientists and practitioners (Brocherie and Beard, 2020) , the scientific publication landscape may change in the future, even for less attractive sports. The dominance of football in the "sport sciences" literature is impressive. Football represents 19.7 and 26.3% of the total number of articles and citations, respectively (Figure 3) , despite its relatively low importance with regard to Olympic medal counts (i.e., 2 of 339 gold medals at Tokyo 2020 vs. 48 in athletics, 37 in swimming and 12 in Nordic skiing or skating at Beijing 2022, to cite only the main Olympic sports). The reasons, therefore, are unrelated to the Olympics and likely are attributable to its general popularity and associated economic characteristics. Football is the most popular sport worldwide (e.g., the global audience at the FIFA World Cup 2018 was estimated to be 3.57 billion people). Half of the total revenue of the sports industry is gained by competitive sports of the spectator sports sector, amounting to approximately US$250 billion in turnover each year. The share of football accounts for an estimated 43% of this revenue and thus is much larger than the shares of other Olympic sports or even of other US professional sports; it is almost equal to the combined revenue from all US sports, including American football (13%), baseball (12%), Formula 1 auto racing (7%), basketball (6%), ice hockey (4%) and tennis (4%) (https://www.researchandmarkets. com/reports/5022446/sports-global-market-report-2020- 30-covid-19). While our findings are in line with previous results (Brito et al., 2018) , the consequences and implications of the scientific dominance of football remain unclear. It is tempting to relate such scientific proliferation to the already well-organized performance support services within professional and elite football (Brocherie and Beard, 2020) . However, to our knowledge, there has been no comprehensive analysis of the number of scientists working in professional football, even if it is obvious that this segment has grown considerably in the last decade, especially in the clubs of the five major football leagues in Europe (i.e., England, Spain, Germany, Italy, and France). This may have provided an edge over many other sports that are still in the process of establishing efficient structures (e.g., some leading US sports league franchises) (Brocherie and Beard, 2020) . Several North American professional sports are highly ranked in terms of bibliometrics. As for football, it is likely that the economic characteristics of the main North American national leagues (Major League Baseball, National Basketball Association, and National Hockey League (estimated at 5.5, 4.6, and 2.2 billion US dollars in 2015, respectively; https://www.ameriresearch. com/global-football-sports-market/) may be one reason for the scientific interest in these sports. Moreover, "sport sciences" is a well-established academic discipline, and the USA is a leading contributor in this field, as is exemplified by the largest "sport sciences" society worldwide, American College of Sports Medicine (ACSM) (www.acsm.org), with more than 50,000 members and certified professionals from 90 countries around the globe. In line with other team sports (e.g., volleyball, handball, and field hockey), publications related to injuries (prevention and rehabilitation) are relatively more important in team sports (>20% of the total sport-specific articles; Figure 6 ) than in the main individual sports (cycling, athletics, swimming, distance running-marathon, etc.). This may stem from a higher degree of professionalization and therefore specialization of permanent full-time medical staff in team sports due to the economic power of these sports and the financial value of professional players. Despite some parts of the world being particularly passionate about winter sports (e.g., Sweden and Norway for Nordic skiing, Russia and Canada for ice hockey, and Austria and Switzerland for alpine skiing), the audience for winter sports and number of participants remain comparatively low worldwide. This is likely due primarily to geographical and climatic limitations (i.e., especially the lack of snow) for the development of winter sports. The lower importance of winter sports becomes clear when comparing the latest summer and winter Olympic games. A record number of 2,922 athletes from 92 countries participated in the Pyeongchang 2018 Winter Games, while 11,362 athletes from 204 countries participated in the Rio de Janeiro 2016 Summer Games. A similar discrepancy is observed with regard to the number of sports and disciplines, with 102 events in 7 sports (and 15 disciplines) at the 2018 winter Olympic games vs. 306 events in 28 sports and 43 disciplines at the 2016 summer games. In the European Nordic countries, sport sciences have a long tradition of excellence, owing primarily to the work of famous pioneers in exercise physiology (e.g., Saltin and Astrand, 1967) who performed early studies, including some on Nordic skiers. This might partly explain why Nordic skiing is the second most cited winter sport (after ice hockey-see above). Six journals of 116 included in our search (J Strength Cond Res, 10.0%; J Sports Sci, 7.7%; J Sports Med Phys Fitness, 6.2%; Br J Sports Med, 5.5%; Int J Sports Med, 5.3%; and Med Sci Sports Exerc, 5.2%) contained 40% of