Final answer:
The statement that world-class gymnasts and figure skaters would have a fast firing frequency is correct, as it enables stronger muscle contractions crucial for their sports. This is related to the proportion of fast-twitch muscle fibers which are more prevalent in athletes engaged in explosive, short-duration activities.
Step-by-step explanation:
The significance of the firing frequency of motor units is critical in athletes like world-class gymnasts and figure skaters, who are suggested to have a fast firing frequency. This is because rapid firing of motor units can lead to stronger muscle contractions and more powerful, precise movements which are essential in sports that require bursts of strength and finesse.
A high firing frequency can lead to what is known as incomplete tetanus, where muscle tension increases significantly as a result of quick cycles of contraction with a short relaxation phase. If the frequency is very high, this can lead to complete tetanus, where contractions become continuous. Different types of muscle fibers also play a role in this. Professional sprinters, for instance, are most likely to have a higher proportion of fast-twitch muscle fibers—like 80 percent fast-twitch muscle fibers and 20 percent slow-twitch muscle fibers —which are more suited for explosive, short-duration activities. World-class gymnasts and figure skaters would similarly benefit from a higher proportion of fast-twitch fibers and a fast firing frequency due to the explosive nature of their sports.
It is important to note that not all people have the same proportion of slow-twitch to fast-twitch muscle fibers; this proportion can vary greatly between individuals, affecting their potential for various physical activities.