Ultra Boost Force A key when training for muscle growth is to incrementally increase the volume of your training. That means that, as the weeks and months go by, your workouts should get longer. To make this happen you should vary the volume of your sets. Lightening the weight a little and doing between 10 and 20 reps on an exercise every now and then is a great way to spark new muscle tissue growth. The more total volume of training you can achieve in a workout the better. But make sure that you improve your volume incrementally. Don't double your training volume overnight, or you will over-train.