Final answer:
Different energy systems are used during a 3-minute boxing round: the Phosphagen System for the first punch, the Anaerobic System for a continuous flurry of actions, and the Aerobic System during rest periods for recovery.
Step-by-step explanation:
During a 3-minute boxing round, different energy systems are used to fuel the body's activities. At the start of the round, the Phosphagen System is the predominant system used for delivering energy for the first punch due to its ability to provide quick bursts of energy. Specifically, creatine phosphate can generate the ATP needed for about 8-10 seconds of high-intensity activity like a single punch.
When a boxer engages in a continuous flurry of jabs and fast moves for about 30 seconds into the round, the Anaerobic System takes over. This system utilizes glycogen to make ATP from glucose without the need for oxygen, fitting for intense activities lasting up to 90 seconds.
In the last 30 seconds of the round, while the boxer moves around the ring more moderately, the body continues to use the Anaerobic System, although energy demands might be starting to shift towards the Aerobic System as the activity becomes less intense.
While the boxer is sitting on the stool during the 1-minute rest between rounds, the Aerobic System becomes the primary energy source. This system can supply ATP for several hours or longer using oxygen to break down glucose—ideal for recovery periods and moderate activity.