Sex differences in human performance
人类表现的性别差异

Sex 性别

‘Sex’ is sometimes erroneously used interchangeably with ‘gender’, but these terms describe two different and interrelated concepts (Stefanick & Schiebinger, 2020). Sex refers to an amalgam of biological attributes, including chromosomes, genes, hormone concentrations, gamete size and reproductive anatomy (National Academies of Sciences & Medicine, 2022; National Institutes of Health, 2024; Short et al., 2013). Every human, every animal, every tissue and every cell has a sex (Miller, 2012). Sex is determined by the presence of XX (female) or XY (male) chromosomal complements (Miller, 2012). While sex is dichotomized as male or female, there are other less common variations of sex chromosomes considered disorders of sexual development (DSD) or intersex conditions (Grimstad et al., 2021). Because there is limited research on human performance in people with DSD and intersex conditions (Nokoff et al., 2023), this review focuses on assessing differences between males and females. Better understanding the impact of DSD and intersex conditions on human performance presents an opportunity for future investigations.
“性别”有时会被错误地与“性别”互换使用，但这些术语描述了两个不同且相互关联的概念（Stefanick & Schiebinger， 2020 ）。性别是指生物属性的混合体，包括染色体、基因、激素浓度、配子大小和生殖解剖学（美国国家科学院和医学院， 2022 ；美国国立卫生研究院， 2024 ；Short 等， 2013 ）。每个人、每个动物、每个组织和每个细胞都有性别（Miller， 2012 ）。性别由 XX（女性）或 XY（男性）染色体互补体的存在决定（Miller， 2012 ）。虽然性别分为男性或女性，但性染色体还有其他不太常见的变异，被认为是性发育障碍 (DSD) 或双性病症 (Grimstad et al., 2021 )。由于对 DSD 和双性人的人类表现的研究有限（Nokoff 等人， 2023 ），本综述侧重于评估男性和女性之间的差异。更好地了解 DSD 和双性条件对人类表现的影响为未来的研究提供了机会。

The Y chromosome is among the smallest human chromosomes and associated with less than 50 protein-coding genes (Rhie et al., 2023). Among these genes, expression of the sex-determining region Y (SRY) gene induces testis, male testosterone production and male puberty, and represents the primary, deterministic gene contributing to robust and large sex differences in physiology, anatomy and human performance, most notably in events and tasks involving muscle power, strength, speed and aerobic endurance (Handelsman et al., 2018). Confirmatory evidence of the importance of the SRY gene may be observed in the phenotype of 46, XX humans who are SRY-positive due to SRY translocation onto one or both X chromosomes and inevitably develop a male phenotype with elevated endogenous testosterone and often both male internal and external genitalia (Délot & Vilain, 1993). Notably, there was a previous theory that uncharacterized gene(s) on the Y chromosome contribute to sex differences in human development (Ferguson-Smith & Bavington, 2014), but this theory has been discredited (Handelsman, 2024; Handelsman et al., 2018).
Y 染色体是最小的人类染色体之一，与不到 50 个蛋白质编码基因相关（Rhie 等人， 2023 ）。在这些基因中，性别决定区 Y (SRY) 基因的表达可诱导睾丸、男性睾酮生成和男性青春期，并且是导致生理学、解剖学和人类表现方面强烈和巨大性别差异的主要决定性基因，最显着的是在涉及肌肉力量、力量、速度和有氧耐力的事件和任务中（Handelsman et al., 2018 ）。 SRY 基因重要性的确凿证据可以在 46, XX 人的表型中观察到，这些人由于 SRY 易位到一条或两条 X 染色体上而呈 SRY 阳性，并且不可避免地会形成内源性睾酮升高的男性表型，并且通常都是男性内源性睾酮。和外生殖器（Délot & Vilain， 1993 ）。值得注意的是，之前有一种理论认为 Y 染色体上的未表征基因会导致人类发育中的性别差异（Ferguson-Smith & Bavington， 2014 ），但该理论已被质疑（Handelsman， 2024 ；Handelsman 等人， 2018 ）。

Gender 性别

Gender is a multidimensional construct that encompasses gender identity and expression, and a constellation of social and cultural expectations (Reale et al., 2023; Short et al., 2013). A person's gender is self-identified, may change throughout their life, and may or may not correspond to society's cultural expectations based on their biological sex traits (Reale et al., 2023; Short et al., 2013). Research to understand the impact of gender on human performance is more limited and reviewed elsewhere (Gooren & Bunck, 2004; Harper et al., 2021; Nokoff et al., 2023; Roberts et al., 2021) with recent data indicating that the ‘sex’ of an athlete is more predictive of running performances than ‘gender’ (Armstrong et al., 2023). While gender is less amenable to investigation in preclinical models (Clayton, 2016), the impact of gender on human health and performance is understudied with many opportunities for future studies (Nokoff et al., 2023). This review, however, focuses on sex-based differences in human performance.
性别是一个多维结构，包含性别认同和表达，以及一系列社会和文化期望（Reale et al., 2023 ；Short et al., 2013 ）。一个人的性别是自我认定的，可能会在一生中发生变化，并且可能符合也可能不符合基于其生物性别特征的社会文化期望（Reale等人， 2023 ；Short等人， 2013 ）。了解性别对人类表现影响的研究更加有限，并在其他地方进行了审查（Gooren & Bunck， 2004 ；Harper 等人， 2021 ；Nokoff 等人， 2023 ；Roberts 等人， 2021 ），最近的数据表明，运动员的“性别”比“性别”更能预测跑步表现（Armstrong 等人， 2023 ）。虽然性别不太适合在临床前模型中进行调查（Clayton， 2016 ），但性别对人类健康和表现的影响尚未得到充分研究，未来有很多研究机会（Nokoff 等， 2023 ）。然而，这篇评论的重点是人类表现中基于性别的差异。

Testosterone 睾酮

Testosterone is the primary sex hormone and anabolic steroid in males, and a key determinant of sex differences in human motor performance from puberty into adulthood. Demonstrative evidence supports the performance-enhancing effects associated with testosterone (and other anabolic androgenic steroids) (Franke & Berendonk, 1997; Handelsman et al., 2018; Saudan et al., 2006; Wood & Stanton, 2012) and provides a clear scientific rationale for including testosterone as a banned substance in competitive sports since the 1970s for both males and females (Saudan et al., 2006; Wood & Stanton, 2012). In this framework, higher concentrations of endogenous testosterone among postpubescent males (15 times higher than females of any age) and the physiological and anatomical consequences of chronic exposure, lead to an athletic advantage among males compared with females (Handelsman, 2017; Hunter et al., 2023; Senefeld et al., 2019, 2020).
睾酮是男性的主要性激素和合成代谢类固醇，也是从青春期到成年期人类运动表现性别差异的关键决定因素。证据支持与睾酮（和其他合成代谢雄激素类固醇）相关的性能增强作用（Franke & Berendonk， 1997 ；Handelsman 等， 2018 ；Saudan 等， 2006 ；Wood & Stanton， 2012 ），并提供了明确的科学依据自 20 世纪 70 年代以来，将睾酮列为竞技体育中男性和女性禁用物质的理由（Saudan 等人， 2006 年；Wood 和 Stanton， 2012 年）。在这个框架中，青春期后男性的内源性睾酮浓度较高（比任何年龄的女性高 15 倍）以及长期暴露的生理和解剖学后果，导致男性与女性相比具有运动优势（Handelsman， 2017 ；Hunter 等人） .， 2023 ；Senefeld 等人， 2019、2020 ）。