all analyzed publications. These leading journals publish articles predominantly on applied research as well as on conditioning or training and testing (e.g., J Strength Cond Res, J Sports Med Phys Fitness, and J Sports Sci). Some are tightly connected to powerful organizations (e.g., Br J Sports Med, which regularly publishes reports or statements of the IOC, or Med Sci Sports Exerc, which belongs to the ACSM). Our search included 116 journals, but many of them do not publish "biomedical" articles (accessible in PubMed) specific to any of the Olympic sports. The scope of some journals is very broad (e.g., applied physiology in J Appl Physiol) or very narrow (e.g., High Alt Med Biol); articles focusing on one given sport in those journals are thus less frequent. Many journals are furthermore relatively new in PubMed (e.g., Int J Sports Physiol Perf and Front Sports Active Living). Finally, the fact that most articles are published in only a few journals may render questionable the profusion of (too?) many journals in the "sport sciences" field, which has been growing since the early 2000's. We scrutinized whether the Olympic entrance of the "recent" Olympic sports (e.g., inserted in the Olympic programme in the last 25 years: snowboard in 1998; trampoline, triathlon, and taekwondo in 2000; rugby sevens in 2016; and surfing, karate, sport climbing, and skateboarding in 2020), might have impacted their specific scientific attractiveness. Figure 2 shows the evolution of yearly citation numbers between 1990 and 2020 with the date of the entrance into the Olympic programme for four "recent" sports (snowboard, triathlon taekwondo, and rugby sevens). Whether entrance into the programme has a positive effect remains unclear, even if an increase in the publication rate is observable 6-8 years after (for snowboard and taekwondo) or several years before (as is clearly shown for rugby sevens and triathlon) nomination as an Olympic sport. Overall, the "Olympic legacy" does not seem to stimulate a large increase in the volume of articles or citations (Thomas et al., 2016) . Of these "recent" Olympic sports, triathlon is by far the most productive of scientific output (Figure 2) . As discussed in chapter 1, this may stem from the nature of the sport, which is highly energetic and of interest to physiologists, while other "recent" sports are less aerobic. Sports carry strong cultural and political meanings for their practitioners and spectators and powerfully symbolize identities and communities (Millet and Giulianotti, 2019) . It is therefore not surprising-and in a sense reassuring in our globalized world-to find that a local sporting culture can impact the scientific output, as is testified by the overrepresentation of alpine and Nordic skiing in Scand J Med Sci Sport. "Sport sciences" (like most other scientific fields) are dominated by Anglo-Saxon countries (especially the USA, UK, Australia, and Canada). As has recently been observed (Pyne, 2021) , research in several of the world's leading sporting nations (e.g., Russia, China, Japan, and South Korea; all top 8 nations at the 2016 Summer Olympic Games) is underrepresented in "sport sciences" journals that are published mostly in English. It is beyond the scope of this review to analyze all the other potential factors or barriers (economic, political, religious, gender based, etc.) that bias the over-vs. under-representation of a given sport in the "sport sciences" literature, but more cultural, geographical and gender diversity is needed. Another observation is the influence of the composition of the editorial boards of the journals on editorial policy as well as the published content. All the above-mentioned factors influence regular publications on certain sports in journals, such as rugby sevens in Int J Sports Physiol Perf or tennis in Br J Sports Med, while some sports that are extremely popular in Asia (taekwondo and table tennis) lack comparable platforms for scientific exchange. We analyzed the relative distribution of six research topics (i.e., physiology, performance, training and testing, injuries and medicine, biomechanics, and psychology) across all summer and winter Olympic sports publications since the analysis may provide informational particularities that are especially relevant for research on these sports or on the determinants of performance, which vary considerably among sports. For example, it has long been known that maximal aerobic power is paramount in cross-country skiing, cycling, distance running and rowing, as is evidenced by the high maximal oxygen consumption (VO 2max ) values in top performers in these sports (Haugen et al., 2018) , who reach VO 2max values of >90 ml/kg/min (Millet and Jornet, 2019) . Although "physiology" covers other aspects than aerobic capacity, many publications (approximately twothirds) on sports such as triathlon, swimming, and walking concern physiological aspects due to these sports' high reliance on aerobic capacities. Whereas, the scientific literature on many sports is dominated by physiological topics, research on other sports focuses on associated injuries-illnesses. The topic "injuries and medicine" is paramount (i.e., > 40% of related publications) in five summer (baseball, boxing, equestrian, skateboarding, and softball) and 4 winter (alpine freestyle skiing, curling, ice