QUOTE(califb @ Jul 19 2006, 07:11 PM)

I think their great speed and agility is probably related to not only their great strength due to increased muscle mass, but also by the total number of the type of muscles they have (fast twitch vs. slow). Also to have great agility and coordination they must be able to instantly balance the entire body by precisely controlling the movement and non movement of each individual muscle (think ballet dancer, mountain goat ). It is also very possible that their coxal joint (hip) allows them a greater range and efficiency of stride over that of a human being, and a greater flexibility of the spine and articulations of the lower legs allows for more "spring" when running and jumping. Combine these with most certainly a much greater lung capacity, a larger heart, a more efficient respiratory system for getting an increased amount of oxygen to the muscles, and excellent night vision and you have a super quick and stealthy athlete who can also kick some serious butt... I bet Uncle Sam would like to have a few of these guys to send to Iraq...
Califb,
You and Roadrunner gave us, what I consider, some very precise and excellent explainations for their speed. Both advised that their speed could be attributed to their massive muscle structure. I guess they must also have a massive bone structure.
But in humans, a massive muscle structure would have a tendency to reduce speed and fatigue more easily. Am I correct in that ..... or do not quite understand the relation of massive muscle and speed???
As far as their speed, which animal that we know would come closer to matching it???? African Lion??? Brown Bear???