Beast Factor Extend It is always a temptation to work your reps in each set as quickly as you can, but don't let yourself do it. Slower repetitions of the exercises yield better results. Don't be afraid to trade off for a lighter weight in order to accomplish more reps. A fine goal is to spend five to ten seconds on each movement half, for a total of twenty seconds per repetition. When you start strength training, make sure you have good form first. The slightest mistake in a rep can cause you to perform the exercise more and more incorrectly as you increase the weight. Neglecting your form will lead to injuries later on.