hockey, and snowboarding) sports. Of the publications, 65% of those on skateboarding and 82% of those on snowboarding concern injuries. Deeper analyses of these publications are required to differentiate the types and causes of injuries between contact sports (e.g., boxing and ice hockey), sports inducing falls (equestrian, alpine skiing, snowboarding, and skateboarding), and sports inducing overuse injuries (e.g., elbow injury in baseball and softball). The "injuries and illnesses prevention and incidence" topic is of the highest priority in elite sports; the IOC medical and scientific commission (https://olympics. com/ioc/medical-and-scientific-commission) publishes regular reports on injuries and illness incidences in the summer (Soligard et al., 2017) and winter (Soligard et al., 2019) Olympic games. During the last summer games in Rio de Janeiro in 2016, the injury incidence ranged from 38% in BMX cycling to 0-3% in canoeing, rowing, shooting, archery, swimming, golf, and table tennis, while the illness incidence was 10-12% in diving, swimming, sailing, canoeing-kayaking and equestrian (Soligard et al., 2017) . During the last winter games in Pyeongchang in 2018, the injury incidence was highest (20-28%) in freestyle skiing and snowboarding and lowest (2-6%) in Nordic combined, biathlon, snowboard slalom, moguls, and cross-country skiing. The illness incidences ranged between 13 and 15% in biathlon, curling, bobsleigh, and snowboard slalom (Soligard et al., 2019) . Surprisingly, in every sport, the number of publications on psychology-related topics is quite low. Only for curling, shooting, and modern pentathlon are >10% of the sport-specific publications related to psychology, followed by table tennis. All these sports require extreme accuracy and self-control. The possibility that this low representation of psychological articles relates to the applied methodology (e.g., the database searched was PubMed) cannot be excluded, but most of the leading sport psychology journals (e.g., Journal of Sport & Exercise Psychology) were included in our search. These findings thus could also indicate that sport psychology is less represented than other scientific areas (physiology, medicine) in the literature. The potential underrepresentation of sport psychology should encourage sport psychologists or mental coaches to publish more of their research since there is no doubt that mental skills are an important aspect of performance in all sports. The main strength of this review is the exhaustive bibliometric analysis and review across all Olympic sports. To our knowledge, no similar work is available to date. The volume of extracted articles, the clear delimitation of journals and sports and the subsequent analysis permitted us to extract information on how the "sport sciences" field is structured and organized to characterize the research body on Olympic sports and highlight sports-related differential peculiarities, developments and limitations of the scientific literature. Some limitations must be acknowledged. First, the search was performed only in the titles of the articles and did not include searching abstracts, keywords or text. Since our aim was to compare the literature on individual sports, this method may be better suited to extracting articles related primarily to one sport without risking the inclusion of false positives that refer to specific sports only marginally or incidentally. Not all physiology or medical articles on "athletes" were included since these articles can also refer to non-specific physiological responses or mechanisms. Instead, we targeted each sport or the athletes of that sport and applied clear exclusion criteria to enhance the specificity of the search strategy. However, minor categorization inaccuracies due to the high volume of articles analyzed, particularly in the "football" and "athletics" categories, cannot be ruled out. All American and Canadian publications on football in particular were checked individually to accurately distinguish between soccer and American football. If publications could not be unambiguously classified, they were excluded. For "athletics, " the single "athlete" item in the title would have led to 10,866 publications, most of which were not related to "athletics" ( Table 3 ). In an alternative search, specific terms related to athletics (e.g., javelin and relay) were merged, yielding a sufficiently accurate outcome. Similarly, articles with the generic term "repeated sprints" were included only if one sport was clearly mentioned in the title. There is also potential for a biased bibliometric analysis because some articles published on topics other than "exercise and sport sciences" or general medical and basic science journals could not be excluded (e.g., Olympic sports-related sociology), possibly leaving out influential works. Therefore, the present bibliometric analysis should be interpreted in light of these limitations. Using our approach, it was not possible to differentiate research on high-level exercise from (everyday) physical activities. This limitation applies in particular to sports that occur in parallel in common everyday activities, such as walking or cycling. These categories are therefore likely overrepresented in our analysis in comparison to sports that are practiced only for competitive