Your just finished an intense, grueling workout. You want to refuel as quickly as you can, and get some protein for your repairing muscles.

You reach for a powder, mix it with water, and chug a protein shake. Chances are, that was whey protein.

Whey is the standard and most-used protein for supplementation. There’s a simple reason for that – whey is the most easily and quickly digestible protein. Drinking a whey protein shake will rapidly deliver protein and amino acids into your system, to be immediately put to use rebuilding your muscles.

But what is whey? And what else is there?

Whey is the byproduct of the cheese-making process, the liquid left over after cheese is formed.  Before whey came into widespread use as a protein supplement, it was either discarded or used for animal feed. Now that it’s in cabinets everywhere in powder form for a post-workout boost, it’s a $5 Billion global industry.

Casein is whey’s counterpart

We said whey is the liquid byproduct of cheese-making, the waste. Casein is the protein that bind together to form the cheese, so it’s slightly more expensive.

Whey and casein both contain all nine essential amino acids, and they are actually more rapidly absorbed by your body than the amino acids in the foods you eat.

We mentioned that whey sends nutrients shooting to your muscles immediately. This is one of the wonderful benefits of whey protein, but it is also a downside. As quickly as it gets to work, it’s used up soon after.

Casein, on the other hand, is digested and absorbed at a much slower rate, breaking down and being absorbed by the body over a 6-8 hour period. For this reason, it’s widely recommended for a bedtime protein shake, to keep your body supplied all through the night.

So what happens when you combine a slow and a fast-digesting protein? It’s a thing of beauty:

Adding casein to whey protein has been shown to combine the benefits of both. You get the immediate shot of protein and aminos from the whey, and the slower digestion of casein prolongs the effects initiated by the whey, for up to 8 hours. 

A blend like this can be great for post-workout refueling, but also a between meal boost anytime, and for your bedtime protein shake. 

the last word

This one is pretty straightforward – mix some casein in your whey. If you’ve only been using whey, you’re racing to get your protein and missing out on the slow and steady side of things. If you’ve been using casein in a very specific way such as a bedtime shake, you can do much more with it. Mix it up, and get the benefits from both!