Testosterone and its more potent metabolite dihydrotestosterone (DHT) contribute to the development and maintenance of androgen-dependent characteristics. Androgens are common therapeutics used to regulate skeletal muscle mass (Alemany, 2022), and synthetic anabolic androgenic steroids promote augmented skeletal muscle mass and performance in both males and females (Bhasin et al., 2021; Franke & Berendonk, 1997; Hirschberg et al., 2020). In this context, it is well accepted that exogenous testosterone will likely induce performance-enhancing effects (Franke & Berendonk, 1997) and drugs that block the action of endogenous testosterone will impair athletic performance (Harper et al., 2021; Nokoff et al., 2023; Senefeld et al., 2023). However, whether there is a within-sex association between endogenous (non-pharmacologically manipulated) testosterone and athletic performance or key determinants of performance of males and females, remains contentious. The controversy and confusion about the anabolic effects of testosterone arises from several key observations. First, among elite adult athletes, endogenous free testosterone (and not total testosterone) has been associated with athletic performance in only a subset of track and field events (5 of 21 events) among females, but no such relationship was observed for the other events among females or any event among males (Bermon & Garnier, 2017, 2021). Second, transient and modest increases in endogenous testosterone after resistance exercise training are not associated with increases in muscle protein synthesis or hypertrophic adaptations among males or females (Mitchell et al., 2013; Morton et al., 2016; West et al., 2009, 2010, 2012; Wilkinson et al., 2006). As recently and comprehensively reviewed (Roberts et al., 2023), an integrated amalgam of physiological factors is likely required for skeletal muscle adaptations to exercise, and there is no clear reductionist link between transient elevations of endogenous testosterone and skeletal muscle adaptations to exercise training. Third, cross-sectional studies show that among postmenopausal or premenopausal females, endogenous total testosterone, which is low in these populations, is not associated with skeletal muscle mass or strength, with considerably less data available among premenopausal females (Alexander et al., 2021, 2022; Carcaillon et al., 2012; Gower & Nyman, 2000; Pollanen et al., 2011; Rariy et al., 2011; Sipilä et al., 2006; Taylor et al., 2023). Endogenous free testosterone, however, is associated with skeletal muscle mass (e.g. Rariy et al., 2011; van Geel et al., 2009), and this relationship is likely mediated by insulin, oestrogen or sex hormone-binding globulin (Alexander et al., 2022). The evidence base examining this potential association between total or free testosterone with skeletal muscle mass, lean body mass and strength among males is heterogenous – many studies show such a relationship and some studies do not find this relationship (Araujo et al., 2008; Brown, 2008; Ma et al., 2024; Morton et al., 2018; Mouser et al., 2016; van den Beld et al., 2000). These studies in males typically concentrate on older adults who have waning levels of sex-steroid hormones.
睾酮及其更有效的代谢物二氢睾酮 (DHT) 有助于雄激素依赖性特征的发展和维持。雄激素是用于调节骨骼肌质量的常见疗法（Alemany， 2022 ），合成代谢雄激素类固醇可促进男性和女性的骨骼肌质量和性能增强（Bhasin 等， 2021 ；Franke 和 Berendonk， 1997 ；Hirschberg 等） ., 2020 ).在这种情况下，人们普遍认为外源性睾酮可能会产生增强成绩的效果（Franke & Berendonk， 1997 ），而阻断内源性睾酮作用的药物会损害运动表现（Harper 等， 2021 ；Nokoff 等，2021）。 ， 2023 ；塞内菲尔德等人， 2023 ）。然而，内源性（非药物操纵的）睾酮与运动表现或男性和女性表现的关键决定因素之间是否存在性别内关联，仍然存在争议。关于睾酮合成代谢作用的争议和困惑源于几个关键的观察结果。首先，在成年精英运动员中，内源性游离睾酮（而非总睾酮）仅在女性田径比赛的一部分（21 项赛事中的 5 项）中与运动表现相关，但在其他赛事中没有观察到这种关系。女性之间或男性之间的任何事件（Bermon＆Garnier， 2017，2021 ）。 其次，抗阻运动训练后内源性睾酮的短暂和适度增加与男性或女性肌肉蛋白质合成或肥大适应的增加无关（Mitchell 等， 2013 ；Morton 等， 2016 ；West 等， 2009） ，2010 年， 2012 年；威尔金森等人， 2006 年）。正如最近的全面综述（Roberts 等， 2023 ），骨骼肌适应运动可能需要综合生理因素，并且内源性睾酮短暂升高与骨骼肌对运动训练的适应之间不存在明显的还原论联系。第三，横断面研究表明，在绝经后或绝经前女性中，内源性总睾酮在这些人群中较低，与骨骼肌质量或强度无关，绝经前女性中可用的数据要少得多（Alexander et al., 2021） ，2022 ； Gower 和 Nyman， 2000 ；Rariy等，2006 ； Taylor 等， 2023 。然而，内源性游离睾酮与骨骼肌质量相关（例如 Rariy 等人， 2011 年；van Geel 等人，2011 年）。， 2009 ），并且这种关系可能是由胰岛素、雌激素或性激素结合球蛋白介导的（Alexander 等， 2022 ）。检验男性总睾酮或游离睾酮与骨骼肌质量、去脂体重和力量之间潜在关联的证据基础是异质的——许多研究显示了这种关系，而一些研究没有发现这种关系（Araujo 等人， 2008 年；Brown） ， 2008 ；Morton 等人， 2018 ；Mouser 等人， 2016 ；van den Beld 等人， 2000 ）。这些针对男性的研究通常集中于性类固醇激素水平下降的老年人。

Importantly, the interindividual variability in the relationship between testosterone levels and physiological adaptations are influenced by two important confounding factors: (1) the sigmoidal dose–response relationship for testosterone, and (2) androgen receptor content. Elite female athletes (who have lower endogenous testosterone concentrations than males) have greater performance-enhancing effects from exogenous testosterone than elite male athletes (Franke & Berendonk, 1997). These findings suggest that, generally, females represent the low-to-middle region of the sigmoidal dose–response relationship such that relatively small increases in testosterone may have a profound physiological response. In contrast, although males also display a dose–response relationship with exogenous testosterone (Bhasin et al., 2001; Storer et al., 2008), this relationship appears to be blunted compared with that of females. Accordingly, the blunted performance-enhancing effects of exogenous testosterone in males relative to females suggests that males represent an upper plateau of the dose–response relationship. The different androgen-dependent processes in males and females likely have varying testosterone dose–response relationships (Bhasin et al., 2001). Also, there is evidence of sex differences in response to testosterone, particularly in the context of exercise training, such that males and females have different responses in two key factors regulating skeletal muscle hypertrophy – muscle transcriptome (Pataky et al., 2023; Yoshioka et al., 2007) and androgen receptor content (Hatt et al., 2024).
重要的是，睾酮水平和生理适应之间关系的个体差异受到两个重要混杂因素的影响：（1）睾酮的S形剂量反应关系，（2）雄激素受体含量。优秀的女性运动员（其内源性睾酮浓度低于男性）比优秀的男性运动员具有更大的外源性睾酮提高成绩的效果（Franke & Berendonk， 1997 ）。这些发现表明，一般来说，女性代表乙状剂量反应关系的中低区域，因此睾酮相对较小的增加可能会产生深远的生理反应。相比之下，尽管男性也表现出与外源睾酮的剂量反应关系（Bhasin 等， 2001 ；Storer 等， 2008 ），但与女性相比，这种关系似乎较弱。因此，相对于女性，外源性睾酮对男性的性能增强作用减弱，这表明男性代表了剂量反应关系的上部平台。男性和女性不同的雄激素依赖性过程可能具有不同的睾酮剂量反应关系（Bhasin 等， 2001 ）。此外，有证据表明对睾酮的反应存在性别差异，特别是在运动训练的背景下，男性和女性对调节骨骼肌肥大的两个关键因素——肌肉转录组有不同的反应（Pataky 等， 2023 ；Yoshioka 等）等人。， 2007 ）和雄激素受体含量（Hatt 等， 2024 ）。

Additionally, among a group of young healthy males with homogeneously high endogenous testosterone concentrations, there is evidence that muscle androgen receptor content is more closely associated with skeletal muscle hypertrophy after resistance exercise training than hormone concentrations (Morton et al., 2018). Thus, there are conflicting findings in the literature examining the (within-sex) relationship between endogenous testosterone and skeletal muscle mass, as an example, likely due to an amalgamation of factors including: (1) studying a narrow physiological range of testosterone concentrations by examining only one biological sex (males), (2) heterogeneity in dose–response relationships, and (3) heterogeneity in androgen receptor content (Alexander et al., 2021, 2022; Morton et al., 2018; Mouser et al., 2016). Thus, there is substantial between-individual and between-sex variability in the relationship between endogenous testosterone and skeletal muscle mass and strength. There is, however, a clear, direct and causal relationship between pharmacological manipulation of testosterone and both athletic performance and key determinants of performance (such as skeletal muscle morphology and function) among males and females across the lifespan.
此外，在一组内源性睾酮浓度均一的年轻健康男性中，有证据表明，与激素浓度相比，肌肉雄激素受体含量与阻力运动训练后骨骼肌肥大的关系更为密切（Morton et al., 2018 ）。因此，在研究内源性睾酮和骨骼肌质量之间（性别内）关系的文献中存在相互矛盾的发现，例如，可能是由于多种因素的综合作用，包括：（1）通过研究睾酮浓度的狭窄生理范围仅检查一种生物性别（男性），(2) 剂量反应关系的异质性，以及 (3) 雄激素受体含量的异质性（Alexander 等人， 2021、2022 ；Morton 等人， 2018 ；Mouser 等人， 2016 ）。因此，内源性睾酮与骨骼肌质量和强度之间的关系存在显着的个体间和性别间差异。然而，在男性和女性的整个生命周期中，睾酮的药理学操作与运动表现和表现的关键决定因素（例如骨骼肌形态和功能）之间存在明确、直接和因果关系。