purposes and therefore are less frequently treated in the scientific literature. It is noteworthy that despite this bias, football still dominates the "sport sciences" field. The absolute bibliometric is by definition correct only at the date of the search. We decided to report these absolute metrics (and not only the relative percentage values) for clarity and because it might help the reader to search beyond the top 5 articles for each sport displayed in Tables 4, 5. One additional limitation was the descriptive nature of the analysis and the lack of statistical treatment of the data. The descriptive nature of the present article was thought to be more appropriate for the 8 main outcomes presented in the discussion. The peculiarities in significant differences in the number of citations between sport A and sport B are of negligible importance and might distract the reader from the main points. Finally, a more fundamental criticism of the applied approach concerns the importance attached to numbers of citations generated by peer-reviewed publications as a metric for assessing the research impact (Buttner et al., 2021) . For the present review, general quantitative publication metrics were used to assess only the importance of the different sports in the scientific literature in this respect. Measuring and comparing the "quality" of science between sports are challenges for future research. We are aware that the use of the top 10 most cited articles (mean, max and min citations; Figure 4) in every sport as a metric of research quality is far from optimal. Our findings show that many factors are likely involved in determining the importance of a sport-specific scientific interest, and we do not intend to understate the importance of research that is impactful in terms of policy, economics and society. Finally, it would be interesting to relate the bibliometric data presented here to the economic weight and media exposure of these sports or the number of participants in them worldwide. Such analyses may provide further insights into why certain sports are more prominently represented in the scientific literature than others. The high scientific impact of publications, for example, on football (i.e., more articles and citations), likely does not reflect "better" scientific quality than that of publications on a less prominent sports. The bibliometric analysis of all articles related to summer and winter Olympic sports published in the "sport sciences" literature provides novel insights into this research field, converging on eight key points: 1. nine sports (football, cycling, athletics, swimming, distance & marathon running, basketball, baseball, tennis, and rowing) were involved in 69% of the articles and 75% of the citations; 2. football (soccer) is the leading sport, with 19.7 and 26.3% of the total number of articles and citations, respectively; 3. team sports, especially American professional sports (i.e., baseball, basketball, and ice hockey), are the focus of prominent scientific output; 4. overall, winter sports generate comparatively minor scientific interest; 5. the greatest number of studies in the field are published in a relatively small number of "sport sciences" journals; 6. entrance into the Olympic programme may increase the scientific output of "recent" sports, although this hypothesis requires further substantiation; 7. local/cultural influences contribute to the representation of different sports in a journal's portfolio; and 8. finally, the relative distribution of six main research topics (i.e., physiology, performance, training and testing, injuries and medicine, biomechanics, and psychology) is extremely diverse across sports and provides information on the performance determinants of each sport. Overall, within the rapidly growing interdisciplinary "sport sciences" field, this bibliometric analysis provides valuable and helpful information for researchers, practitioners, and funding stakeholders to achieve future progress in the Olympic-based research agenda. The original contributions presented in the study are included in the article/supplementary materials, further inquiries can be directed to the corresponding author/s. Isokinetic muscle strength and hiking performance in elite sailors. Scand Morphological characteristics of Olympic sprint canoe and kayak paddlers Anterior cruciate ligament injury in national collegiate athletic association basketball and soccer: a 13-year review Sports medicine and sailing Analysis of sprint cross-country skiing using a differential global navigation satellite system Knee injury patterns among men and women in collegiate basketball and soccer. NCAA data and review of literature The need of a weight management control program in judo: a proposal based on the successful case of wrestling The relationship between maximal oxygen uptake and repeated sprint performance indices in field hockey and soccer players Incidence of acute volleyball injuries: a prospective cohort study of injury mechanisms and risk factors. Scand A twofold reduction in the incidence of acute ankle sprains in volleyball after the introduction of an injury prevention program: a prospective cohort study. Scand Skateboard and inline skate fractures: a report of one summer's experience The Yo-Yo intermittent recovery test: a useful tool for evaluation