Effort refers to the work put into something. If you do not put forth your best effort then you are more likely to fail in achieving your goals, but if you give something all of your efforts then you have accomplished much even if the end goal is not met. The effort required to move a 5 lb block is far less than the effort needed to move a 500 lb block.
But the effort, the effort! And as the marrow is eaten out of a man's bones and the soul out of his belly, contending with the strange rapacity of savage life, the lower stage of creation, he cannot make the effort any more