The notion that male puberty positively influences skeletal muscle function dates to antiquity, modern knowledge has provided foundational, mechanistic insights into human androgens. The cascade of anabolic effects on skeletal muscle are initiated by androgens (testosterone) binding to androgen receptors localized within the sarcoplasm (Roberts et al., 2023). The androgen receptor then releases chaperone proteins, dimerizes and translocates into the nucleus to bind within the promoter region of the DNA of androgen-sensitive genes, acting as a transcription factor and altering the mRNA expression of thousands of genes (Roberts et al., 2023). Importantly, the human androgen receptor gene contains a polymorphic CAG (glutamine) repeat sequence that has been associated with androgen-related conditions (Giovannucci et al., 1997; Mitsumori et al., 1999), fat-free mass (an estimate of muscle mass) (Walsh et al., 2005) and endogenous testosterone concentrations in some but not all studies among males (Krithivas et al., 1999; Van Pottelbergh et al., 2001), such that longer CAG repeat sequences may be predictive of better outcomes – reduced risk of androgen conditions, more skeletal muscle mass and higher testosterone concentrations. The downstream physiological effects of these changes in gene expression include increases in: (1) skeletal muscle fibre numbers and size (hypertrophy), (2) the number of skeletal muscle satellite cells, (3) myonuclei number, and (4) the size of motor neurons (Herbst & Bhasin, 2004). There is experimental evidence supporting other physiological changes which may enhance energetic and power generation of skeletal muscle including increases in skeletal muscle, mitochondrial biogenesis in male mice (Usui et al., 2014), myoglobin expression in male mice (Mänttäri et al., 2008) and insulin-like growth factor 1 (IGF-1) content among male humans (Ferrando et al., 2002). Although this review often refers to the effects of sex-steroid hormones to be simplistic, there are many contributing factors from epigenetics to small molecules to regulation of larger organ systems such as skeletal and cardiac muscle.
男性青春期对骨骼肌功能产生积极影响的观念可以追溯到古代，现代知识为人类雄激素提供了基础的、机械的见解。对骨骼肌的合成代谢效应级联是由雄激素（睾酮）与肌浆内的雄激素受体结合引发的（Roberts 等人， 2023 ）。然后，雄激素受体释放伴侣蛋白，二聚化并易位到细胞核中，与雄激素敏感基因的 DNA 启动子区域结合，充当转录因子并改变数千个基因的 mRNA 表达（Roberts 等， 2023 ） ）。重要的是，人类雄激素受体基因含有多态性 CAG（谷氨酰胺）重复序列，该序列与雄激素相关病症相关（Giovannucci 等， 1997 ；Mitsumori 等， 1999 ）、去脂质量（肌肉的估计值）质量）（Walsh 等， 2005 ）和一些但不是所有男性研究中的内源性睾酮浓度（Krithivas 等， 1999 ；Van Pottelbergh 等， 2001 ），因此较长的 CAG 重复序列可能更好地预测结果 – 降低雄激素状况的风险、增加骨骼肌质量和提高睾酮浓度。这些基因表达变化的下游生理效应包括增加：(1) 骨骼肌纤维数量和大小（肥大），(2) 骨骼肌卫星细胞数量，(3) 肌核数量，以及 (4) 大小运动神经元（Herbst & Bhasin， 2004 ）。 有实验证据支持其他生理变化可能增强骨骼肌的能量和发电，包括骨骼肌的增加、雄性小鼠的线粒体生物发生（Usui 等人， 2014 ）、雄性小鼠的肌红蛋白表达（Mänttäri 等人， 2008 ） ）和男性人类中胰岛素样生长因子 1 (IGF-1) 含量（Ferrando 等， 2002 ）。尽管这篇评论经常将性类固醇激素的影响过于简单化，但有许多影响因素，从表观遗传学到小分子，再到骨骼和心肌等较大器官系统的调节。

Consequently, the pronounced differences between males and females in endogenous testosterone concentrations beginning at puberty (Handelsman et al., 2018; Senefeld et al., 2020) correspond to sex-specific divergence such that compared with females, males develop greater muscle mass that contracts faster; higher oxygen-carrying capacity in the blood (via haematocrit and haemoglobin); a larger cardiac output; lower percentage body fat, and consequently better sports performance involving strength, speed, power and aerobic endurance (Handelsman et al., 2018; Hilton & Lundberg, 2021; Hunter et al., 2023; Nokoff et al., 2023; Petek et al., 2023; Senefeld et al., 2019). Also, throughout puberty, immutable sex differences in anatomical structure develop, such that, on average, males are taller; have longer limbs; have larger lungs and greater cross-sectional areas of conducting airways; possess more muscle mass, and have larger hearts than females (Dominelli et al., 2019; Hilton & Lundberg, 2021; Hunter et al., 2023). Due to the profound performance-enhancing effects associated with testosterone and related adaptations in physiological and anatomical systems, competitive sports are generally dichotomized between males and females during and after puberty. The divergence in athletic performance between males and females, which is very large at puberty, may also be attributed, in part, to the action of the oestrogens (Khosla et al., 1998; Ober et al., 2008).
因此，从青春期开始，男性和女性之间的内源睾酮浓度存在显着差异（Handelsman et al., 2018 ；Senefeld et al., 2020 ），这与性别特异性差异相对应，因此与女性相比，男性会发展出更大的收缩肌肉质量。快点;血液中更高的携氧能力（通过血细胞比容和血红蛋白）；较大的心输出量；体脂百分比较低，从而提高力量、速度、爆发力和有氧耐力等方面的运动表现（Handelsman 等人， 2018 ；Hilton & Lundberg， 2021 ；Hunter 等人， 2023 ；Nokoff 等人， 2023 ；Petek 等人.， 2023 ；Senefeld 等人， 2019 ）。此外，在整个青春期，解剖结构中不可改变的性别差异逐渐形成，因此，平均而言，男性更高；而男性则更高。四肢更长；拥有更大的肺部和更大的气道横截面积；比女性拥有更多的肌肉质量和更大的心脏（Dominelli 等人， 2019 ；Hilton & Lundberg， 2021 ；Hunter 等人， 2023 ）。由于与睾酮以及生理和解剖系统的相关适应相关的深远的表现增强作用，竞技运动在青春期期间和之后通常分为男性和女性。 男性和女性运动表现的差异在青春期非常大，这也可能部分归因于雌激素的作用（Khosla 等， 1998 ；Ober 等， 2008 ）。

