Casein protein is known as "night time" protein because unlike it's sister whey protein, casein can take up to 7 hours to be digested and used by the body. You might be thinking that's exactly what you don't what, slow digesting protein! But for the night time, before you sleep, that's exactly what you do want.
The majority of muscle repair and regrowth happens while you're fast asleep! While you're asleep your body is taking the opportunity to recover from your intense training sessions. Casein is ideal before bed because it gives the body a constant, slow release supply of protein for use throughout the night.
Casein can also be used throughout the day in your home made meal replacement shakes! Meal replacements don't need to be absorbed fast, so that makes casein protein ideal.