Muscle

The anaerobic energy delivery system uses predominantly Type II or fast-twitch muscle fibers, relies mainly on ATP or glucose for fuel, consumes relatively little oxygen, protein and fat, produces large amounts of lactic acid and can not be sustained for as long a period as aerobic exercise. As the antagonist for this motion, the triceps brachii muscle extends the arm at the elbow. Myosin proteins act like oars on a boat, pulling the thin filaments closer to the center of a sarcomere.

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