There are two major kinds of protein in milk, whether it be human, cow, goat, etc: Those two proteins are whey and casein. In cow’s milk, casein makes up the majority of the protein—about 80%. Whey makes up the remaining 20%. Whey protein is the soluble portion of milk protein. To visualize this, think of the liquid that sits on top of yogurt when you open a container of yogurt—that's whey protein.

Because it is the soluble portion of milk protein, whey is easily extracted out of milk. This occurs during the manufacturing of cheese. In fact, many years ago before anyone understood the benefits of whey, tons of whey protein was literally dumped down the drain by cheese manufacturers.

Today, whey is so popular, that there is a huge shortage of whey. That is causing the price of whey protein to rise at a quick rate. The extracted whey is run through a number of filtering processes to remove the majority of the fat and the carbohydrates, mainly lactose, from the milk, leaving the whey protein. The more filtering that the whey goes through, the purer the protein content and the lower the carbs and fat. After the filtering the whey is spray dried into a fine powder.

A lot of people are starting to have questions about what type of whey protein I use. It's obviously a whey protein isolate, but those who are a little more supplement savvy know that there are different ways that you can manufacture whey protein isolate.

There's a process that's called "ion exchange", which is a bit harsher in nature on the whey protein. This process basically uses chemicals to isolate the whey protein and make it pure. However, the problem is that you lose a lot of what we call "microfractions" from the whey—particularly the whey peptides, which we now know are absolutely critical to the benefits of whey.

Ion exchange typically removes all of the whey peptides. Ion exchange also causes the whey to lose all of its lactoferrin and glycomacropeptides. These microfractions have important properties that are provided by the whey. These can boost immune function, help you to prevent infection. They provide a host of benefits that go far beyond what we think a typical protein is going to deliver with just muscle growth—and yes, they're also critical for promoting muscle growth, particularly the peptides.

There's another way to process whey protein isolate, and this involves what we call "microfiltration", followed by "ultrafiltration"—and that's the processing that I use for the whey isolate that's in Pro JYM. Microfiltration followed by ultrafiltration basically just uses filters with no chemicals, which retains those important peptides—those microfractions—that I was discussing.

So if you're questioning what type of whey protein isolate is in Pro JYM, you can rest assured knowing that yes, it's whey protein isolate from microfiltration and ultrafiltration. That's a big difference.

There’s no debating the fact that whey protein is a superior protein when it comes to building muscle—and that's not just my opinion, it's based on numerous studies confirming whey's ability to trump other proteins for boosting muscle protein synthesis and increasing real, lean muscle mass over time.

That's because whey is the fastest-digesting protein that you can consume and it's one of the richest sources of the branched-chain amino acids (BCAAs) leucine, isoleucine, and valine. Not to mention, whey contains those specific peptides and subfractions that are so beneficial. These include: beta-lactoglobulin, alpha-lactalbumin, bovine serum albumin peptides, immunoglobulins, lactoferrin and lactoperoxidase, to name a few—all of which are critical for muscle growth, and provide antioxidant and immune-boosting properties.

Of course, I recommend adding at least casein protein to whey to extend the protein synthesis that whey initiates and further promote lean muscle mass gains, but whey is definitely the MVP of that team.

There are several reasons why whey is so effective at boosting muscle protein synthesis. The first is it's rapid rate of digestion. This means that its amino acids get rapidly absorbed into the bloodstream and travel to the muscles where they can quickly stimulate protein synthesis.

One of the first landmark studies showing how effective whey is for stimulating muscle protein synthesis was published in 1997 by French researchers. They reported that when subjects consumed a whey protein drink, protein synthesis increased by almost 70% as compared to a 30% increase when they drank a casein protein drink. They concluded that this was due to whey's rapid digestions rate. Their data showed that whey caused a large spike in blood levels of its amino acids in just 30 minutes with the peak levels being reached in little over 1 hour.

A second reason why whey boosts protein synthesis so well is due to its high concentration of branched-chain amino acids (BCAAs). Whey is one of the richest sources of the BCAAs—leucine, isoleucine and valine. Leucine is the real critical player here as research has shown that it acts much like a key in an ignition to literally turn on the process of protein synthesis.

A third reason why whey is so effective at boosting muscle protein synthesis is due to the fact that it boosts insulin levels. Insulin is an anabolic hormone that will help to drive the amino acids from whey into the muscles. Plus, insulin also turns on muscle protein synthesis.

And yet another reason why whey may be so effective at stimulating muscle protein synthesis is due to its ability to boost blood flow to muscles. This occurs through two different mechanisms. The most familiar to you has to do with nitric oxide (NO). New research shows that whey boosts NO levels.

But whey protein also contains peptides (short protein fragments) that are very similar to peptides that inhibit an enzyme known as angiotensin converting enzyme (ACE), which increases the constriction of blood vessels. These specific peptides in whey inhibit ACE and therefore allow greater blood vessel dilation, enabling greater blood flow to exercising muscles.

