Correlation Between Lower Extremity Length, and Speed, Agility, and Muscle Strength in Athletes According to Sex
Article information
Abstract
PURPOSE
To analyze the correlation between leg length (femur, tibia, and total leg length) and key physical fitness components (muscular strength, muscular endurance, power, agility, flexibility, cardiorespiratory endurance, and anaerobic power) in elite male and female athletes across various sports disciplines.
METHODS
Data from 273 athletes (168 male, 105 female), who underwent anthropometric and physical fitness assessments, were analyzed. Both absolute and relative leg lengths (standardized to height) were examined.
RESULTS
Longer tibial length combined with shorter femoral length was associated with greater agility in male athletes. In contrast, female athletes with longer total leg length exhibited higher anaerobic power. Female athletes with shorter tibial length and longer femoral length exhibited better muscular endurance. Power was positively correlated with leg length among male athletes. However, there was no significant correlation between leg length and cardiorespiratory endurance in either sex.
CONCLUSIONS
Findings suggested that advantageous segmental proportions in the lower limbs may vary according to sex and may be associated with specific components of physical performance. These results may serve to inform the development of preliminary guidelines for athlete selection, evaluation of sports-specific suitability, training programs, and injury prevention strategies.
INTRODUCTION
Humans continue to evolve physiologically, and this ongoing evolution is particularly evident in various sports disciplines. Athletes often reflect both genetic and environmental influences through their choice of sports [1]. Consequently, in addition to physiological attributes, numerous anthropometric and body composition variables may contribute to athletic performance and outcomes. Examples include body fat and lean body mass [2], arm circumference [3], and skinfold thickness [4,5], all of which have been found to be closely associated with athletic performance. In particular, leg length directly affects gait and stride length [6], making it a critical variable in many ground-based sports.
Recent studies have reported that not only the absolute length of the upper (femur) and lower (tibia) legs but also their relative length normalized by height are positively correlated with running performance [7]. Bchini et al. [8] reported that leg length, along with muscle volume, is significantly related to jump performance in adolescent athletes; however, the potential effects of sex differences and sport-specific characteristics have not been fully addressed. According to Hallam and Amorim (2022) [9], anthropometric characteristics including lower limb length contribute to observed sex differences in running performance, suggesting that segmental proportions may play a key role in explaining performance variability between male and female athletes. Longer legs may enable more efficient movement and reduced energy expenditure, providing an advantage in endurance sports [10–12]. Additionally, extended leg length can increase stride length and improve sprint performance [13,14].
However, findings are not always consistent. For instance, Bakti et al. [15] reported a negative correlation (r=–0.369) between leg length and leg explosive power, suggesting that shorter legs may produce greater power. Contrarily, a study by Nasrulloh et al. [16] on volleyball players found that athletes with longer legs exhibited significantly greater lower-limb strength and power. Furthermore, our recent research reported positive correlations between leg length and various performance variables— such as agility, anaerobic peak power, and cardiorespiratory endurance— across athletes in different disciplines [17], highlighting the complex interplay between sport-specific demands and anthropometric factors.
Previous literature has also noted sex-based differences in leg length, with male athletes generally exhibiting longer femur and tibia lengths than females [18]. Bchini et al. [19] analyzed lower limb length, muscle mass, and jumping ability in adolescents aged 16–19, finding that males had legs approximately 6.2% longer than females, along with higher muscle power. Additionally, Gill et al. [20] suggested that transition speed may differ by sex depending on lower limb length.
Traditionally, leg length has been measured using simple tools such as tape measures, which are limited in terms of accuracy and reproducibility. Recently, dual-energy X-ray absorptiometry (DEXA) [21] and magnetic resonance imaging (MRI) [22] have been employed for more precise measurements of the femur and tibia. While these methods offer high reliability, their cost and accessibility pose practical limitations for broad application in sports science. Therefore, anthropometric instruments such as the Martin anthropometer, operated by trained professionals, may provide a more practical and reliable alternative for measuring leg segment lengths.