of physical performance in intermittent sports Back pain and degenerative abnormalities in the spine of young elite divers: a 5-year follow-up magnetic resonance imaging study Biomechanics of windmill softball pitching with implications about injury mechanisms at the shoulder and elbow Increasing functional variability in the preparatory phase of the takeoff improves elite springboard diving performance Anaerobic power and muscle strength characteristics of 11 years old elite and non-elite boys and girls from gymnastics, team handball, tennis and swimming. Scand Anaerobic threshold, individual anaerobic threshold, and maximal lactate steady state in rowing Energetics of karate kumite Specific aspects of contemporary triathlon: implications for physiological analysis and performance Mechanisms of anterior cruciate ligament injury in World Cup alpine skiing: a systematic video analysis of 20 cases Injury type and incidence among elite level curlers during world championship competition Interval training for performance: a scientific and empirical practice. Special recommendations for middle-and longdistance running. Part I: aerobic interval training Energy specificity of rock climbing and aerobic capacity in competitive sport rock climbers An applied research model for the sport sciences The influence of pacing strategy on VO2 and supramaximal kayak performance Australian snowboard injury data base study. A four-year prospective study Modeling and inverse simulation of somersaults on the trampoline Aetiology and occurrence of diving injuries. A review of diving safety From bikinis to boardshorts: wahines and the paradoxes of surfing culture The sports science of curling: a practical review Comparison of static and dynamic balance in female collegiate soccer, basketball, and gymnastics athletes Physical and physiological profiles of taekwondo athletes Top 50 mostcited articles in medicine and science in football All alone we go faster, together we go further: the necessary evolution of professional and elite sporting environment to bridge the gap between research and practice Enhancement of 2000-m rowing performance after caffeine ingestion Talent identification and deliberate programming in skeleton: ice novice to Winter Olympian in 14 months Acute effect of whole-body vibration on sprint and jumping performance in elite skeleton athletes Effect of long haul travel on maximal sprint performance and diurnal variations in elite skeleton athletes Effects of modern ski equipment on the overall injury rate and the pattern of injury location in Alpine skiing Counting publications and citations is not just irrelevant: it is an incentive that subverts the impact of clinical research Analysis of the characteristics of competitive badminton An epidemiologic investigation of injuries affecting young competitive female gymnasts The effects of a motivational general-mastery imagery intervention on the sport confidence of high-level badminton players Energy demands in taekwondo athletes during combat simulation Bone mineral density in elite 7-to 9-yr-old female gymnasts and swimmers Quiet eye duration and gun motion in elite shotgun shooting Physical and physiological profile of elite karate athletes Leg power and hopping stiffness: relationship with sprint running performance Acute whole body vibration training increases vertical jump and flexibility performance in elite female field hockey players Running economy and distance running performance of highly trained athletes Effects of repeated days of intensified training on muscle glycogen and swimming performance Energy expenditure during front crawl swimming: predicting success in middle-distance events Critical evaluation of food intake and energy balance in young modern pentathlon athletes: a crosssectional study Working fast and working slow: the benefits of embedding research in high performance sport Monitoring changes in performance, physiology, biochemistry, and psychology during overreaching and recovery in triathletes Physiological and biomechanical factors associated with elite endurance cycling performance Cycling efficiency is related to the percentage of type I muscle fibers Relationships of stroke rate, distance per stroke, and velocity in competitive swimming Osseous adaptation and range of motion at the glenohumeral joint in professional baseball pitchers Upper-body anthropometric and strength measures and their relationship to start time in elite luge athletes Injuries in the sport of luge Volume of training and the ranking level are associated with the leakage of urine in young female trampolinists Influence of the postion of crew members on aerodynamics performance of two-man bobsleigh Biomechanical analysis of the change in pistol shooting format in modern pentathlon Food restriction, performance, biochemical, psychological, and endocrine changes in judo athletes Energy demands during a judo match and recovery Energy expenditure of horse riding Effect of practice on brain activity: an investigation in top-level rifle shooters Energetics of karate (kata and kumite techniques) in top-level athletes Relationship between oxygen uptake kinetics and performance in repeated running sprints Relation between multidimensional performance characteristics and level of performance in talented youth field hockey players Prevalence