The latest research shows that the optimal range to build muscle looks like the following: Reps: Anywhere from 5 - 30 although 8 - 15 is probably the best Sets: Between 10 - 20 sets per muscle per week. You can split those sets up over multiple workouts. So 5 sets twice per week, or 3 - 4 sets 3 times per week. Having said that a beginner will build muscle doing far less sets than that. Perhaps as little as 3 sets per week... Individual results will vary. The approach that I use with my clients is to start with as little as possible to get results. Only if they need more sets do I have them add more.