In summary, existing research suggests that lower limb length— including both femur and tibia— is closely associated with various performance attributes such as endurance, sprinting ability, and jumping power [15,23]. However, prior studies have often focused on single-sport athletes with small sample sizes, and there remains a lack of research analyzing the segmented leg length in relation to comprehensive physical fitness indicators, particularly with respect to sex-based differences. Most previous studies examined single-sport athletes with limited sample sizes, and few have analyzed segmental leg length in relation to comprehensive fitness indicators, particularly with sex-based comparisons. Given that advantageous anthropometric proportions may differ by sex and sport, further refined analyses across diverse athlete populations are necessary.
This study aims to assess the relationship between leg length (absolute and relative) and fitness parameters among male and female athletes from various sports. The findings may aid in talent identification, sport selection, and the design of sport-specific training programs. Furthermore, the results may contribute to injury prevention strategies by identifying risk factors associated with anthropometric characteristics.
METHODS
1. Participants
This study was conducted at the Center for Sport Science in Incheon. A total of 273 elite athletes (168 males and 105 females) were recruited for the study. Participants were selected from the following sports: Judo (n=13), tennis (n=8), wrestling (n=9), archery (n=4), weightlifting (n=1), baseball (n=28), shooting (n=3), fencing (n=6), seppak takraw (n=5), running sprinter (n=9), Taekwondo (n=12), badminton (n=6), field hockey (n=11), fin swimming (n=8), soccer (n=22), swimming (n=16), team handball (n=80), boxing (n=7), cycling (n=12), modern pentathlon (n=5), and rowing (n=9). Athletes with a history of cardiac, pulmonary, or inflammatory diseases or other medical contraindications were excluded from the study. All participants who agreed to participate were provided with a detailed description of the study, including its purpose and the methods used, in accordance with the ethical standards outlined in the Declaration of Helsinki. Additionally, all participants signed an informed consent form prior to participation. This study was approved by the University's Institutional Review Board for Human Subjects (1041459-202411-HR-008-01).
2. Experimental procedures
The participants (athletes) visited the laboratory as teams based on their respective sports disciplines. During their visit, anthropometric measurements, including lower limb length (tibia length and femur length) and body composition assessments (height, weight, body fat mass, etc.) were conducted. After a sufficient warm-up, tests for basic physical performance (muscular strength, muscular endurance, muscular power, cardiorespiratory endurance, agility, and flexibility) and anaerobic power (peak power) were performed. The participant information is presented in Table1.
The characteristic of the subjects
3. Body composition and anthropometric measurements (Femur and tibia length)
Leg length measurements were conducted by trained professionals using a sliding caliper (Martin's Anthropometer, Japan), as shown in Figure 1. The femoral length was measured as the distance between the tip of the greater trochanter and the distal end of the lateral condyle of the femur. The tibial length was measured as the distance between the proximal end of the lateral condyle and the distal inferior surface of the tibia (lateral malleolus). Anthropometric measurements included body weight (BW), body mass index (BMI), and body fat percentage (%FAT); these measurements were obtained using the body composition analyzer InBody 770 (InBody Co., Seoul, Republic of Korea) using the simultaneous multi-frequencies impedance measurement method. To increase measurement accuracy, alcohol consumption and strenuous exercises on the day before the measurement and any form of drinking or eating 2 h before the measurement was prohibited.
The measurement position of upper leg length and lower leg length.
4. Basic physical performance assessments
The athletes underwent basic physical performance assessments (muscular strength, muscular endurance, muscular power, cardiorespiratory endurance, agility, and flexibility) using sensor-based equipment. To evaluate leg power, the standing long jump and Sargent jump tests [24] were conducted. Lower body agility was assessed using the 10 m shuttle run and side-step test [25, 26]. Cardiovascular endurance was measured with the shuttle run test [27], while flexibility was evaluated using the sit-and-reach test [28]. Grip strength was used to assess muscular strength [29].
