Growth-related change in specific force but not in specific power of rat fast skeletal muscle.
The effect of growth on the dynamic performance of rat medial gastrocnemius muscle was studied. From approximately 1.5 to 5 months of age specific force increased by 18%. Reductions were found in both optimal stimulation frequency (from 120 to 100 Hz) and optimal shortening velocity (by 16%) indicating that the fibres became slower. Specific power did not change during growth but was obtained at a lower shortening velocity. Possible mechanisms for the observed changes are discussed.
de Haan
A
A
Department of Muscle and Exercise Physiology, Faculty of Human Movement Sciences, Vrije Universiteit, Amsterdam, The Netherlands.
de Ruiter
C J
CJ
Lind
A
A
Sargeant
A J
AJ
D000375:Aging / Q000502:physiology*; D000818:Animals; D007537:Isometric Contraction / Q000502:physiology*; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D024510:Muscle Development; D009132:Muscles / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains