Slow Release Protein helps provide Amino Acids to the body over an extended period of time. This ensures your muscles remain adequately fed hours after a workout. Extended Release Proteins like Micellar Casein are most beneficial before going long periods of time without consuming Protein, like before you go to bed. Consumption at these times ensures your body isn't starved of nutrients and therefore helps prevent muscle breakdown and increases recovery. Using an Extended Release Protein will also keep you fuller for longer making them perfect as a meal replacement shake.