There are some skills that take a lot of time to learn because feedback is delayed. Examples I have in mind are weightlifting, healthy eating, and mindfulness. The promised effects of practicing these skills are realized after only much time has been spent. This makes the efficiency of one's effort very difficult to see. It is difficult to learn what are the best ways to practice these skills to the best effect.
What general research is there on how to optimally learn in a delayed feedback environment?
More generally, I guess I am asking how people respond to Sorites paradox, also called the sand pile paradox, and how they might psychologically get past it. The sand pile paradox is occurs when you think about removing a grain of sand from a sand pile one at a time. If you have a pile of sand, removing a grain from it will not change it from being a pile a sand. Yet we know the number of grains of sand is finite so eventually all the grains will be removed. In other words, how to large changes from small changes over long periods of time?
I am looking for studies that speak to this.