Active muscle and tendon stiffness of plantar flexors in sprinters

The aim of the present study was to investigate and compare muscle and tendon stiffness under active conditions in sprinters and untrained participants. In total, 14 sprinters and 24 untrained men participated in this study. Active muscle stiffness in the medial gastrocnemius muscle was calculated based on changes in estimated muscle force and fascicle length during fast stretching after submaximal isometric contractions. Tendon stiffness was determined during isometric plantar flexion using ultrasonography. No significant differences were observed in active muscle stiffness between sprinters and untrained men at any torque levels. Furthermore, no significant difference was noted in tendon stiffness between the two groups. These results suggest that muscle and tendon mechanical properties in the plantar flexors under active conditions are similar in sprinters and untrained participants.     

Association between COMT Val158Met polymorphism and competition results of competitive swimmers

Recent studies have shown the contribution of genetic determinants to athletes’ physical ability. However, despite the fact that cognitive abilities like self-control and stress-tolerance influence athletes’ competitive performance, few studies to date have investigated the association between genetic polymorphism, which is linked to cognitive ability and athletic performance. The present study investigated the link between single-nucleotide polymorphisms (SNPs), which are known to exert influences on dopaminergic neural function and competitive performance of swimmers. The results have revealed superior competitive performance in competitive swimmers with Met allele of catechol-O-methyltransferase Val158Met polymorphism than those with Val/Val genotype. The investigated SNPs of DRD2 and DRD3 were not associated with swimmer’s competitive performance. This finding indicates that genetic polymorphism linked to cognitive ability influences the athletes’ performance.