HMS, BM 2019 HSC 17 MC

The graph shows the relationship between an athlete’s running time and the contribution of three energy systems.

Which of the following shows the by-product and rate of recovery following exhaustion for the dominant energy system at 50 seconds running time?

Show Answers Only

\(D\)

Show Worked Solution

D is correct: At 50 seconds, lactic acid system dominates producing lactic acid with long recovery.

Other Options:

A is incorrect: Carbon dioxide is aerobic system by-product, not dominant at 50 seconds.
B is incorrect: Carbon dioxide with short recovery describes ATP-PCr system characteristics.
C is incorrect: Lactic acid system recovery takes much longer than 5-20 minutes.

♦♦♦ Mean mark 41%.