Oestrogen 雌激素

Oestrogen is a broad category of sex-steroid hormones associated with the female reproductive organs and development of secondary female sex characteristics (Delgado & Lopez-Ojeda, 2023). Of the four naturally occurring oestrogens – oestrone, oestradiol, oestriol and oestetrol – oestradiol is the preponderant oestrogen among non-pregnant females during reproductive years and consequently a primary focus in biomedical research of premenopausal females. Although oestrogens are present in both males and females, before menopause, endogenous oestradiol concentrations are at least fourfold higher in adult females than males (Khosla et al., 1998; Ober et al., 2008). Despite their importance in the reproductive systems of both females and males (Delgado & Lopez-Ojeda, 2023; Finkelstein et al., 2013; Hess et al., 1997; Russell & Grossmann, 2019), oestrogens have limited anabolic effects (as opposed to testosterone) and are not a primary contributor to the large sex differences in athletic performance that involve muscle strength, power and aerobic capacity and endurance (Kong et al., 2019; Lowe et al., 2010). Oestrogens play important roles in glucose homeostasis, maintenance of bone health, immune function, cardiovascular health, fertility and neural functions in both males and females (Patel et al., 2018; Russell & Grossmann, 2019), and particularly in females, the maintenance of bone mass, skeletal muscle and tendon (Hansen, 2018; Lowe et al., 2010). Although the evidence base primarily rests on rodent models and ageing human muscle, there is emerging evidence suggesting an important mechanistic link between female sex hormones (oestrogens and progestogens) and skeletal muscle (mass, function and quality), particularly the preservation of skeletal muscle from menopausal- and age-related declines (sarcopenia) (Alexander et al., 2022; Pöllänen et al., 2015; Sipilä et al., 2006; van Geel et al., 2009). Better understanding the relationship between female sex hormones and skeletal muscle presents a key opportunity for future investigations.
雌激素是一类广泛的性类固醇激素，与女性生殖器官和女性第二性征的发育相关（Delgado & Lopez-Ojeda， 2023 ）。在四种天然雌激素（雌酮、雌二醇、雌三醇和雌四醇）中，雌二醇是育龄期非怀孕女性中最主要的雌激素，因此是绝经前女性生物医学研究的主要焦点。尽管男性和女性体内均存在雌激素，但在绝经前，成年女性的内源性雌二醇浓度至少比男性高四倍（Khosla 等， 1998 ；Ober 等， 2008 ）。尽管雌激素对女性和男性的生殖系统都很重要（Delgado & Lopez-Ojeda, 2023 ；Finkelstein et al., 2013 ；Hess et al., 1997 ；Russell & Grossmann, 2019 ），但其合成代谢作用有限（相反）睾酮），并且不是导致涉及肌肉力量、爆发力、有氧能力和耐力的运动表现存在巨大性别差异的主要因素（Kong 等人， 2019 年；Lowe 等人， 2010 年）。雌激素在男性和女性的葡萄糖稳态、维持骨骼健康、免疫功能、心血管健康、生育能力和神经功能中发挥着重要作用（Patel 等，2017）。, 2018 ; Russell & Grossmann， 2019 ），特别是对于女性，维持骨量、骨骼肌和肌腱（Hansen， 2018 ；Lowe 等人， 2010 ）。尽管证据基础主要依赖于啮齿动物模型和衰老的人类肌肉，但有新的证据表明女性性激素（雌激素和孕激素）与骨骼肌（质量、功能和质量）之间存在重要的机制联系，特别是骨骼肌的保存与更年期和年龄相关的衰退（肌肉减少症）（Alexander 等人， 2022 ；Pöllänen 等人， 2015 ；Sipilä 等人， 2006 ；van Geel 等人， 2009 ）。更好地了解女性性激素和骨骼肌之间的关系为未来的研究提供了关键机会。

Downstream actions of sex-steroid hormones during puberty contribute to improved athletic performance among both males and females and provide a clear rationale for age-related categorization in most competitive sports (Atkinson et al., 2024; Brown et al., 2024; Senefeld et al., 2019). However, female puberty may also contribute to irreversible differences in physiology and anatomy that can limit athletic performance among females compared with males, particularly during weight-bearing exercise. Females, for example, have a higher percentage of body fat than males and less muscle mass for a given body size (Bredella, 2017; Gallagher et al., 1997; Travers et al., 1995). Females also develop larger breasts than males, which create a load on the chest and a flexion torque when standing and moving upright (McGhee & Steele, 2020). The flexion torque needs to be countered by back extensor and stabilizer muscles, potentially compromising movement of the vertebrae and upper limbs (Brisbine et al., 2020; McGhee & Steele, 2020). Females also typically develop wider hips than males, creating a larger Q angle (angle between knee joint and hip joint), which is associated with higher risk and incidence of non-contact knee injuries such as patellofemoral pain, patellar subluxation, dislocation and instability, and anterior cruciate ligament injury (De Ste Croix et al., 2017; Skouras et al., 2022). Furthermore, bodily changes that occur with pregnancy and the post-partum musculoskeletal impairments that can arise, can temporarily remove females from athletic competition at the highest level, sometimes during their most competitive years (Davenport et al., 2023; Deering et al., 2018; Kimber et al., 2021). These differences can also contribute to diminished best performances by females in athletic performance and to the sex difference in performance beyond the other well-established performance-enhancing attributes of males (Hunter et al., 2023).
青春期性类固醇激素的下游作用有助于提高男性和女性的运动表现，并为大多数竞技运动中与年龄相关的分类提供明确的理由（Atkinson 等人， 2024 年；Brown 等人， 2024 年；Senefeld 等人）等， 2019 ）。然而，女性青春期也可能导致生理和解剖学上不可逆转的差异，从而限制女性与男性的运动表现，特别是在负重运动期间。例如，对于给定的体型，女性的体脂百分比高于男性，而肌肉质量较少（Bredella， 2017 ；Gallagher 等， 1997 ；Travers 等， 1995 ）。女性的乳房也比男性更大，这会在站立和直立移动时对胸部产生负荷和屈曲扭矩（McGhee & Steele， 2020 ）。屈曲扭矩需要通过背部伸肌和稳定肌来抵消，这可能会影响椎骨和上肢的运动（Brisbine 等人， 2020 ；McGhee 和 Steele， 2020 ）。女性的臀部通常比男性更宽，形成更大的 Q 角（膝关节和髋关节之间的角度），这与非接触性膝关节损伤（例如髌股疼痛、髌骨半脱位、脱位和不稳定）的风险和发生率较高相关。和前十字韧带损伤（De Ste Croix 等人， 2017 ；Skouras 等人， 2022 ）。 此外，怀孕期间发生的身体变化以及可能出现的产后肌肉骨骼损伤可能会暂时使女性无法参加最高水平的体育比赛，有时甚至是在她们竞争最激烈的年份（Davenport 等人， 2023 年；Deering 等人， 2018 ；金伯等人， 2021 ）。这些差异还可能导致女性在运动表现方面的最佳表现下降，并且导致表现上的性别差异超出男性其他公认的表现增强属性（Hunter et al., 2023 ）。

Among females, the cyclical and acute fluctuations of oestrogen and progesterone across the menstrual cycle (Sims et al., 2021) were perceived to have substantial effects on human athletic performance and were often used as reason to exclude females from assessment and testing in human performance studies (Meignié et al., 2022; Sims & Heather, 2018). In contrast to these earlier beliefs, human motor performance varies minimally in magnitude across the menstrual cycle in eumenorrheic females as a group (DʼSouza et al., 2023; McNulty et al., 2020; Piasecki et al., 2023) and also varies little due to contraception options that might alter hormone fluctuations, such as oral contraceptive pills (Elliott-Sale et al., 2020). The findings supporting this broad view have recently been extensively reviewed (DʼSouza et al., 2023). For the unknown effects of these cycling hormones on physiology and function in females, and with an a priori hypothesis in place, biomedical researchers should monitor menstrual cycle status using rigorous methodologies as outlined previously (Elliott-Sale et al., 2021; Hirschberg, 2022). For comparison of human performance between males and females, however, there is little evidence that the menstrual cycle needs to be controlled (DʼSouza et al., 2023) on a large scale. Rather than be used as a rationale to exclude the study of females from research (DʼSouza et al., 2023; Meignié et al., 2022), biomedical researchers are encouraged to record descriptive information about the menstrual cycle (e.g. day of menstrual cycle) and potential physical symptoms specific to an individual (e.g. menstrual pain) that may explain poor performance on a given day, but without needing to control for the menstrual cycle phase across all females. Important to the focus of this review, the sex differences in athletic performance involving muscle strength, power, speed and aerobic endurance are considerably larger than the variations in performance across the menstrual cycle within a female.
在女性中，雌激素和孕激素在月经周期中的周期性和剧烈波动（Sims 等人， 2021 ）被认为对人类运动表现产生重大影响，并且经常被用作将女性排除在人类表现评估和测试之外的理由研究（Meignié 等人， 2022 ；Sims 和 Heather， 2018 ）。与这些早期的观点相反，月经周期中女性作为一个群体，人类运动表现在整个月经周期中的变化幅度很小（D'Souza 等人， 2023 ；McNulty 等人， 2020 ；Piasecki 等人， 2023 ），而且变化也很小。由于避孕选择可能会改变激素波动，例如口服避孕药（Elliott-Sale 等人， 2020 ）。支持这一广泛观点的研究结果最近得到了广泛的审查（D'Souza 等人， 2023 ）。由于这些循环激素对女性生理和功能的未知影响，并且有了先验假设，生物医学研究人员应该使用先前概述的严格方法来监测月经周期状态（Elliott-Sale 等人， 2021 年；Hirschberg， 2022 年） ）。然而，为了比较男性和女性之间的人类表现，几乎没有证据表明需要大规模控制月经周期（D'Souza 等人， 2023 ）。而不是用作将女性研究排除在研究之外的理由（D'Souza 等，2017）。, 2023 ; Meignié 等人， 2022 ），鼓励生物医学研究人员记录有关月经周期（例如月经周期的日期）和个人特有的潜在身体症状（例如月经疼痛）的描述性信息，这些症状可能解释特定日期的表现不佳，但无需控制所有女性的月经周期阶段。对于本次审查的重点来说，重要的是，涉及肌肉力量、力量、速度和有氧耐力的运动表现的性别差异比女性整个月经周期的表现差异要大得多。

