Grit by Angela Duckworth (https://www.amazon.com/Grit-Passion-Perseverance-Angela-Duck...) goes into deliberate practice quite a bit.

She talks about how deliberate practice is almost never enjoyable because you're trying to improve specific things, but it is how you attain mastery. The other side is "flow", when that mastery is display, and she mentions how it can look so effortless for top athletes, when it's almost definitely the result of hours and hours of deliberate practice.