A systematic literature search was performed on PubMed, SURF, Web of Science (Core Collection), APAPsychInfo, and SPORTDiscus on July 25, 2025. The selection of databases was determined to cover a wide range of sport-specific disciplines. The literature search followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines (28). Search-terms are presented in Supplementary Table S1. The free version of the program Rayyan (29) was used to facilitate and optimize the review process. The screening process was performed by two researchers who were blinded to the work of the other. After completing the screening process, remaining conflicts were resolved through discussion.

Studies were included into the general analysis if they (a) focused on climbing performance-related and determining factors, (b) included a representative sample of human lead climbers, speed climbers, and/or boulderers, and (c) included climbers based on the classification of Draper et al. (30). More precisely, we included participants with a minimum climbing level of 15 or 18 (advanced) on the International Rock Climbing Research Association (IRCRA) reporting scale (30) for females and males, respectively. Studies that also included participants below these performance levels were considered if their data were analyzed in relation to climbing level. The IRCRA scale was chosen to classify athletes' performance level because of its prominence in the climbing community and its internationally recognized framework for categorizing climbing ability. The IRCRA system provides standardized conversions across different national and discipline-specific grading scales, allowing for consistent comparison between studies that use different rating systems. Additionally, it allows for rating climbers irrespective of sex and age. The detailed analysis was based exclusively on the data relating to the included category. Youth athletes are frequently overlooked in climbing research, a limitation that has been highlighted repeatedly (31). Therefore, to fully cover professional climbing, studies including participants under the age of 18 were also included in the review. However, as it is not possible to directly compare young athletes with adults (31), these studies were analyzed in a separate category (Youth athletes). Only peer-reviewed original studies published in English or German were considered. Animal based research, as well as studies focusing on mountaineering and/or outdoor climbing were not included into this review. If full texts were not available online, the authors were contacted directly. If they were not able to share the full text within three weeks, the publication was excluded from this review. For the detailed analysis of sex-specific differences in advanced to higher-elite climbing, a subsample was extracted from the previously identified studies. This included all studies that had conducted a quantitative analysis of sex-specific differences in performance-related or performance-determining factors.

For the general analysis, the data extracted from all studies included participant characteristics (number, discipline, sex, age, and performance level). Specifically, we recorded the number of studies that focused exclusively on male or female participants, as well as those that included both sexes, and noted whether sex-specific analyses were conducted. The number of male and female participants were reported both in total and according to the climbing discipline. Furthermore, the distribution of participant sexes across the climbing disciplines was analyzed. To allow comparison of the results between studies, reported grades for climbing and bouldering performance were transformed according to the IRCRA scale (30). For the detailed analysis, studies that conducted sex-specific analyses were categorized according to performance-related and determining factors based on current literature (10, 13, 22, 25, 32) including energetically determined factors; flexibility; cognitive function and psychological abilities; coordination, skills, and technique; nutrition and energy availability; anthropometry; competition analysis; training and adaptations; injuries and mental health; and youth athletes. In addition, the methodological quality of the studies included in the detailed analysis was evaluated using the AXIS tool (33), a critical appraisal tool for cross-sectional studies. Each of the 20 AXIS items was rated as either positive (assigned a score of 1) or negative (assigned a score of 0). Three independent raters were assigned subsets of the identified studies so that each study was ultimately evaluated by two raters, resolving any discrepancies in a consensus meeting. Items 7, 13, and 14 were excluded from the evaluation, as all three items relate to experimental designs and were therefore not applicable to any of the included studies. Consequently, the maximum possible score was 17. Predefined percentage thresholds were used to categorize study quality, with scores ≥ 70% (≥12 points) indicating high quality, scores between 60.0% and 69.9% (10–11 points) indicating fair quality, and scores < 60% (<10 points) indicating low quality, following Rovito et al. (34).

Of the 246 studies included in the general analysis, 102 studies included only male participants (41.5%) compared to 8 studies, which included only female participants (3.3%). 109 studies included both sexes, of which 34 studies performed sex-specific analyses (13.8%). In addition, 27 studies did not specify the sex of all or the majority of the participants (11.0%). Furthermore, looking at the distribution, 10,394 male participants (66.5%) were investigated compared to 3,555 female participants (22.7%). In 1,683 participants (10.8%), no further detail about the sexes were provided. Most studies (n = 113) did not specify climbing disciplines. Figure 2 shows the distribution of included sexes for each climbing discipline.

