Amino acid tablets can be substituted for a protein shake in the post-workout recovery period. However, a protein shake is a more convenient form for ingesting amino acids, because a large number of tablets would have to be swallowed to equal the protein content of one shake, according to About.com.
After a workout, consuming protein and carbohydrates together can enhance recovery, as was shown in a study published in 2006 in Medicine & Science in Sports & Exercise. According to About.com, a person can replace a post-exercise protein shake with amino acid tablets, but would have to take a lot of the tablets to equal the same amount of each amino acid that is present in any of the complete protein shakes. Another benefit of consuming a protein shake rather than multiple handfuls of pills is that the water content of the shake can help replenish the water lost from sweating during the workout.