It grows up to 12 feet tall in USDA zones 5 through 9. Another shrub, called the wayfaringtree viburnum (Viburnum lantana Mohican), grows 7 or 8 feet tall, blooms for three weeks in May and produces orange-red berries in July that ripen to black near summer's end. It grows in USDA zones 4 through 8.
fast-twitch (FT) fiber. a muscle fiber that can develop high tension rapidly. It is usually innervated by a single alpha neuron and has low fatigue resistance, low capillary density, low levels of aerobic enzymes, and low oxygen availability. FT fibers are used in such activities as sprinting, jumping, and weight-lifting.
Fibers can also be classified on their twitch capabilities, into fast and slow twitch. These traits largely, but not completely, overlap the classifications based on color, ATPase, or MHC. Some authors define a fast twitch fiber as one in which the myosin can split ATP very quickly.