They must go hand in hand.
No point reading a book or doing a course if you do not put your learnings into practice.
Theory is just that until you implement and test for yourself.
Otherwise we would all be fit, healthy, young for our age with the agile mind of a rocket scientist.
Worse still, trying something new for a minute before moving onto the next shiny thing.
Never satisfied and always disappointed.
Growth takes practice, discipline and above all patience, the opposite of the distracted world around us.