There is no such position as Mayor of the United States (US). A  Mayor is typically a political position for cities and towns. The  United States is led by a president. Curr â¦ ently, the president is  Barack Obama.
Slow twitch muscle fibres are good for endurance activities like long distance running or cycling. They can work for a long time without getting tired. Fast twitch muscles are good for rapid movements like jumping to catch a ball or sprinting for the bus.
They are different type of muscle fibres (US spelling Fibers). Fast twitch are good at contracting fast but fatigue quickly. Slow twitch contract more slowly but do not fatigu â¦ e as fast.In athletes, sprinters tend to have a dominance of slow twitch fibres while insurance competitors have a dominance of slow twitch.hey are different type of muscle fibres (US spelling Fibers). Fast twitch are good at contracting fast but fatigue quickly. Slow twitch contract more slowly but do not fatigu â¦ e as fast.