Yes, there is such a thing as too much practice. Perfect or good practice helps you learn skills. Practicing or repeating a skill the wrong way doesn’t help because you’re learning the skill incorrectly. If you practice for too long all at once, you can become fatigued, and your good practice turns into bad practice. When you get tired, you start to make mistakes, and that makes your practice ineffective. Also, if you get bored with practice, you might start to practice a skill incorrectly.
This doesn’t mean that you should always stop practicing when you get tired. During a game, you often have to perform skills when you’re tired. For example, late in a basketball game, you might have to shoot when you’re tired. So practicing shooting when you’re a bit tired can help you shoot well in a game when you’re tired.
The important thing to remember is to focus on good practice when you start to get tired or bored. If the practice is not good practice, find a way to practice correctly or stop the practice until you can concentrate better. Practicing one skill for a while and then another for a while can help you keep from getting bored and can help you practice well, even when you’re tired. However, if you’re too tired to practice properly, stop your practice and try again at another time.