Histochemical and functional parameters in Nordic combination athletes

Bioptic samples from the vastus lateralis muscle were analyzed in a group of Czechoslovak representatives in the Nordic combination (ski-jumping and 15 km cross-country skiing). The distribution of individual muscle fibre types (FG, FOG and SO) was detected and correlated with values obtained by motor and functional performance tests. Histochemical analysis of the bioptic samples revealed a considerably heterogeneous distribution of muscle fibre types in the group studied. No typical profilation for this sport discipline was found. Weak correlation between the proportion of fast muscle fibres and explosive strength parameters was ascertained. The correlation between the proportion of slow muscle fibres and the capacity of O2 utilization (VO2max) was statistically significant. Strong correlation between the proportion of fast twitch fibres and relative maximal strength of knee extensors (N/kg) was disclosed. A non-linear relation between the area of fast twitch fibres and vigour of take-off was found.