Sexual differentiation before puberty
青春期前的性别分化

Sexual differentiation is a complex process which begins early in fetal life. As described above, sex is determined by the sex chromosome complement and gonadal development depends on the presence or absence of the SRY gene (Renault et al., 2020). In the presence of the SRY gene, gonadal development will follow a male pathway including Leydig cell differentiation which in turn produce testosterone when stimulated by activation of the hypothalamic-pituitary-gonadal (HPG) hormone axis (Lanciotti et al., 2018; Sekido & Lovell-Badge, 2013). In the absence of the SRY gene, gonadal development will follow a female pathway including ovary development and it is unknown whether there is a female-determining gene or parallel transcription factor to the SRY gene initiating ovary development (DiNapoli & Capel, 2008). After the initiation of gonadal development and differentiation, sex hormones regulate continued phenotypic development, genetic programming and sexual dimorphism (Hiort, 2013).
性别分化是一个复杂的过程，在胎儿生命的早期就开始了。如上所述，性别由性染色体补体决定，性腺发育取决于 SRY 基因的存在与否（Renault et al., 2020 ）。在 SRY 基因存在的情况下，性腺发育将遵循男性途径，包括 Leydig 细胞分化，当下丘脑 - 垂体 - 性腺 (HPG) 激素轴的激活刺激时，Leydig 细胞分化又会产生睾酮 (Lanciotti et al., 2018 ; Sekido &洛弗尔-徽章， 2013 ）。在缺乏SRY基因的情况下，性腺发育将遵循女性途径，包括卵巢发育，并且尚不清楚是否存在女性决定基因或与启动卵巢发育的SRY基因平行的转录因子（DiNapoli＆Capel， 2008 ）。性腺发育和分化开始后，性激素调节持续的表型发育、遗传编程和性二态性（Hiort， 2013 ）。

Although much is known about somatic changes associated with puberty – changing sex hormone concentrations, changes in body composition, growth spurt and development of secondary sex characteristics (Beunen & Malina, 1988; Hunter et al., 2023) – less is known about the role of sex hormones before puberty (Becker & Hesse, 2020) and their effects on athletic performance in pre-pubertal boys and girls. There are two transient activations of the HPG hormone axis before puberty that are associated with large, temporary sex differences in endogenous testosterone concentrations: first, in fetal life (during the first two trimesters of gestation) and second, in neonatal life (‘minipuberty’ occurring between three and six months of life) (Renault et al., 2020). Available evidence suggests that newborn boys weigh more and have more fat-free mass than girls (Fryar et al., 2021; Veldhuis et al., 2005), boys accumulate less fat mass than girls during childhood (Veldhuis et al., 2005), and boys may have faster growth velocities than girls during early infancy, associated with higher postnatal testosterone surges (Kiviranta et al., 2016). These sex differences in body composition may confer an athletic advantage among boys compared with girls before ages associated with puberty and adolescence (Atkinson et al., 2024; Brown et al., 2024; Senefeld & Hunter, 2024). However, findings of sex differences in body composition and athletic performance during childhood are inconsistent (Becker & Hesse, 2020; Hunter et al., 2023), with a recent study showing no sex differences in glycolytic capacity and fibre type size of skeletal muscle among children aged 9–12 years (Esbjörnsson et al., 2022). The two transient activations of the HPG hormone axis are an understudied area with many opportunities for future studies.
尽管人们对青春期相关的躯体变化了解很多——性激素浓度的变化、身体成分的变化、生长突增和第二性征的发育（Beunen & Malina, 1988 ；Hunter et al., 2023 ），但对其作用却知之甚少。青春期前性激素的变化（Becker & Hesse， 2020 ）及其对青春期前男孩和女孩运动表现的影响。青春期前 HPG 激素轴有两种短暂激活，与内源性睾酮浓度的暂时性巨大性别差异相关：首先是在胎儿期（妊娠的前两个三个月），其次是在新生儿期（“小青春期”）发生在出生后三到六个月之间）（Renault et al., 2020 ）。现有证据表明，新生男孩比女孩体重更重，无脂肪质量也更多（Fryar et al., 2021 ；Veldhuis et al., 2005 ），男孩在童年时期比女孩积累更少的脂肪质量（Veldhuis et al., 2005 ） ，并且在婴儿早期，男孩的生长速度可能比女孩更快，这与出生后睾酮激素激增有关（Kiviranta 等人， 2016 ）。在与青春期和青春期相关的年龄之前，这些身体成分的性别差异可能会赋予男孩相对于女孩的运动优势（Atkinson 等人， 2024 年；Brown 等人， 2024 年；Senefeld 和 Hunter， 2024 年）。 然而，关于儿童时期身体成分和运动表现的性别差异的研究结果并不一致（Becker & Hesse， 2020 ；Hunter 等， 2023 ），最近的一项研究表明，在糖酵解能力和骨骼肌纤维类型大小方面没有性别差异。 9-12 岁的儿童（Esbjörnsson 等人， 2022 ）。 HPG 激素轴的两种短暂激活是一个尚未充分研究的领域，未来有很多研究机会。

Mechanisms for the sex differences in strength and power
力量和功率性别差异的机制

The mechanisms for the large sex differences in maximal strength and power are primarily of muscular origin with minimal differences in neural drive. The sex differences in morphology and composition of human skeletal muscle and the resultant metabolic capacity and contractile properties of similarly trained males and females are ultimately due to sex-related differences in human skeletal muscle gene expression and the interaction with sex-specific hormones and training status (Chapman et al., 2020; Landen et al., 2021; Liu et al., 2010; Maher et al., 2009; Roth et al., 2002; Welle et al., 2008).
最大力量和功率方面存在巨大性别差异的机制主要是肌肉起源，而神经驱动方面的差异很小。人类骨骼肌形态和组成的性别差异，以及由此产生的经过类似训练的男性和女性的代谢能力和收缩特性，最终是由于人类骨骼肌基因表达的性别相关差异以及与性别特异性激素和训练状态的相互作用造成的。 （Chapman 等人， 2020 ；Landen 等人， 2021 ；Liu 等人， 2010 ；Maher 等人， 2009 ；Roth 等人， 2002 ；Welle 等人， 2008 ）。

