A tree does not grow to its full, magnificent height in a single season. Rather, it grows for a few months, sheds all its leaves, and becomes temporarily dormant. After a period of rest, the tree sprouts a whole new set of leaves and begins to grow upward again.
Life is a cycle of effort and rest.
The effectiveness of each depends on the other. Get enough rest, and you'll be more effective in your efforts. Put your energy into your actions, and you'll rest well. Going, going, going all the time will not get you where you truly desire to be. Move steadily and forcefully forward.