Muscle twitching is simply tweaked out muscles or tension. Mine do that alot. If you were overtraining, you would be constantly fatigued, sleepy, get sick easily, diminished results, etc. You will know when you are overtraining, but HARD training can seem like you are over-doing it. I used to work out soo hard my back would sharply spasm during the night so that it felt like I was going to break. Full body cramps, yada yada. That stuff just comes with the territory of hard training.
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