If there were a single rhythm to describe the Universe, I believe that rhythm would be ‘cycles’. Nothing is every stationary, and not just that, nothing ever moves in a single direction for too long. There is always an ebb and flow, a season to everything.
What that means to me is that there isn't much point in fighting the season; you are better off going with the flow. If it is winter and the weather outside is freezing, don't think too much about staying home, conserving your energy and stepping out another day.
When things seem to be going well, act forcefully and do as much as you can, because (perhaps) Lady Luck is on your side. When things don't seem to be going well, call it a day and go to bed - tomorrow is another day.