of stress incontinence in nulliparous elite trampolinists. Scand Glenohumeral joint total rotation range of motion in elite tennis players and baseball pitchers Postural stability and skilled performance-a study on top-level and naive rifle shooters Activation patterns in forearm muscles during archery shooting A method to help reduce the risk of serious knee sprains incurred in alpine skiing Influence of the distance in a roundhouse kick's execution time and impact force in Taekwondo Physiological demands of competitive surfing Physiological characteristics of badminton match play Intensity of tennis match play Knee ligament injuries in volleyball players Kinetics of baseball pitching with implications about injury mechanisms Kinematic and kinetic comparison of baseball pitching among various levels of development Injuries among male and female World Cup alpine skiers Valgus knee motion during landing in high school female and male basketball players Skateboarding injuries of today Evidence for restricted muscle blood flow during speed skating Skateboarding injuries Physiological profiles of elite judo athletes Acute injuries in recreational and competitive surfers: incidence, severity, location, type, and mechanism Endurance and neuromuscular changes in world-class level kayakers during a periodized training cycle Power production by Olympic weightlifters Trends and topics in sports research in the Social Science Citation Index from 1993 to Asymptomatic Achilles, patellar, and quadriceps tendinopathy: a longitudinal clinical and ultrasonographic study in elite fencers Salivary IgA levels and infection risk in elite swimmers Differences in physical fitness and throwing velocity among elite and amateur male handball players Coping strategies used by U.S. Olympic wrestlers Coping strategies used by national champion figure skaters Anthropometric, strength, endurance and flexibility characteristics of elite and recreational climbers Relative vs. absolute physiological measures as predictors of mountain bike cross-country race performance High prevalence of atrial fibrillation in long-term endurance cross-country skiers: echocardiographic findings and possible predictors-a 28-30 years follow-up study Force-time curve characteristics of dynamic and isometric muscle actions of elite women olympic weightlifters Applied physiology of rowing Effects of rapid weight loss on mood and performance among amateur boxers Serum enzyme levels after bobsled racing New records in human power Factors that influence the performance of elite sprint cross-country skiers A threeweek traditional altitude training increases hemoglobin mass and red cell volume in elite biathlon athletes Musculo-skeletal loading conditions at the hip during walking and stair climbing Oxygen uptake during maximal treadmill and bicycle exercise Moment-length relations of rectus femoris muscles of speed skaters/cyclists and runners Movement patterns in rugby sevens: effects of tournament level, fatigue and substitute players Physiological, anthropometric, and performance characteristics of rugby sevens players The physiological basis of athletic records Sports science Maximal strength training improves work economy in trained female cross-country skiers Biathlon shooting performance after exercise of different intensities Biomechanical analysis of double poling in elite cross-country skiers Does performance of hang power clean differentiate performance of jumping, sprinting, and changing of direction? Brain injury forces of moderate magnitude elicit the fencing response How boxers decide to punch a target: emergent behaviour in nonlinear dynamical movement systems Trampoline injury in New Zealand: emergency care The role of biomechanics in maximising distance and accuracy of golf shots Relationships between ground reaction force impulse and kinematics of sprint-running acceleration Kinematics of table tennis topspin forehands: effects of performance level and ball spin Use of RPE-based training load in soccer Nutrition for endurance sports: marathon, triathlon, and road cycling Physiological demands of running at 2-hour marathon race pace A profile of olympic taekwondo competitors Systematic review and meta-analysis of reduction in all-cause mortality from walking and cycling and shape of dose response relationship A bibliometric analysis of the top cited articles in sports and exercise medicine Snowboarding injuries: trends over time and comparisons with alpine skiing injuries Authorship and sampling practice in selected biomechanics and sports science journals Mechanisms for noncontact anterior cruciate ligament injuries: knee joint kinematics in 10 injury situations from female team handball and basketball Epidemiology of injury in elite and subelite female gymnasts: a comparison of retrospective and prospective findings The physiological demands of table tennis: a review Physiological and performance responses to tournament wrestling Characteristics of national and world class female pentathletes Use of protective equipment by adolescents in inline skating, skateboarding, and snowboarding Mechanisms of anterior cruciate ligament injury in basketball: video analysis of 39 cases Knee and ankle joint stiffness in sprint running A biomechanical analysis of common lunge tasks in badminton Arthroscopic treatment of an