Practice makes us perform better, right? It's how we learn, how we improve, and how we maintain the skills we have already acquired. So, beginners often assume that the amount of time they spend practicing is proportional to how quickly they will progress. To a point, this is true. However, there is also such a thing as too much practice, and it's a lot less than beginners typically assume.
I see a lot of posts in social media from beginners who are claiming to practice for a very ambitious, overzealous amount of time. I heard such things from beginners when I was a student, too. Some of these claims are likely exaggerated. You won't have much of a life apart from the violin if you are practicing for several hours every day. No time for a social life or other responsibilities. But in case there is truth to such claims at least some of the time, I tell my own students, as I am about to explain below, that mindless, excessive practice will actually hurt more than it can help.
Practice must be focused and deliberate to be beneficial. If your practice exceeds your attention span, or if you are hungry or thirsty or uncomfortable from standing for so long, you aren't going to be focused, and you might develop bad habits and make more mistakes due to fatigue. Repeating things develops muscle memory, whether or not you are repeating them correctly. Practicing too much can actually cause you to regress.
Quality is so much more important than quantity that there really isn't even a good reason to watch the clock apart from making sure that you aren't late for something else you have scheduled. If you time your sessions, you might end up wasting time looking at the clock. Some students, especially children, may feel like they're being punished if they are conditioned to associate timers with "time out." It's better to have a structured practice routine and to simply be done when you are done.
Furthermore, it's best to not be concerned with how quickly you are learning. All musicians go through