The 34 studies including sex-specific analyses were categorized into a total of ten categories based on the assessed performance-related and determining factors. As some studies addressed more than one factor, they were assigned to multiple categories. The categories included energetically determined factors (n = 8), flexibility (n = 3), cognitive function, and psychological abilities (n = 3), coordination, skills, and technique (n = 2), nutrition and energy availability (n = 8), anthropometry (n = 5), competition analysis (n = 6), training and adaptations (n = 2), and injuries and mental health (n = 2). Studies examining sex differences across various factors in elite national youth athletes (n = 5) were analyzed in a separate category. A summary of all studies included in the sex-specific analysis can be found in Supplementary Table S2. Overall, the study quality was good with only 28 out of 34 studies having a score >70% which is rated as high quality. Initial discrepancies between raters ranged from 13.2% to 26.2%. All disagreements were resolved during the consensus meeting. A summary of the study quality assessment can be found in Supplementary Table S3.

Overall, our findings show that climbing remains generally under-researched, especially at the high-performance level. We found only 246 studies, which examined elite or advanced climbers [defined according to Draper et al. (30) as having an IRCRA level of 15 or higher for females and 18 or higher for males]. In addition, most studies failed to specify the climbing discipline, which limits the contextual interpretation of research findings.

When examining the sex-comparison, the majority of high-performance climbing studies focus exclusively on male climbers, while research dedicated solely to female athletes remains scarce with a ratio of 41.5% (male) to just 3.3% (female). In absolute numbers, 102 studies were conducted exclusively with male climbers, whereas only 8 studies focused solely on female climbers. Additionally, 27 studies did not specify the sex of their participants and 109 studies included both sexes. Interestingly, however, even in mixed-sex studies, the proportion of male climbers was very high (70%). One fifth of the studies included fewer than 20% female athletes, with many including only one or two female participants. Moreover, only 34 (31.2% of all studies including both sexes) performed sex-specific analyses. However, such analyses are crucial not only to identifying sex-specific differences but also for preventing biased conclusions and for developing evidence-based recommendations that are effective for both sexes, especially for female athletes, who remain underrepresented. Therefore, to gain a clearer picture of this sex data gap, we also examined the overall number of participants across all studies with the result of an evident male bias: 66.5% of participants were male, compared to only 22.7% female, while the sex of 10.8% of the participants was not reported. However, it is reasonable to assume that these were also male participants, given the historical standard of participants being male. If we assume the unknown participants were female, the representation of female athletes would still only reach 33.5%. Overall, these findings are in line with previous literature addressing the sex data gap in different areas of sport and exercise science. For example, in their review Costello et al. (16) demonstrate that female participants are in general underrepresented in sport and exercise science. They analyzed the sex distribution of participants in three leading sport and exercise science journals between 2011 and 2013 and found that females comprised only 39% of total participants. Building on this, Cowley et al. (17) updated these findings, reporting that females accounted for only 34% of total participants and just 6% of total publications between 2014 and 2020 in six leading sport exercise science journals. A recent review in climbing (26) showed similar findings than Costello et al. (16) and Cowley et al. (17). They investigated female representation in rock climbing irrespective of performance level and found a participation rate of 35% females in their reviewed studies. In contrast, we observed a much lower participation rate of females (22.7%), which could be explained by our focus on advanced to higher-elite athletes. Therefore, the imbalance regarding the sex of participants appears to be even more pronounced among advanced to higher-elite athletes. In addition to that, Lee et al. (26) excluded studies that did not report participant sex. Even when recalculating according to their criteria, female representation in our dataset remained low at 25%. Regarding study types, we observed a higher prevalence of male-only studies (41.5%) compared to female-only studies (3.3%). When excluding studies with unreported sex, the prevalence of male-only studies increased to 46.6%, while female-only studies accounted for only 3.7%. This may be because female climbers are particularly well represented at lower to intermediate levels, which could be due to the fact that females have only recently begun participating in the sport in greater numbers (66, 67). Additionally, advanced to higher-elite athletes constitute a highly selective group. Therefore, especially in female athletes, studies often remain underpowered (68), which, according to Burden et al. (68), may lead to fewer studies involving female participants being published.