avulsion fracture of the ligamentum teres of the hip in an 18-year-old horse rider The influence of electrocortical biofeedback on performance in pre-elite archers Physiological demand and pacing strategy during the new combined event in elite pentathletes Performance factors in the new combined event of modern pentathlon Physiological characteristics of successful mountain bikers and professional road cyclists The importance of walking to public health Development of a measurement and feedback training tool for the arm strokes of high-performance luge athletes Biomechanical study of the final push-pull in archery The effects of season-long vitamin D supplementation on collegiate swimmers and divers Velocity specificity of weight training for kayak sprint performance Riding and other equestrian injuries: considerable severity Two-man bobsled push start analysis Pre-shot EEG alpha-power reactivity during expert air-pistol shooting: a comparison of best and worst shots Notational analysis of elite and sub-elite water polo matches Effect of pitch type, pitch count, and pitching mechanics on risk of elbow and shoulder pain in youth baseball pitchers Decreased salivary immunoglobulin A secretion rate after intense interval exercise in elite kayakers The validity of a non-differential global positioning system for assessing player movement patterns in field hockey Effects of front and dual suspension mountain bike systems on uphill cycling performance Shoulder injuries in archery Descriptive epidemiology of collegiate women's softball injuries: National Collegiate Athletic Association Injury Surveillance System A naturalistic study of the directional interpretation process of discrete emotions during high-stakes table tennis matches Taekwondo: Physiological responses and match analysis Equestrian injuries Isokinetic torque imbalances in the rotator cuff of the elite water polo player Activity profile of worldclass professional surfers during competition: a case study Physiological and anthropometric determinants of sport climbing performance Biomechanics of sprint running. A review Sports and active living are medicine, and education, happiness, performance, business, innovation, and culture for a sustainable world On top to the top-acclimatization strategy for the "fastest known time" to mount everest Physiological differences between cycling and running: lessons from triathletes Alterations of neuromuscular function after prolonged running, cycling and skiing exercises Efficacy of platelet-rich plasma for chronic tennis elbow: a double-blind, prospective, multicenter, randomized controlled trial of 230 patients Match performance of highstandard soccer players with special reference to development of fatigue Relationships between postural balance, rifle stability and shooting accuracy among novice rifle shooters. Scand Mood disturbance following increased training in swimmers Reaction times and anticipatory skills of karate athletes An approximate simulation model for initial luge track design Hyperthermic-related challenges in aquatics, athletics, football, tennis and triathlon Consensus statement on the methodology of injury and illness surveillance in FINA (aquatic sports) Contemporary periodization of altitude training for elite endurance athletes: a narrative review Prevention of anterior cruciate ligament injuries in female team handball players: a prospective intervention study over three seasons A prospective cohort study of anterior cruciate ligament injuries in elite Norwegian team handball. Scand Windsurfing injuries: results of a paperand Internet-based survey Effects of ballistic training on preseason preparation of elite volleyball players Infectious episodes in runners before and after the Los Angeles Marathon Relationship between strength, power, speed, and change of direction performance of female softball players Elbow tendinosis/tennis elbow Trampoline injuries A notational analysis of elite tennis strategy Health benefits of cycling: a systematic review. Scand A study on the excreted catecholamines in the urine of Bobsleigh-tobogganing contestants Injury mechanisms for anterior cruciate ligament injuries in team handball: a systematic video analysis Risk factors for shoulder and elbow injuries in adolescent baseball pitchers American College of Sports Medicine position stand. Weight loss in wrestlers Boxing and running lead to a rise in serum levels of S-100B protein Rider injury rates and emergency medical services at equestrian events Muscle function in elite master weightlifters Effects of focus of attention depend on golfers' skill Judo, better than dance, develops sensorimotor adaptabilities involved in balance control Arthroscopic labral repair and treatment of femoroacetabular impingement in professional hockey players The science of badminton: game characteristics, anthropometry, physiology, visual fitness and biomechanics Snowboard injuries Performancedetermining physiological factors in the luge start Heart rate variability in elite triathletes, is variation in variability the key to effective training? A case comparison Star Excursion Balance Test as a predictor of lower extremity injury in high school basketball players The reliability and validity of a novel sport-specific balance test to differentiate performance levels in elite curling players The