The dependence of preferred competitive racing distance on muscle fibre type composition and ACTN3 genotype in speed skaters
The dependence of preferred competitive racing distance on muscle fibre type composition and ACTN3 genotype in speed skaters
复制标题
DOI：
10.1113/expphysiol.2011.060293
复制
发表时间：
2011-12-01
影响因子：
2.7
通讯作者：
Williams, Alun G.
中科院分区：
文献类型：
--
作者：
Ahmetov, Ildus I.;Druzhevskaya, Anastasiya M.;Williams, Alun G.
人们普遍认为肌纤维成分会影响体能表现。a-肌动蛋白-3 （ACTN3）基因R577X多态性被怀疑是决定肌纤维类型组成和运动状态的基因变异之一。在本研究中，我们研究了34名参加不同长度（500 - 10 000米）比赛的俄罗斯速滑运动员（20名男子和14名女子）的平均首选比赛距离（PRD）对股外侧肌肌纤维类型组成的依赖性。我们还研究了94名受试者（60名身体活跃的健康男性和34名速滑运动员）的ACTN3多态性与肌纤维特征之间的关系，以及115名亚细亚和精英速滑运动员的PRD与ACTN3基因型之间的关系。并将115名速滑运动员的ACTN3基因型和等位基因频率与1301名对照进行比较。与对照组相比，短跑运动员（n = 39）的actn3xx基因型频率显著降低（2.6 vs 14.5%; P = 0.034）。我们观察到PRD与慢肌纤维比例之间的正相关关系接近线性，但更适合对数曲线（r = 0.593, P < 0.0005）。ACTN3 R577X多态性与肌纤维组成相关(慢肌纤维：RR基因型，51.7 (12.8)%；Rx, 57.4% (13.2)%；Xx 61.5 (16.3)%；？= 0.215;P = 0.049)，所有运动员的PRD (？= 0.24, P = 0.010)，表明actn3xx基因型携带者表现出更高比例的慢肌纤维，并且更喜欢滑冰长距离比赛。然而，肌纤维类型和PRD之间的大部分关联与ACTN3基因型无关。综上所述，ACTN3 R577X多态性与速滑运动员偏好的比赛距离和肌肉纤维类型组成有关。因此，R577X多态性可能部分通过与纤维类型的关联，有助于在速度滑冰中发挥高水平能力的一个小但可能重要的组成部分。
It is generally accepted that muscle fibre composition may influence physical performance. The a-actinin-3 (ACTN3) gene R577X polymorphism is suspected to be one of the contributing gene variations in the determination of muscle fibre type composition and athletic status. In the present study, we examined the dependence of average preferred racing distance (PRD) on muscle fibre type composition of the vastus lateralis muscle in 34 subelite Russian speed skaters (20 men and 14 women) who competed in races of different length (50010,000 m). We also investigated the association between the ACTN3 polymorphism and muscle fibre characteristics in 94 subjects (60 physically active healthy men and 34 speed skaters), as well as the relationship between PRD and ACTN3 genotype in 115 subelite and elite speed skaters. In addition, ACTN3 genotype and allele frequencies of the 115 speed skaters were compared with 1301 control subjects. The ACTN3 XX genotype frequency was significantly lower in sprinters (n = 39) compared with control subjects (2.6 versus 14.5%; P = 0.034). We observed a positive relationship between PRD and the proportion of slow-twitch muscle fibres that was close to linear, but better fitted a logarithmic curve (r = 0.593, P < 0.0005). The ACTN3 R577X polymorphism was associated with muscle fibre composition (slow-twitch fibres: RR genotype, 51.7 (12.8)%; RX, 57.4 (13.2)%; XX 61.5 (16.3)%; ?= 0.215; P = 0.049) in the overall muscle biopsy group, and with PRD of all athletes (?= 0.24, P = 0.010), indicating that ACTN3 XX genotype carriers exhibit a higher proportion of slow-twitch fibres and prefer to skate long-distance races. However, the majority of the association between muscle fibre type and PRD was independent of ACTN3 genotype. In conclusion, the ACTN3 R577X polymorphism is associated with preferred racing distance in speed skaters and muscle fibre type composition. Thus, it is probably partly via associations with fibre type that the R577X polymorphism contributes to a small but perhaps important component of the ability to perform at a high level in speed skating.