I know salmon and avocado are good for us, but are they good protein sources? Do they build muscle? Are there any other advantages to these two foods?

Salmon is high in protein, high in vitamin D and is considered an 'oily fish' because it is high in Omega 3 fatty acids. Avocados are high in mono-unsaturated fat and loaded with vitamins, minerals and antioxidants. Avocados are high in fiber and have a slow release of energy  so they are very good for athletes.  Avocados and salmon are great foods to eat if you wish to fuel your body. The other advantage these two foods have is they are good, clean sources of healthy fats, protein, carbohydrates and fiber. Salmon, avocado, leafy green vegetables, colored peppers and other colorful fruits and vegetables in a salad will provide a person with all the nutrition we need.

To build muscle you need to lift weights to the point of muscle fatigue. If you simply consume these foods but do not engage in weight training, you will put on pounds in the form of fat, not in the form of lean muscle.