Repetition is the mother of learning. We are what we repeatedly do. I doubt anyone would argue with those points. The task then becomes to carefully chose what we repeat. It is necessary to have a clear idea of the technical model you wish to achieve and a plan to achieve the desired technique. It is very important to fit the technique to the person not the person to the technique.
Also, more is not better. Bernstein’s concept of “repetition without repetition” is crucial – essentially variation and distributed practice is the key to deep sticky learning not hours of mindless repetition of the same task . Quality is the goal and quality is a measure of perfect. Therefore, the ultimate goal of repetition in training is mastery. To achieve mastery demands progression, from easy to hard and simple to complex.