While maximal muscle strength is largely dependent on the cross-sectional area of a muscle (Lieber & Fridén, 2000; Maughan et al., 1983; Narici, 1999), power is the product of force (strength) and contractile velocity, both of which are greater in the skeletal muscles of males than females (e.g. Alcazar et al., 2020; Wrucke et al., 2023). Skeletal muscles of males on average produce more maximal force/torque during both static and dynamic contractions than females because the mass and cross-sectional area of skeletal muscles is larger in males (Bartolomei et al., 2021; Gallagher et al., 1997; Lindle et al., 1997; Suetta et al., 2019). The greater muscle mass of males is primarily due to a larger cross-sectional area of all muscle fibre types (Larsson et al., 2006; Toft et al., 2003), with the largest sex difference in type II (fast) muscle fibres (Alway et al., 1989; Esbjornsson-Liljedahl et al., 1999; Fournier et al., 2022; Grosicki et al., 2022; Haizlip et al., 2015; Nuzzo, 2024; Porter et al., 2002; Staron et al., 2000; Trappe et al., 2003). Best estimates indicate the absolute number of fibres within a muscle does not differ between the sexes (Miller et al., 1993) although this is difficult to assess experimentally. Although the cross-sectional area of muscle fibres is larger in males than females, single-fibre studies indicate that the specific tension (force per unit cross-sectional area) of the fibres is similar between the sexes in young and older adults (Frontera et al., 2000; Grosicki et al., 2022; Krivickas et al., 2006; Teigen et al., 2020; Trappe et al., 2003). Thus, the greater muscle strength exerted by males compared with females is primarily due to a larger muscle volume among males.
虽然最大肌肉力量很大程度上取决于肌肉的横截面积（Lieber & Fridén， 2000 ；Maughan 等， 1983 ；Narici， 1999 ），但功率是力（力量）和收缩速度的乘积，两者都是男性的骨骼肌比女性的骨骼肌更大（例如 Alcazar 等人， 2020 ；Wrucke 等人， 2023 ）。男性骨骼肌在静态和动态收缩过程中平均比女性产生更多的最大力/扭矩，因为男性骨骼肌的质量和横截面积更大（Bartolomei et al., 2021 ；Gallagher et al., 1997 ； Lindle 等人， 1997 ；Suetta 等人， 2019 ）。男性的肌肉质量较大，主要是由于所有肌纤维类型的横截面积较大（Larsson 等， 2006 ；Toft 等， 2003 ），其中 II 型（快）肌纤维的性别差异最大（Alway 等人， 1989 ；Esbjornsson-Liljedahl 等人， 1999 ；Fournier 等人， 2022 ；Grosicki 等人， 2022 ；Haizlip 等人， 2015 ；Nuzzo， 2024 ；Porter 等人， 2002 ；Staron等人， 2000 ；特拉普等人， 2003 ）。 最佳估计表明，肌肉内纤维的绝对数量在性别之间没有差异（Miller 等人， 1993 ），尽管这很难通过实验进行评估。尽管男性肌纤维的横截面积大于女性，但单纤维研究表明，年轻人和老年人的不同性别之间纤维的比张力（每单位横截面积的力）相似（Frontera 等）等人， 2000 ；Grosicki 等人， 2022 ；Krivickas 等人， 2006 ；Teigen 等人， 2020 ；Trappe 等人， 2003 。因此，与女性相比，男性发挥更大的肌肉力量主要是由于男性的肌肉体积更大。

The contractile speed of whole muscle is faster among males than females largely because the whole muscle of females possesses a greater relative area of type I (slow) fibres and a smaller relative area of the type II (fast) fibres compared with males (Esbjornsson-Liljedahl et al., 1999; Hunter et al., 2023; Nuzzo, 2024; Staron et al., 2000). Type II (fast) muscle fibres of males are relatively bigger than those in females so that this sex difference in muscle fibre size is greater for type II than for type I (slow) fibres (Esbjornsson-Liljedahl et al., 1999; Fournier et al., 2022; Hunter et al., 2023; Maher et al., 2009; Roepstorff et al., 2006; Staron et al., 2000; Teigen et al., 2020). Consequently, the larger whole muscle of males has proportionally more type II (fast) fibre area than females. Accordingly, myosin heavy chain (MHC) analysis of skeletal muscle fibres extracted from muscle biopsies typically shows females with higher relative content of MHC I than males and lower MHC II content (Galvan-Alvarez et al., 2023; Staron et al., 2000).
男性整体肌肉的收缩速度比女性更快，很大程度上是因为与男性相比，女性整体肌肉具有较大的 I 型（慢速）纤维相对面积和较小的 II 型（快）纤维相对面积（Esbjornsson- Liljedahl 等人， 1999 ；Hunter 等人， 2023 ；Staron 等人， 2000 ）。男性的 II 型（快）肌纤维相对大于女性，因此 II 型肌纤维大小的性别差异比 I 型（慢）纤维更大（Esbjornsson-Liljedahl 等， 1999 ；Fournier 等）等人， 2022 ；Maher 等人， 2009 ；Staron等人， 2000 ；因此，男性较大的整体肌肉比女性具有更多的 II 型（快）纤维面积。因此，对从肌肉活检中提取的骨骼肌纤维进行肌球蛋白重链 (MHC) 分析通常显示，女性的 MHC I 相对含量高于男性，而 MHC II 含量较低（Galvan-Alvarez 等人， 2023 年；Staron 等人， 2000 年） ）。

Relative area of type II fibres could also be larger in the whole muscle of males if they possessed a larger relative number of type II fibres (% composition or % distribution) than in females. Several studies report the percentage composition of fibre types do not significantly differ between males and females (e.g. Carter et al., 2001; Esbjornsson-Liljedahl et al., 1999; Larsson et al., 2006; Porter et al., 2002; Staron et al., 2000; Toft et al., 2003). However, others found the composition (%) of type I muscle fibres was greater in females than males, with differences varying between ∼3% and 13% in the vastus lateralis (Fournier et al., 2022; Maher et al., 2009; Roepstorff et al., 2006; Simoneau & Bouchard, 1989). Accordingly, a recent meta-analysis reported a small-to-moderate effect size for females expressing 2.6% more type I fibre (% composition) than males (Nuzzo, 2024). Type II fibres generate more peak force than type I fibres and over twice maximal shortening velocity and peak power than type I fibres (Bottinelli et al., 1996; Sundberg, Hunter et al., 2018; Teigen et al., 2020; Trappe et al., 2003). These findings further support the suggestion that males have faster contractile properties than females because of a larger relative type II fibre area in their whole muscle than females.
如果男性拥有比女性更多的 II 型纤维相对数量（组成百分比或分布百分比），则男性整个肌肉中 II 型纤维的相对面积也可能更大。一些研究表明，男性和女性之间纤维类型的百分比组成没有显着差异（例如 Carter 等人， 2001 ；Esbjornsson-Liljedahl 等人， 1999 ；Larsson 等人， 2006 ；Porter 等人， 2002 ；Staron等人， 2000 ；托夫特等人， 2003 ）。然而，其他人发现女性 I 型肌纤维的组成（%）高于男性，股外侧肌的差异在 ∼3% 到 13% 之间（Fournier 等人， 2022 年；Maher 等人， 2009 年； Roepstorff 等人， 2006 ；Simoneau 和 Bouchard， 1989 ）。因此，最近的一项荟萃​​分析报告称，女性表达的 I 型纤维（组成百分比）比男性多 2.6%，其效应大小为小到中等（Nuzzo， 2024 ）。 II 型纤维比 I 型纤维产生更多的峰值力，并且比 I 型纤维产生超过两倍的最大缩短速度和峰值功率（Bottinelli 等人， 1996 ；Sundberg、Hunter 等人， 2018 ；Teigen 等人， 2020 ；Trappe 等人等， 2003 ）。 这些发现进一步支持了以下观点：男性比女性具有更快的收缩特性，因为其整个肌肉中的相对 II 型纤维面积比女性更大。

Consequently, the skeletal muscle of males is larger in volume with relatively a larger fast-contracting type II fibre area than females. The sex difference in maximal muscular power of a single limb, therefore, is considerable (up to 50% larger) in males compared with females of similar training status and age, and larger than the sex difference in maximal strength (Alcazar et al., 2020; Bartolomei et al., 2021; Sundberg, Kuplic et al., 2018; Trappe et al., 2003; Wrucke et al., 2023).
因此，男性的骨骼肌体积比女性更大，具有相对更大的快速收缩II型纤维面积。因此，与训练状态和年龄相似的女性相比，男性单肢最大肌肉力量的性别差异相当大（高达 50%），并且大于最大力量的性别差异（Alcazar 等人， 2020 ；Bartolomei 等人， 2021 ；Sundberg、Kuplic 等人， 2018 ；Trappe 等人， 2003 ；

