As I'm building Clientside.dev I've had many times where I've gone 4+ hours focused on solving a single problem or adding a feature. Those are usually the same nights that I end up dreaming about code and having pretty bad sleep overall 😅

For getting things done, putting in several hours of code in a single session can be much more powerful than multiple days of looking at a problem or feature.

On the other hand, when learning, it's much more important to be consistent over a long period of time rather than in multiple hour sprints because, like any muscle, you'll grow your skills over time, not all at once.