When doing crunches to build abdominal muscle it is important to keep your neck protected. When doing crunches a great perfect amino reviews way to protect your neck is to push your tongue up against the roof of the mouth. This will help you to align your head and reduce the amount of strain you put on your neck. Working out to build muscle is most efficient if you focus on large muscle groups. These include the back, legs, and chest. Implementing workouts that focus on these groups will do the most work in the shortest amount of time, meaning that you'll grow muscle more quickly and easily than with other workouts.