General Preparedness

CrossFit (constantly varied, high intensity, functional movements) approaches fitness as general physical preparedness. So, you are as fit as you are generally prepared to handle any and all contingencies within your physical capacity.

Strength - ability of muscles to apply force
Power - ability of muscles to apply maximum force in minimum time

Endurance - ability to gather, process, and deliver oxygen
Stamina - ability to process, deliver, store, and utilize energy

Flexibility - ability to maximize range of motion at joints
Coordination - ability to combine distinct individual movement patterns into a single distinct pattern

Balance - ability to control center of gravity in relation to support base
Accuracy - ability to control movement in a given direction at a given intensity

Speed - ability to minimize the time between repeated movements
Agility - ability to minimize transition time between movement patterns

The total capacity in these ten abilities averages to how fit you are physically: your work capacity across broad time and modal domains.

It will also determine which things will be easier to face and which will be harder to face.
The challenge: find the things that will be hard to face and face them in training.
When things playing to your strength come up, it will be like a fun day.
By constantly varying functional movements, there will be plenty of opportunity to work on these areas.

This attitude of training toward the things that seem hard when we might say, "anything but that," translates to every area of our lives. How do we love our spouse, kids, neighbors, or enemies if we don't have that attitude. It might be the hard thing to do and we could do something else. In the end, we want to be generally prepared for all contingencies within whatever capacities we have.