5. Anaerobic test
The Wingate anaerobic test (WAnT) was used following experiments performed by Castañeda-Babarro [30]. The WAnT was performed on a cycle ergometer (Monark 824 E, Monark, Sweden) equipped with a photoelectric sensor for recording 1.0 kg resistance baskets and flywheel revolutions. Data for each 30 s WAnT were collected using POWER soft-ware (SMI, St Cloud, MN, USA) and an IBM-compatible microcomputer. Each participant completed a self-selected stretching exercise and a five-minute cycle at the ergometer without applying a time limit. At the end of the 1 min warm-up, each participant performed an “ all-out” sprint for 4 to 5 s to simulate the actual test. Before starting the WAnT, the resistance for each participant was calculated using a body weight of kilograms multiplied by 7.5% for males and 5% for females, and the determined amount was placed in the basket. At the start of the test, the assistant lifted the resistance basket, and no resistance was applied to the flywheel; each participant was instructed to begin pedaling to reach the maximum rpm at the end of the 5 s countdown. The resistance basket was released, and data collection began, subsequently ending after 30 s. Among the test results, we analyzed peak power data in relation to leg length.
6. Statistical analysis
All values are presented as means with standard deviations. GraphPad Prism 10.0 (GraphPad Software Inc., CA, USA) was used for the statistical evaluation and preparation of graphs. Data analysis was conducted with the Statistical Package for the Social Sciences, version 23.0 (IBM SPSS Statistics for Windows, Version 23.0: IBM Corp., Armonk, NY, USA). The relationships among variables (leg length × physical performance) were analyzed using Pearson's correlation coefficients. Leg length by sex was verified through Independent Samples t testing, including normality and homoscedasticity. Normality of the data was assessed using the Shapiro-Wilk test, and homoscedasticity of variances was evaluated using Levene's test. Statistical significance was accepted at the 0.05 level.
RESULTS
The analysis revealed that male athletes had significantly greater absolute leg length (p <.001) and relatively longer leg length when adjusted for height (p <.05) than female athletes (Table 2).
Differences in leg length according to sex
Correlation analyses showed that in the overall group, longer leg length was significantly associated with better performance in several physical fitness variables, including standing long jump (SLJ), squat jump (SJ), 10-meter run time (10mRT), sit-and-reach flexibility (SR), grip strength (GS), and peak power (PP), with correlation coefficients ranging from r=–0.190 to r=0.593 (p <.001).
In females, muscular endurance was positively correlated with longer femur length (r=0.242, p =.014) and negatively correlated with tibia length (r=–0.188, p =.004). Among males, explosive power showed positive correlations with both tibia (r=0.187, p =.015) and femur lengths (r=0.167, p =.030). For agility, male athletes with longer tibias (r=–.308, p <.001) and shorter femurs (r=0.195, p =.022) performed better. In terms of muscular strength, tibia length (r=0.211, p =.006) and total leg length (r=0.218, p <.005) were positively correlated with performance in males. Notably, only female athletes showed a significant positive correlation between total leg length and anaerobic peak power (r=0.218, p =.025). No significant correlations were found between leg length and cardiorespiratory endurance across all groups (Table 3, Figure 2).
Correlations coefficients between leg length and fitness Fitness performance
Relationships between the relative leg lengths and fitness performance. (A) Tibia length; (B) Femur length; (C) Tibia+Femur length.
DISCUSSION
The primary aim of this study was to investigate the relationships between anthropometrically measured leg lengths (tibia, femur, and combined length) and various physical fitness components among elite athletes, while accounting for sex-based differences.
The results demonstrated significant correlations between absolute leg length and physical fitness variables— including strength, muscular endurance, agility, flexibility, explosive power, and anaerobic peak power— across all participants (r=–0.190 to .593, p <.001). Sex-specific analysis showed that in female athletes, shorter tibia and longer femur lengths were associated with greater muscular endurance. In contrast, for males, longer tibia and femur lengths correlated with greater explosive power, while agility was favored by longer tibias and shorter femurs. No statistically significant relationship was found between leg length and cardiorespiratory endurance.
These findings offer further support for the idea that leg length is closely associated with multiple performance indicators in elite athletes. They also highlight the existence of relative advantages and disadvantages in physical fitness depending on leg segment proportions and sex.
Although prior studies have examined anthropometric variables in athletes [31,32], few have specifically focused on the relationships between limb segment ratios and performance outcomes [7,19,33]. Furthermore, sex-based differences in body dimensions and performance factors must be considered [34].
Strength, endurance, agility, and explosive power are essential components of athletic performance and play a critical role not only in competition but also in reducing injury risk [35,36]. Agility, in particular— the ability to quickly change direction while maintaining balance— is a fundamental skill in many sports [37].
