Question

fill in the blank question muscle fibers that have an abundant blood supply, many myoglobin molecules and mitochondria, and are adapted for exercises like walking, jogging and biking, are known as twitch fibers.

Explanation:

Muscle fibers with an abundant blood - supply, many myoglobin molecules and mitochondria, adapted for endurance activities like walking, jogging and biking are slow - twitch fibers. Slow - twitch fibers rely on aerobic respiration and are fatigue - resistant.

Answer:

slow