Author/Editor		Lindholm, A
Title		Training effects on skeletal muscle in horses
Type		članek
Source		In: Cestnik V, Pogačnik A, editors. Referati 6. Zavrnikovega spominskega sestanka; 1995 nov 9-11; Lipica. Ljubljana: Veterinarska fakulteta,
Publication year		1997
Volume		str. 65-70
Language		eng
Abstract		Skeletal muscle is composed of fibre types with different metabolic and histochemical properties. The biopsy technique is important for obtaining relevant muscle samples. The type I and IIA fibres have a high oxidative capacity whereas type IIB fibres have a lower oxidative capacity. In Standardbreds trained from 18 months of age type IIA/IIB fibre ratio and the citrate synthase (CS) activity increases in the muscle. When training started after three years of age these effects on type IIA/IIB fibre ratio or CS were not seen. An increased capillary supply adjacent to the fast twitch fibres was observed in Standardbreds and Thoroughbreds that underwent 5 and 6 weeks of treadmill training, respectively. During 6 weeks of detraining capillary density decreased in the Thoroughbreds but not in the Standardbreds. The type IIB fibre area decreased with training in Standardbred horses. With draught loaded exercise in Standardbred horses all fibre types are recruited at a low trotting speed and a rapid increase in type IIA/IIB fibre ratio, type IIA fibre area and CS activity was seen already after two weeks of strength training. It is obvious that fibre type proportions, capillary supply, oxidative enzyme capacity and fibre size are related to the state and type of training and performance ability of the horse.
Descriptors		MUSCLE FIBERS, FAST-TWITCH MUSCLE FIBERS, SLOW-TWITCH PHYSICAL EDUCATION AND TRAINING HORSES