Final answer:
Local muscles consist mainly of Type I (slow-twitch) fibers which are adapted for endurance activities due to their ability to generate energy through aerobic metabolism.
Step-by-step explanation:
Local muscles are composed predominantly of Type I (slow-twitch) fibers. These muscle fibers are characterized by their high density of capillaries, plentiful mitochondria, and rich content of myoglobin, giving them a red appearance.
Slow-twitch fibers are mainly responsible for endurance activities such as long-distance running because they use aerobic metabolism to produce ATP, allowing the muscle to sustain activity over long periods without fatigue.