Similar to single-limb exercise, males exert up to ∼50% greater anaerobic power (work per unit time) than females during maximal, short-term whole-body exercise including cycling, running, skiing, jumping and swimming (Bulbulian et al., 1996; Esbjornsson et al., 1993; Esbjornsson-Liljedahl et al., 2002; Maud & Shultz, 1986; Mayhew & Salm, 1990; Mayhew et al., 2001; Murphy et al., 1986; Perez-Gomez et al., 2008; Sollie & Losnegard, 2022; Weber et al., 2006; Zera et al., 2022). Anaerobic power is associated with size of the exercising limbs and the volume of muscle utilized: it reflects capacity of intramuscular high-energy phosphates (adenosine triphosphate (ATP) and phosphocreatine (PCr)) and anaerobic glycolysis (Maud & Shultz, 1986; Weber et al., 2006). Most of the sex difference in anaerobic power is explained by muscle mass, although some sex difference remains during arm exercise and more prolonged sprints (Bartolomei et al., 2021; Hübner-Woźniak et al., 2004; Maud & Shultz, 1986; Perez-Gomez et al., 2008; Weber et al., 2006). The sex differences in normalized anaerobic power are likely due to the greater power and glycolytic capacity of type II fibres (Esbjornsson et al., 1993; Green et al., 1984; Jaworowski et al., 2002; Komi & Karlsson, 1978) which, as discussed above, are larger in proportional area in the skeletal muscle of males compared with females. The consequences for repeated contractions and fatigability of limb muscles are related to sex differences in fibre types and discussed in the section ‘Performance fatigability’.
与单肢运动类似，在最大程度的短期全身运动（包括骑自行车、跑步、滑雪、跳跃和游泳）中，男性的无氧能力（单位时间做功）比女性高出约 50%（Bulbulian 等人，2017）。 ， 1996 ； Esbjornsson-Liljedahl等， 1986 ；Mayhew等， 1986 ； ., 2008 ; Sollie 和 Losnegard, 2022 ; Weber 等人, 2006 ; Zera 等人, 2022无氧功率与运动肢体的大小和所用肌肉的体积有关：它反映了肌内高能磷酸盐（三磷酸腺苷（ATP）和磷酸肌酸（PCr））和无氧糖酵解的能力（Maud＆Shultz， 1986 ；Weber等）等， 2006 ）。大多数无氧能力的性别差异可以通过肌肉质量来解释，尽管在手臂锻炼和更长时间的冲刺期间仍然存在一些性别差异（Bartolomei et al., 2021 ; Hübner-Woźniak et al., 2004 ; Maud & Shultz, 1986 ; Perez -戈麦斯等人， 2008 ；韦伯等人， 2006 ）。 标准化无氧能力的性别差异可能是由于 II 型纤维的更大的功率和糖酵解能力（Esbjornsson 等人， 1993 年；Green 等人， 1984 年；Jaworowski 等人， 2002 年；Komi 和 Karlsson， 1978 年），如上所述，与女性相比，男性骨骼肌的比例面积更大。肢体肌肉反复收缩和疲劳的后果与纤维类型的性别差异有关，并在“性能疲劳”部分中讨论。

Healthy males and females have similar neural drive during maximal effort contractions
健康男性和女性在最大努力收缩期间具有相似的神经驱动

Sex differences in skeletal muscle force and power production during single-limb maximal efforts are not associated with neural mechanisms or an inability of the central nervous system to adequately activate skeletal muscle. Evidence supports the proposition that neural drive or voluntary activation is similar between males and females during maximal effort contractions of skeletal muscle using several different stimulation modalities, including contractions evoked using electrical stimulation of the motor nerve or muscle; transcranial magnetic stimulation of the motor cortex; and superimposed stimuli during maximal effort contractions (Ansdell et al., 2019; Besson et al., 2021; Hunter et al., 2006; Keller et al., 2011; Kent-Braun & Ng, 1999; Molenaar et al., 2013; Senefeld et al., 2018; Temesi et al., 2015; Yoon et al., 2015). The similar and near maximal levels of voluntary activation during single-limb contractions of males and females indicate that muscular mechanisms rather than neural mechanisms are primarily responsible for the larger power output of males than females for single-limb exercise and cycling in young and older adults (Perez-Gomez et al., 2008; Wrucke et al., 2023). The erroneous and pervasive notion that sex differences in skeletal muscle function (e.g. strength, power, performance fatigability) in laboratory studies are because females ‘do not try as hard’ as males is refuted by voluminous scientific evidence, some of which is referenced above and elsewhere (Nuzzo, 2023).
单肢最大努力期间骨骼肌力量和功率产生的性别差异与神经机制或中枢神经系统无法充分激活骨骼肌无关。有证据支持这一观点，即在使用几种不同的刺激方式（包括使用运动神经或肌肉的电刺激引起的收缩）进行骨骼肌的最大努力收缩期间，男性和女性之间的神经驱动或自愿激活是相似的；运动皮层的经颅磁刺激；以及最大努力收缩期间的叠加刺激（Ansdell et al., 2019 ; Besson et al., 2021 ; Hunter et al., 2006 ; Keller et al., 2011 ; Kent-Braun & Ng, 1999 ; Molenaar et al., 2013 ；Senefeld 等人， 2018 ；Temesi 等人， 2015 ；Yoon 等人， 2015 ）。男性和女性单肢收缩期间的自愿激活水平相似且接近最大水平，这表明肌肉机制而不是神经机制是男性在年轻人和老年人的单肢运动和骑自行车中比女性更大的功率输出的主要原因（Perez-Gomez 等人， 2008 年；Wrucke 等人， 2023 年）。骨骼肌功能存在性别差异的错误且普遍的观念（例如 实验室研究中认为女性“不像男性那样努力”，是因为女性“不像男性那样努力”，这一点已被大量科学证据反驳，其中一些证据在上文和其他地方引用（Nuzzo， 2023 ）。

Sex differences in performance fatigability of limb muscles are task dependent
肢体肌肉疲劳性能的性别差异取决于任务

The magnitude of the sex difference in performance fatigability of single-limb exercise, however, changes with contraction velocity for the lower limb – as contraction velocity increases, the sex difference (greater fatigability of males compared with females) is diminished in young adults (Hunter, 2016b). During fast-dynamic contractions, sex differences in performance fatigability of single-limb contractions are primarily minimal for lower-limb exercise in both young and old adults (Hunter, 2016b; Senefeld et al., 2013, 2018; Sundberg, Kuplic et al., 2018). In contrast, for upper-limb muscles (elbow flexor muscles), older males were more fatigable than older females for moderate-to-fast velocity dynamic contractions (Lewis et al., 2022; Senefeld et al., 2017; Yoon et al., 2015).
然而，单肢运动表现疲劳性的性别差异程度随着下肢收缩速度的变化而变化——随着收缩速度的增加，年轻人中的性别差异（男性比女性更大的疲劳性）减少（Hunter ， 2016b ）。在快速动态收缩期间，年轻人和老年人的下肢运动中，单肢收缩的疲劳性的性别差异基本上很小（Hunter， 2016b ；Senefeld 等人， 2013，2018 ；Sundberg，Kuplic 等人，2018）。 ， 2018 ）。相比之下，对于上肢肌肉（肘屈肌），老年男性比老年女性更容易疲劳，进行中速至快速的动态收缩（Lewis et al., 2022 ；Senefeld et al., 2017 ；Yoon et al.，2017）。 ， 2015 ）。

For whole-body dynamic exercise, the findings on sex difference in performances fatigability are varied. Consistent with the single-limb exercise, females exhibited less fatigability than males during or after multiple sprint exercise (Billaut & Bishop, 2009), including cycling (Billaut & Bishop, 2012) and running (Laurent et al., 2010). The sex differences were largely accounted for by the greater mechanical work required of the males compared with females (Billaut & Bishop, 2012) and presumably the higher metabolic demands. However, consistent with fast-dynamic single-limb contractions, there were minimal sex differences in the relative critical power of males and females during cycling exercise on the power–duration curve (Ansdell, Škarabot et al., 2020; James, Leach et al., 2023; Sundberg et al., 2017). While anaerobic capacity was greater in males than females, there were no sex differences in lower-limb cycling time-to-failure (∼2.4 min) at 120% power of VO_{2 max} (Martin-Rincon et al., 2021). Thus, while the sex difference in lower-limb exercise performance appears to be diminished with fast-dynamic contractions in the lower limb during single-limb repeated contractions, some studies suggest that females are less fatigable than males during upper-limb exercise and in some whole-body exercises, that may be accounted for by initial absolute mechanical work.
对于全身动态运动，疲劳性能的性别差异的研究结果各不相同。与单肢运动一致，女性在多次冲刺运动期间或之后表现出比男性更少的疲劳性（Billaut＆Bishop， 2009 ），包括骑自行车（Billaut＆Bishop， 2012 ）和跑步（Laurent等人， 2010 ）。性别差异主要是由于与女性相比，男性需要做更多的机械工作（Billaut & Bishop， 2012 ），并且可能需要更高的代谢需求。然而，与快速动态单肢收缩一致，在自行车运动期间，男性和女性的相对临界功率在功率-持续时间曲线上存在最小的性别差异（Ansdell，Škarabot 等人， 2020 ；James，Leach 等人） .， 2023 ；桑德伯格等人， 2017 ）。虽然男性的无氧能力高于女性，但在_{最大摄氧量 2}的 120% 功率下，下肢循环至力竭的时间（~2.4 分钟）没有性别差异（Martin-Rincon 等人， 2021 ）。因此，虽然下肢运动表现的性别差异似乎随着单肢重复收缩期间下肢的快速动态收缩而减小，但一些研究表明，女性在上肢运动期间比男性不易疲劳，并且在某些情况下，女性比男性更不易疲劳。全身锻炼，可以通过初始绝对机械功来解释。

The primary mechanisms contributing to sex differences in performance fatigability during the isometric and slow-dynamic contractions are muscular (contractile) in origin (Ansdell et al., 2019; Hunter et al., 2006; Keller et al., 2011; Senefeld et al., 2018) and persistent across the lifespan (Yoon et al., 2015). For sustained isometric tasks, the greater strength of males (due to a larger muscle mass) can play a primary role in limiting blood flow in males more rapidly than females during low-to-moderate force sustained isometric contractions performed at the same relative intensity (Hunter & Enoka, 2001). The larger absolute forces and greater intramuscular pressures exerted on the feed arteries during sustained contractions can limit perfusion and oxygen supply in males more than females, resulting in an increased rate of metabolite buildup in the males. Accordingly, the metaboreflex (pressor response: increased in mean arterial pressure with contraction (Mitchell & Victor, 1996; Rowell & OʼLeary, 1990)) was greater in males than females and associated with the initial absolute strength in the elbow flexor mucles (Hunter & Enoka, 2001). When the isometric fatiguing-contraction task was intermittent, however, the muscle was relatively perfused and the females outperformed the males (longer time to task failure) even when matched for strength (Hunter et al., 2004, 2009).
等长收缩和慢动态收缩期间导致疲劳性能性别差异的主要机制是肌肉（收缩）（Ansdell 等人， 2019 ；Hunter 等人， 2006 ；Keller 等人， 2011 ；Senefeld 等人） ., 2018 ）并在整个生命周期中持续存在（Yoon 等人， 2015 ）。对于持续的等长收缩任务，男性的更大力量（由于肌肉质量更大）可以在以相同相对强度进行低到中等力量的持续等长收缩期间比女性更快地限制男性血流方面发挥主要作用。亨特和伊诺卡， 2001 ）。在持续收缩过程中，施加在供血动脉上的绝对力和肌内压力更大，可能比女性更能限制雄性的灌注和氧气供应，导致雄性代谢物积累的速度增加。因此，男性的代谢反射（升压反应：平均动脉压随着收缩而增加（Mitchell & Victor， 1996 ；Rowell & O'Leary， 1990 ））比女性更大，并且与肘屈肌的初始绝对强度相关（Hunter &伊诺卡， 2001 ）。然而，当等长疲劳收缩任务是间歇性的时，肌肉相对灌注，即使在力量匹配的情况下，女性的表现也优于男性（任务失败的时间更长）（Hunter et al., 2004, 2009 ）。

There are several other possible mechanisms for the sex difference in fatigability during dynamic or intermittent tasks that are not explained by muscle mass – one involves a sex difference in skeletal muscle metabolism that is related to differences between males and females in fibre type proportional area and the effects on contractile function (Billaut & Bishop, 2009; Esbjornsson et al., 1993; Maher et al., 2009). Males demonstrate a greater glycolytic capacity than females (Esbjornsson et al., 1993; Green et al., 1984; Jaworowski et al., 2002; Komi & Karlsson, 1978) and females typically demonstrate greater oxidative capacity of whole muscle than males (Esbjornsson et al., 1993, 2012; Russ et al., 2005). Accordingly, in response to a fatiguing contraction with a single limb, females exhibit a smaller reduction of the contractile function such as relaxation rates (that reflect fibre types’ proportional areas) compared with males (e.g. Hunter et al., 2006; Senefeld et al., 2018; Yoon et al., 2015). Other mechanisms, however, may also contribute to the sex differences in fatigability including differences in muscle perfusion and blood flow due to vasodilatation and sympathetic activation, which can be larger in females than males (Hunter et al., 2009; Kellawan et al., 2015; Parker et al., 2007). Sex differences in perfusion or fibre type proportional area can both lead to a larger and more rapid accumulation of fatigue-inducing metabolites in males relative to females during fatiguing exercise, and greater fatigability of males than females.
在动态或间歇性任务中，疲劳性的性别差异还有其他几种可能的机制，这些机制无法用肌肉质量来解释——其中之一涉及骨骼肌代谢的性别差异，与男性和女性之间纤维类型比例面积和肌肉质量的差异有关。对收缩功能的影响（Billaut & Bishop， 2009 ；Esbjornsson 等， 1993 ；Maher 等， 2009 ）。男性比女性表现出更强的糖酵解能力（Esbjornsson 等人， 1993 年；Green 等人， 1984 年；Jaworowski 等人， 2002 年；Komi 和 Karlsson， 1978 年），并且女性通常比男性表现出更大的整个肌肉氧化能力（Esbjornsson）等人， 1993 年，2012 年；拉斯等人， 2005 年）。因此，与男性相比，为了应对单肢的疲劳收缩，女性表现出收缩功能的较小程度的降低，例如松弛率（反映纤维类型的比例面积）（例如 Hunter 等人， 2006 年；Senefeld 等人） .， 2018 ；尹等人， 2015 ）。然而，其他机制也可能导致疲劳性的性别差异，包括由于血管舒张和交感神经激活而导致的肌肉灌注和血流差异，女性的差异可能大于男性（Hunter 等， 2009 ；Kellawan 等， 2015 ；帕克等人。， 2007 ）。灌注或纤维类型比例面积的性别差异都可以导致在疲劳运动期间男性相对于女性疲劳诱导代谢物的更大和更快的积累，并且男性比女性更容易疲劳。

Notably, however, greater afferent feedback in response to a large accumulation of metabolites from the contracting skeletal muscle among males (larger metaboreflex, e.g. Hunter & Enoka, 2001; Jarvis et al., 2011; Samora et al., 2019) have led in some instances to larger reductions in neural drive (reductions in voluntary activation, i.e. central fatigue) compared with females during high-intensity isometric tasks of the lower-limb muscles (Martin & Rattey, 2007; Russ & Kent-Braun, 2003). The larger central fatigue (in males, however, is not observed in upper-limb muscles (Hunter et al., 2006; Keller et al., 2011; Yoon et al., 2007). Collectively, however, the limited sex differences in neural drive during fatiguing contractions is not the primary mechanism for greater fatigability of males than females.
然而，值得注意的是，男性收缩骨骼肌代谢物大量积累时产生的更大的传入反馈（更大的代谢反射，例如 Hunter & Enoka， 2001 ；Jarvis 等， 2011 ；Samora 等， 2019 ）导致了在某些情况下，与女性相比，在下肢肌肉进行高强度等长训练时，神经驱动力会大幅下降（自愿激活减少，即中枢疲劳）（Martin & Rattey， 2007 ；Russ & Kent-Braun， 2003 ）。较大的中枢疲劳（然而，在男性中，上肢肌肉中没有观察到这种情况（Hunter 等人， 2006 年；Keller 等人， 2011 年；Yoon 等人， 2007 年）。然而，总的来说，性别差异有限疲劳收缩期间的神经驱动并不是男性比女性更易疲劳的主要机制。

While considerable research has emerged to understand the sex differences in fatigability during fatiguing exercise in the last 25 years (Hicks et al., 2001; Hunter, 2014, 2024), less is known about recovery from a fatiguing bout of exercise. Key opportunities for further studies involve understanding the impact of sex differences during fatiguing exercise on short- and long-term recovery, in response to isometric and dynamic contractions of all velocities and whole-body exercise (Laurent et al., 2010; Martin-Rincon et al., 2021; Senefeld et al., 2018).
虽然在过去 25 年中已经开展了大量研究来了解疲劳运动期间疲劳性的性别差异（Hicks 等， 2001 ；Hunter， 2014，2024 ），但人们对从疲劳运动中恢复的了解却很少。进一步研究的关键机会包括了解疲劳运动期间性别差异对短期和长期恢复的影响，以响应所有速度和全身运动的等长收缩和动态收缩（Laurent 等人， 2010 ；Martin-Rincon）等人， 2021 ；Senefeld 等人， 2018 ）。