SPRINT PERFORMANCE IS RELATED TO MUSCLE FASCICLE LENGTH IN MALE 100M SPRINTERS

Abstract

1652 Although it is known that muscle fiber length plays a significant role in determining maximal shortening velocity, it is unknown whether there is a relationship between muscle fiber length and sprint performance. The purpose of this study was to investigate the relationship between muscle fascicle length (FASL) and sprint performance in 33 college male 100m sprinters (5-9 years of professional experience). The sample was divided into two performance groups by best 100m sprint time; 10.3-10.9 sec (G10S) and 11.0-11.8 sec (G11S). Fascicle pennation angle (PANG) and isolated muscle thickness (MTH) of the vastus lateralis (VL) and gastrocnemius medialis (MG) and lateralis (LG) muscles were measured in vivo by B-mode ultrasound, and FASL was estimated. Standing height, body weight, and upper and lower limb lengths were similar between the groups. Isolated MTH was similar in G10S and G11S for VL (2.76±0.32 and 2.63±0.32 cm, respectively) and MG (2.37±0.36 and 2.22±0.22 cm), but G10S had a significantly greater LG MTH (1.94±0.24 and 1.70±0.21 cm). PANG was greater in G11S for VL muscle (19.4±3.1 and 21.6±2.7 deg, respectively), but was similar between groups for MG (21.4±3.0 and 22.9±2.5 deg) and LG (14.1±1.5 and 14.9±1.8 deg). In all muscles, G10S (VL; 8.4±1.3, MG; 6.6±1.5, LG; 8.1±1.7 cm) had a significantly greater FASL than G11S (VL; 7.2±1.2, MG; 5.7±0.6, LG; 6.6±0.6 cm). There was a significant correlation between FASL of the VL (r=−0.36, p<0.05), MG (r=−0.40, p<0.05), and LG (r=−0.55, p<0.01) muscles and 100m performance time. In conclusion, there appears to be a relationship between FASL of muscles involved in sprinting in 100m sprint specialists.