Gym shakers, also known as protein shakers or blender bottles, are portable containers designed for mixing and carrying nutritional supplements like protein shakes, pre-workouts, or BCAAs. Typically made of durable plastic, they feature a secure lid, a mixing mechanism such as a wire whisk or a blender ball, and measurement markings for precise dosing. Gym shakers facilitate quick and convenient preparation of supplements, allowing athletes to refuel and recover effectively before, during, or after workouts. They're a staple accessory for fitness enthusiasts, bodybuilders, and athletes, offering a convenient way to maintain proper nutrition and hydration while on the go.