slow-twitch fiber


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slow-twitch (ST) fiber

a muscle fiber that develops less tension more slowly than a fast-twitch fiber. The ST fiber is usually fatigue resistant and has adequate oxygen and enzyme activity. Studies indicate that world-class endurance runners apparently have high percentages of ST fibers. It is called red muscle because of the abundance of capillaries serving the fiber muscle. The muscle also contains high amounts of the protein myoglobin that functions to store oxygen inside the muscle cell. See also fast-twitch fiber.
References in periodicals archive ?
The percentage of slow-twitch fibers was positively correlated with grilling loss, whereas an inverse relation between percentage of fast-twitch fibers was observed.
To compare the present results to previous studies, slow-twitch fibers are assumed as slow-twitch oxidative (SO), type I, [beta] red or red fibers, respectively, and fast-twitch fibers as fast-twitch oxidative glycolytic (FOG) and fast-twitch glycolytic (FG) (Peter et al.
For example, it is quite possible to lift a relatively light object very quickly, with low intensity, and activate only slow-twitch fibers.
The contribution of the slow-twitch fibers decreases across the work cycles, thus depressing the starting and ending points of the available force.
In short, given that the observed decrement in available strength is relatively small and the duration of the MVC is itself relatively short, the equation we use to model this change (Equation 7) would have predicted much the same curve had we assumed the existence of a decreasing proportion of slow-twitch fibers contributing to the overall available force in the model of Deeb et al.
Slow-twitch fibers are fueled by aerobic respiration, a chemical reaction that relies on oxygen.
Type I fibers are slow-twitch fibers, and they are built for fatigue resistance.
Additionally, it has been previously reported that adaptations in muscle fibers of muscles comprised of primarily slow-twitch fibers (such as the soleus) occur at lower exercise intensities, whereas adaptations in fast-twitch muscle fibers increase dramatically at higher intensities (Dudley et al.
The loss of slow-twitch fibers that take up glucose in response to insulin is relevant to the high prevalence of insulin resistance in stroke survivors [13].
One research team had suggested a genetic component when it found an "unexpectedly high" number of slow-twitch fibers in the untrained muscle of certain endurance athletes.
Acid buildup caused the non-athletes' performance to decline by tiring their muscles, which had too few slow-twitch fibers to sustain the previous level of force, Park says.
Skeletal muscles are a mix of slow-twitch fibers, designed to resist fatigue, and fast-twitch fibers, which enable intense periods of work.