Furthermore, interestingly, the proportional distribution of studies including female participants in climbing is lower than in the studies of Costello et al. (16) or Cowley et al. (17), with only 22.7% female participants in climbing research compared to 34% and 39% in general exercise science research. This becomes especially relevant considering that with 69% the majority of studies in the field of high-performance climbing have been published after the year 2014. At this time, the sex data gap was already well-known and documented in the scientific community for example by Costello et al. (16). In addition, according to the Olympic charter (in 2013), one responsibility of the international Olympic committee is “to encourage and support the promotion of women in sport at all levels and in all structures, with a view to implementing the principle of equality of men and women” (69). This raises the question of why such a strong male bias still persists in elite climbing research, despite supposedly comparable structural conditions for males and females in sport (69).

One possible explanation could be a systemic and methodological bias in research, shaped by historical trajectories. Traditionally, it was assumed that physiological responses on exercise did not significantly differ between male and female athletes. As a result, male participants were (incorrectly) considered as “standard”. They were therefore predominantly chosen as study participants and findings were generalized to female athletes (17). However, “women are not simply small men” (70) and differ physiologically and anatomically from males, which is why research results based on male participants cannot be directly transferred to female athletes.

A second possible explanation is introduced by Paul et al. (18). The authors examined the sex distribution across various sports such as soccer, basketball, rugby, or baseball/softball, conforming a clear under-representation of female athletes. They argued that elite sports are often male dominated, which has resulted in males being predominantly studied in this field as well. Furthermore, financial considerations and the generally financial support for female sports have been argued as another factor. When applying these arguments to climbing and to our findings these explanations may, however, not be applicable. As noted earlier, climbing is a relatively young sport, introduced to the Olympic program only in 2016. It therefore seems unlikely that male-dominated structures have influenced elite climbing to a degree sufficient to account for the observed imbalance in research. Nevertheless, even though the number of females in climbing has been increasing (66, 67), a male dominance still exists in sub-elite climbing (71, 72), which may have a similar effect on climbing research.

Another commonly discussed reason for the under-representation of female participants in sport and exercise science literature is the composition of the research team (73). Specifically, studies with predominantly male first-authorship tend to include much less female participants. Therefore, we performed a post-hoc analysis examining the probability of including female participants based on the gender of the first author and the year of publication (Supplementary Figure S1). Our findings revealed that when a female researcher is listed as the first author, the likelihood of including female participants increases by a factor of 3.7. This is consistent with the findings of Lee et al. (26), who reported that studies with female first authors had significantly higher proportions of female participants than those with male first authors. Moreover, regardless of the corresponding author's gender, the likelihood of including female participants has increased over time by approximately 4.2% per year.

Finally, the under-representation of females in climbing becomes even more dramatic when comparing the performance of male and female athletes. Compared to other sports such as the 100 m dash, the performance gap between males and females in climbing is remarkably small. According to World Athletics (74), the fastest woman since 1,900 is slower than the 8,139 fastest men in the 100 m dash, highlighting a large sex-based difference in sprint performance. In these kinds of sports, the mechanisms underlying performance differences are based on sex hormones (e. g. testosterone) as well as anatomical differences such as muscle mass or muscle cross-sectional area (20). In contrast, climbing shows much smaller disparities. Although speed climbing, which most closely resembles the demands of sprinting, still exhibits considerable sex differences (75), the gap narrows substantially in lead climbing and bouldering. According to athletes' reports, the hardest route climbed by males is graded 9c on the french sport scale (achieved by three climbers), while the hardest route climbed by a female is only one grade lower (9b+). These smaller performance differences between the sexes compared to many other sports, sex-specific analysis may provide insights into how technique, tactics, and strength are equally important, rather than muscle mass alone.

Climbing performance has been proven to be influenced by a broad spectrum of interrelated performance-determining and performance-relevant factors (3, 5, 6, 10, 23, 24). In this review, 34 studies included sex-specific analyses of various factors. While many studies analyzed sex-specific differences regarding anthropometry, strength, endurance, speed, flexibility, and nutrition and energy availability, research remains limited regarding sex-specific differences related to coordination, skills, and technique, injuries and mental health, cognitive function and psychological abilities, and training and adaptations.

