If you have never heard of it, it might be one the most important things to remember while training.
Visualize the muscles you are training. If you don’t know what muscles you are working, then you have bigger problems.
I guarantee that if you use your mind to hone in on the muscles in play, you will feel them working.
Don’t just pull and tug stuff while you are working out. Form is also very important, or you will be working muscles that are not your target. This could cause strain, premature tiredness, and ineffectual training.
If you have no clue what you are doing, ask for help to avoid injury and maximize your workout.