Final answer:
Higher compression ratios refer to the abundance of slow-twitch muscle fibers in marathon runners, which results in increased endurance. Frequent running can improve these physical traits, and technology like compression suits can further enhance performance by decreasing drag.
Step-by-step explanation:
Higher compression ratios in the context of muscle fiber composition are akin to the physical traits that benefit a marathon runner. Marathon runners are likely to have a high proportion of slow-twitch muscle fibers (SO fibers), which contribute to greater endurance over long distances. This is in contrast to fast-twitch fibers (FO and FG fibers) which are more suited for quick bursts of speed and power but less so for endurance. A marathon runner benefits from this higher ratio of SO fibers, as it allows them to maintain speed and endurance over the lengthy course of a race.
In terms of running performance and natural selection, frequent running can lead to beneficial adaptations, such as improved endurance and potentially running speed. For example, runners with a high percentile for speed in a race are faster compared to their peers, indicating that they can maintain higher speeds during competitions. Moreover, technology like compression suits can aid performance by reducing drag, as seen in swimming where bodysuits provide significant reductions in drag forces.