What means to be relaxed in Martial Arts?

People consider being relaxed when they are taking a nap or letting all the energy from their movements die out. It seems to be very difficult to find a state of being actively relaxed. In Martial Arts that is the dominant state of being. We can not be all bumped up all the time, nor can we be indifferent and loose. By choosing either one of those we narrow down our choices. Stiff power is slower and lacks reaction time, being too relaxed slows us down and techniques can not connect to the power source. 

Being actively relaxed is being alert. Not afraid and jumpy, because being afraid makes our body tense up. Alert is being aware and focused. Think of a cat. Cats tend to be fully aware of their surroundings at all times. They can be very relaxed, even sleep, but still react unbelievably fast. Now I want you to think of a cat or a dog that is ready to do something fun and is really ready to go. There is a state of alertness we should have in competitive situations - it is still relaxed, but attentive. Then think of a dog waiting for the owner to come home in safe surroundings feeling sleepy and resting. Then at the exact moment when the dog hears keys in a lock and someone is coming home - oh boy, the dog is ready and the alert level goes up. As people, we are much slower. But the change in alertness should be worked on. Once we find different states of being alert, we find active relaxation and faster reactions. Also, movements will change when we find active relaxedness - everything comes more natural and easy.