Protein shakes are beverages made by mixing protein powder with water, milk, or other liquids. They are popular among athletes and fitness enthusiasts because they help build and repair muscles after workouts. Many people also use protein shakes as a convenient meal replacement or snack, especially when they are on the go. These shakes come in various flavors and can include additional ingredients like fruits, vegetables, or nut butter for extra nutrition. Some common types of protein used in shakes are whey, casein, and plant-based proteins like pea or soy. Overall, protein shakes are a quick and easy way to boost your protein intake.