Muscle Gain, Rest, and Stimulation As part of your shoulder training, perform shrugs. According to a research published in the March 2003 edition of "Medicine and Science in Sports and Medicine," if you are a novice, you should train each muscle group three times per week and twice per week if you are an expert exerciser. Shrugs can be done either alone or with weights. When you shrug, all muscles involved in the movement must work together in harmony for it to be effective. Thus, multiple sets of 10-12 repetitions is appropriate for most people. The study also noted that increased stimulation from repeated activity helps muscles grow. So, by performing shrugs frequently, you will increase the size of your shoulders over time. You should feel your shoulder blades pull back when you shrug. This is normal activity for these muscles and they should not hurt when you shrug. However, if you experience pain when doing so, stop immediately. Follow up with more specific shoulder exercises instead until you reach maximum improvement.