I am strong, energized and full of vitality.

Vitality is mostly produced rather than stored. The walk you least want to take at six in the evening is the one that hands energy back within about ten minutes, which is an irritating fact and a dependable one.

Sitting still and waiting to feel up to it is the arrangement that never resolves. The body is not holding anything in reserve for you. It is idling, and idling costs very nearly as much as moving.