Sprint‐training effects on some contractile properties of single skinned human muscle fibres

Abstract

The effects of sprint training on the contractile properties of human muscle fibres obtained by needle biopsy were investigated. Individual fibres were mechanically skinned and activated by Ca2+‐ and Sr2+‐buffered solutions at pH 7.1, and allocated to distinct populations on the basis of their contractile characteristics. The majority of fibres sampled pre‐training could be separated into the three major fibre groups: Populations I (24/70, 34%), II (25/70, 36%) and III (18/70, 26%), which exhibited characteristics similar to those of histochemically classified type I, IIA and IIB fibres, respectively. The remainder (3/70, 4%) represented another fibre group, with intermediate characteristics..