From a biomechanical standpoint, the ratio of tibia to femur length may enhance movement efficiency by reducing lower limb moment of inertia and improving hip flexor action [38]. This structural advantage may support better sprint performance in sports requiring rapid, forceful movements.
Muscle development in the thigh region— including quadriceps and hamstrings— has been associated with improved sprint performance [2, 4, 10]. Sex differences observed in this study may be attributed to such structural and muscular factors.
Sex hormones, particularly testosterone, peak during adolescence (16–19 years), significantly influencing muscle development [39]. Testoster-one promotes muscle protein synthesis, which could explain the sex-based differences in muscle power and limb length observed in this study [40]. Given that the average age of participants was 18.46 years, hormonal differences may have influenced anthropometric outcomes and performance.
Interestingly, this study did not find significant associations between leg length and cardiorespiratory endurance. This contrasts with prior research on East African long-distance runners [7], who often exhibit long tibias and high endurance. Morrison & Dick [41] suggested that longer tibias may be associated with longer Achilles tendons, improving running performance. However, the lack of correlation in this study may stem from the sports disciplines included— such as shooting, archery, weightlifting, swimming, and baseball— which do not rely heavily on continuous running. In this study, the absence of a significant correlation between leg length and cardiorespiratory endurance can be interpreted as being influenced by the characteristics of the included sports. In particular, the relatively high proportion of non-running sports (e.g., baseball, fencing, archery, judo, wrestling) among the participants may have reduced the direct impact of leg length on cardiorespiratory endurance. In this context, cardiorespiratory endurance tends to be more closely related to leg length in endurance-oriented, running-based sports, whereas in non-running sports that emphasize technical skills or explosive power, factors such as muscular endurance, coordination, and technical proficiency play a more decisive role than leg length.
Therefore, sport-specific classifications should be considered in future studies to avoid confounding effects and ensure accurate interpretation of results.
Apart from structural traits, the combination of speed, strength, endurance, agility, and flexibility also contributes to overall athletic performance. These capabilities are influenced by an individual's physiological characteristics, highlighting the need for physical fitness development as a key component of athletic training [42].
The findings of this study can serve as a reference for athlete selection and the design of training programs. For instance, considering the relationships between leg length and physical fitness components, relatively longer tibias may be advantageous for sports emphasizing agility and explosiveness, such as soccer, handball, and badminton, whereas a balanced proportion of femur and tibia may be more relevant for sports that prioritize strength and power, such as wrestling, judo, and boxing. However, as this study was an observational analysis encompassing athletes from various disciplines, it is limited in providing exact optimal ratios for specific sports. Therefore, practical application should take into account sport-specific characteristics, training goals, and individual anthropometric differences. Within this context, the present findings offer a practical implication as a preliminary guideline for evaluating athlete characteristics and developing tailored training programs. It should be noted that the observed associations between lower limb segmental proportions and physical performance are correlational. While these findings may offer preliminary insights for athlete selection and training program considerations, they do not establish causal relationships. Consequently, any practical applications should be regarded as reference points rather than definitive guidelines, and further longitudinal or experimental studies are required to validate direct effects.
Future research should systematically analyze the relationship between leg length (e.g., femur and tibia) and fitness attributes such as explosive power and agility across different sports and sexes. Incorporating biomechanical and physiological parameters may further clarify these relationships, offering valuable insights for performance enhancement and sports science.
CONCLUSION
In conclusion, this study confirmed significant associations between absolute leg length and various physical fitness components in elite athletes. Importantly, relative leg length (tibia, femur, and combined) was shown to have differing relationships with fitness parameters depending on sex.
Among male athletes, longer tibia and shorter femur lengths were associated with enhanced agility, suggesting that segmental leg proportions may influence specific performance traits. In female athletes, longer total leg length was positively associated with greater anaerobic muscle power.
No significant correlation was found between leg length and cardiorespiratory endurance, which may be attributable to the nature of the sports represented in the sample. The findings provide valuable data for talent identification, athlete placement, sport selection, and performance prediction. Future research should include a larger and more diverse sample to allow more refined and generalizable conclusions.