I find that my body is Always relaxed, whereas my mind is Always restless.
It is not easy to overcome such restlessness. As Steve implies, I heard many reasonable hypotheses for the causes of restlessnes but I heard no really effective methods to get rid of such mental state.
Usually we are told that to have an active mind is good. However this business of an active mind does not help us during meditation. I believe we have to look at the topics of conversation and the issues we allow ourselves to entertain our minds with daily to begin to see where this source of restlessness originates. I think I allow myself to go on and on about some subjects and about some past experiences that serve no constructive purpose and there is little i can do to change or rectify them. The best course of action is to clear my thoughts of such useless information and raise my consciousness to higher levels of awareness in meditation so I am more effective when and if I have to face daily issues.