A protein shake is basically a means of ingesting protein as part of your diet. It is typically a mix of protein powder and water, or milk, or some form of liquid. Many people add fruit, oats, etc to increase calories or ingest other nutrients.
Bodybuilders and atheletes in general use it as a means to quickly and rapidly absorb protein into their body to aid in muscle development.
The cost depends on what kind you buy. It ranges between $18 - $38