Our findings emphasize that the performance of male and female climbers in different disciplines depends on different factors to varying degrees. While female lead climbing performance was found to be particularly influenced by upper-limb strength and power, as well as finger-flexor muscular endurance, male lead climbing performance, on the other hand, appeared to depend primarily on upper- and lower-limb power, upper-limb strength and endurance, as well as coordination. Furthermore, our results suggest that lower-level male lead climbing performance is additionally influenced by hip, lower-back, and hamstring flexibility, whereas at the elite level, hip-flexibility seems to be especially relevant for female bouldering performance. In addition, both male and female bouldering performance were found to depend on upper-limb strength and power, as well as finger-flexor muscular endurance, whereas male bouldering performance was additionally influenced by coordination. In speed climbing, performance in both sexes was primarily determined by lower- and upper-limb power, as well as upper-limb maximum strength. In males, performance was additionally influenced by upper-limb muscular endurance, whereas in females, it was further explained by finger strength and coordination. In addition to differing factor weightings between male and female athletes across disciplines, these findings show that especially male lead climbing performance seems to depend on a broader spectrum of factors than female performance. This is supported by findings from MacKenzie et al. (37), who reported that 23 out of 47 tested variables were found to correlate with climbing performance in males, whereas in females only 10 out of 47 variables showed significant correlations.

While both male and female climbing performance was found to benefit from a large arm span or ape index, multiple studies have shown that male climbers are, on average, taller and heavier than female climbers. This aligns with the findings of Hunter and Senefeld (20), who reported that, in general, males have longer and denser bones, as well as larger muscle cross-sectional areas, contributing to their greater height and body mass. Additionally, males have been proven to have larger, faster, and stronger muscles (20). Furthermore, the findings are consistent with general sex differences indicating that females tend to be more flexible than males, due to lower tendon stiffness (76, 77) and smaller muscle volume (20) in females. Nonetheless, while female climbers have been found to have a higher body fat percentage, a trend also observed in the general population (20), this difference was found to decrease with increasing performance levels. This is, no surprise in a sport that relies on a high strength-to-mass ratio (21). Nevertheless, it shows that especially female elite athletes show extremely low body fat percentages.

These findings are consistent with research on energy availability in climbing. While some studies reported that participants' total energy intake met target values, others found insufficient carbohydrate intake in both sexes and inadequate protein intake in females. Moreover, it should be noted that females, possibly due to menstrual cycle-related factors (78), have lower blood iron levels which can also impact performance (79). Supplementation did not vary between sexes, however, the reason for supplementation tended to differ with males supplementing more often for increasing muscle mass and performance (51). It is notable, that climbers of both sexes rarely relied on climbing-specific supplements and that only a low portion of climbers had access to nutritional support. These findings emphasize the potential risk of LEA and RED-S in climbing and align with the findings of Tan and Schöffl (80).

Other performance-related factors in sports climbing include cognitive and psychological variables, which are rarely examined in elite female climbers. Our findings show that only three studies met our inclusion criteria in this field. The findings suggest that psychological and cognitive factors are not determined by sex but are more likely influenced by individual differences such as training experiences or personal trait factors. However, it must be mentioned, that the distribution of participants also revealed a clear sex-imbalance, which may have influenced the results. For example, in the study by Garrido-Palomnino et al. (43), only 10 female climbers compared to 25 male climbers were examined. Therefore, these findings must be interpreted with caution. Furthermore, our findings align with those of a recent review by Mangan et al. (81), which investigated psychological factors in rock climbers. They also reported an underrepresentation of female participants and a lack of sex-specific analyses, which limited the interpretability of the results.

Another potential factor that could explain our findings is the difference in route setting between male and female competitors. As our findings show, there are differences between the competition boulders for males and females. While these differences could explain physiological differences between male and female climbers, they may also account for the reported sex-specific injury-patterns (59). Therefore, our results clearly show that differences between male and female climbers should also be considered in injury prevention. While a recent review on injuries and injury prevention in climbing (5) provided general training recommendations for injury prevention, it did not include any sex-specific guidance. Our findings, however, indicate that both climbing performance and injury prevention, given the differing injury patterns, may benefit from sex-specific and discipline-oriented training approaches. Considering the identified performance-determining factors, current research findings point towards incorporating various elements into climbing training. This is especially due to the fact that while research on sex differences in resistance training has shown that males and females adapt similarly to hypertrophy training (82), females were observed to demonstrate greater effect sizes in upper-body strength than males (82), which points towards potential sex-related differences in the outcomes of climbing-specific strength training.

Taken together, the findings of this review highlight that sex-specific differences exist across all performance-determining and performance-relevant factors in climbing. While several determinants overlap between male and female athletes, their relative weighting differs between sexes and climbing disciplines. Although we addressed these factors individually, it must be emphasized that sport performance results from a complex interplay of multiple interacting factors (85). This underscores the importance of considering athletes as multifaceted individuals rather than isolating single determinants. However, research on sex-specific differences in climbing remains limited, and the interactions between factors such as strength, endurance, coordination, flexibility, psychological characteristics, and nutritional status are still insufficiently investigated.