Some people are unable to persist for very long precisely because they’re trying so hard to do it. Persistence is not about trying. Persistence is about continuing to be effective, and that comes from striking a healthy balance between effort and rest.
Life is a cycle of effort and rest. The effectiveness of each depends on the other. You cannot cheat this cycle. Sleep all night and day and you’ll feel awful. Work (or play) all day and night and you’ll be worthless the next day.
Maximum effectiveness requires balance. You’ve got to work diligently, and you’ve got to regularly stop along the way to rest and relax. Sometimes you can be more effective in your work by doing less of it. Sometimes you can get a better rest when you work a little harder. Balance is crucial.
Persistence is a long-term endeavor. Nothing of value is created in a one-shot effort. Try to do it all at once, with no stopping to rest in between, and you’ll end up with a lot of activity but not much accomplishment.
It may seem strange to say that persistence depends on regularly taking time off, yet when you really think about it that’s the way the world actually works. Look at how much sleep babies get, and then consider how quickly they grow and develop. Rest and relaxation are essential to persistence. Being tired all the time is no way to develop persistence. Being rested and full of energy is much more effective.