Strength
–noun

1. the quality or state of being strong; bodily or muscular power; vigor.
2. mental power, force, or vigor.
3. moral power, firmness, or courage.

Endurance
-noun

1. the fact or power of enduring or bearing pain, hardships, etc.
2. the ability or strength to continue or last, especially despite fatigue, stress, or other adverse conditions; stamina.
3. lasting quality; duration.

Flexibility
–adjective

1. capable of being bent, usually without breaking; easily bent.
2. susceptible of modification or adaptation; adaptable.
3. willing or disposed to yield; pliable.