incidence of anterior cruciate ligament injuries among competitive Alpine skiers: a 25-year investigation Growing the international reach and accessibility of IJSPP Improving the 'how' and 'what' decisions of elite table tennis players Stress fracture of the ulna in an elite bobsled brakeman Anthropometric and physiological predispositions for elite soccer A pilot biomechanical assessment of curling deliveries: is toe sliding more likely to cause knee injury than flatfoot sliding? Head, eye and arm coordination in table tennis The science of fencing: implications for performance and injury prevention The efficacy of wrist protectors in preventing snowboarding injuries The effects of fatigue on decision making and shooting skill performance in water polo players Treadmill roller ski test predicts biathlon roller ski race results of elite U.S. biathlon women Physiological characteristics and performance of top U.S. biathletes The validity and reliability of a novel activity monitor as a measure of walking Hemispheric asymmetry, cardiac response, and performance in elite archers Maximal oxygen uptake in athletes Let's close the gap between research and practice to discover new land together! Int Anthropometric and physical abilities profiles: US National Skeleton Team A bibliometric analysis of sport economics research Practical knowledge in expert coaches: on-site study of coaching in sailing Paralysis from sport and diving accidents Physiological and biomechanical aspects of rowing. Implications for training The effects of mountain bike suspension systems on energy expenditure, physical exertion, and time trial performance during mountain bicycling Shoulder range of motion, pitch count, and injuries among interscholastic female softball pitchers: a descriptive study Do physical maturity and birth date predict talent in male youth ice hockey players? A bibliometric analysis of four sport management journals Onset of blood lactate accumulation and marathon running performance Applied physiology of water polo Development of a boxing dynamometer and its punch force discrimination efficacy Olympic Winter Games: a prospective study of 2914 athletes from 92 countries Olympic Summer Games: A prospective study of 11274 athletes from 207 countries The Training characteristics of the world's most successful female cross-country skier Time-motion analysis of elite field hockey, with special reference to repeated-sprint activity Workload demands in mountain bike racing Patterns of weight loss and regain in wrestlers: has the tradition changed? Does reducing the height of the tackle through law change in elite men's rugby union (The Championship, England) reduce the incidence of concussion? A controlled study in 126 games Physiology of soccer: an update Curling for confidence: psychophysical benefits of curling for older adults Positional differences in match running performance and physical collisions in men rugby sevens Running demands and heart rate response in rugby sevens referees Neural correlates of attentional and executive processing in middle-age fencers Effects of rugby sevens matches on human neutrophil-related nonspecific immunity Spinal injuries in skiers and snowboarders The Olympic legacy: Journal metrics in sports medicine and dentistry Shortterm effects on lower-body functional power development: weightlifting vs. vertical jump training programs The anthropometrical and physiological characteristics of elite water polo players The association of hip strength and flexibility with the incidence of adductor muscle strains in professional ice hockey players Low back pain in professional golfers: the role of associated hip and low back range-of-motion deficits Incidence and determinants of lower extremity running injuries in long distance runners: a systematic review Optimisation of sprinting performance in running, cycling and speed skating A one season prospective cohort study of volleyball injuries Performing under pressure: the effects of physiological arousal, cognitive anxiety, and gaze control in biathlon Assessment of aerobic and anaerobic demands of dinghy sailing at different wind velocities Inspiratory muscle training improves rowing performance Biomechanics of the head for Olympic boxer punches to the face Physiology of difficult rock climbing Anthropometric profiles of elite male and female competitive sport rock climbers Physiological effects of a weight loss regimen practiced by college wrestlers Kinematics and kinetics of elite windmill softball pitching Response timing and muscular coordination in fencing: a comparison of elite and novice fencers Converging evidence for the underreporting of concussions in youth ice hockey Using squat testing to predict training loads for lower-body exercises in elite karate athletes The learning advantages of an external focus of attention in golf An external focus of attention enhances golf shot accuracy in beginners and experts Relationship between strength qualities and sprinting performance Pediatric fractures during skateboarding, roller skating, and scooter riding Relationship between push phase and final race time in skeleton performance All authors listed have made a substantial, direct and intellectual contribution to the work, and approved it for publication. The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.