I feel that "sparring" is actually an "examination" of "what you know" and your ability to apply that knowledge. It also includes a player's physical condition as well as mental strength and stability.
Hence, trainings should be more focused instead of purely playing with different opponents everyday.
Example, if you want to train opening, you do research on a particular topic and conclude whatever you had learnt. If you want to train midgame, you can look at those midgames of china masters and think of what you are going to move if you are the masters. For end games, you can train by learning those "ding shi".