Thich enhances the delivery of nutrients such as the amino acids in whey, anabolic hormones like growth hormone and testosterone, and oxygen to muscle during exercise—all critical for energy and strength during the workout and for recovery and growth after the workout. The increased blood flow also enhances the muscle pump you get during the workout.

One study from Danish researchers found that subjects taking a whey protein shake before and after workouts for 14 weeks increased muscle growth by over 25%, while those consuming a carb drink saw no change in their muscle mass. The whey protein group also increased their squat jump height, while the carb group did not.

Another study from Australia reported that male bodybuilders supplementing with whey protein while following a 10-week weight-training program gained an average of 11 pounds of muscle, while those supplementing with casein protein alone gained barely 2 pounds. The bodybuilders taking the whey also increased their strength more on the bench press, squat and pulldown.

That’s right—whey protein can also aid fat loss. In fact, a brand new study from the USDA reported that men and women drinking two whey protein shakes per day for 12 weeks without dieting or exercise, lost 5 pounds of body fat, dropped an inch from their waist, and gained muscle—while those drinking a similar amount of soy did not see these positive changes in their body composition.

The researchers discovered that this was due to the fact that whey lowered levels of the hunger hormone ghrelin. This hormone signals the brain that you need to eat. So by lowering ghrelin, whey helps you eat less food. It also increases hormones that make you feel full. In fact, several studies have shown that whey subjects drink a whey shake about an hour before eating at a buffet-style meal, they feel fuller and eat far less at the meal. Other studies have also shown that whey protein helps to boost metabolic rate to help you burn more calories.

In addition to muscle growth, strength gains, and fat loss, whey also offers numerous health benefits. Whey has been found in clinical studies to increases levels of the powerful antioxidant, glutathione in the body, lower blood pressure, lower total and LDL, or bad cholesterol, and may even help to reduce the risk of certain cancers.

Some experts have argued that individual amino acids, such as the essential amino acids (EAAs) are even better than whey protein. This is due to the fact that whey protein is just made up of these amino acids, and since the individual amino acids don't have to be digested they can get absorbed more quickly and get to the muscles sooner. Makes sense from a speed standpoint—nd many athletes have taken up this advice.

However, a recent study shows that intact whey protein performs better than consuming the individual amino acids that make up whey protein.

Japanese researchers had rats swim for 2 hours to depress muscle protein synthesis and increase muscle breakdown. After the exercise one group of rats was supplemented with carbs and whey protein hydrolysate, which is partially digested whey. Another group consumed carbs and an amino acid mixture that contained the same amino acids in the same amounts as in the whey protein. And a third group consumed just the carbohydrate with no whey or aminos.

They reported in a 2013 issue of the British Journal of Nutrition that while both whey and the amino acid mix increased muscle protein synthesis far better than the carbs alone, whey protein boosted muscle protein synthesis significantly higher than the amino acid mixture despite the blood amino acid levels being identical between the two groups.

The scientists traced this back to whey's superiority in phosphorylating (basically activating) several important complexes that then initiate muscle protein synthesis. These include mTOR, which you may have heard before, as well as ribosomal protein S6 kinase and eukaryotic initiation factor 4E-binding protein 1 (eIF-4E BP1).

As explained above, milk protein is 20% whey protein and 80% casein protein. And you now know that whey is the fast-digesting protein of the two. Now, what about the micellar casein? That's the real slow component of Pro JYM.

Remember, what the research has now found is that using just whey alone is not the best way for muscle growth. Yes, whey is critical—those microfractions from whey are important; its fast digesting rate is important—but adding a very slow-digesting protein like micellar casein extends that metabolic effect from the protein powder and can help build more muscle growth; increase muscle protein synthesis, keep it elevated for longer. That's going to lead to greater muscle growth. It works very well.

But you need a real slow-digesting casein. When we talk about caseins in protein, I have micellar casein. You've probably seen caseinates—sodium caseinate, calcium caseinate—what's the difference between caseinates and micellar casein? It's a huge difference. I only use micellar casein.

Now "micellar casein" means that that casein is in its natural form. When you consume casein, it forms micelles in the stomach. If you basically think of the layers of an onion, these micelles digest very slowly because it's like stripping off layers of an onion—and that's how it digests very, very slowly.

Caseinates are sort of like the ion exchange method of producing whey protein isolates. Caseinates involve harsh chemicals—namely acid—to precipitate out the casein. These acids can disrupt that natural structure of those micelles. While this is good for mixability—caseinates mix a lot easier when you shake up your protein shake, and that's because those micelles—that globular portion of casein—is disrupted, so it mixes better. However, this makes the casein digest faster.

You've already got the whey in your protein blend for the fast digesting; now you want to focus on that very slow-digesting casein. Getting a casein that uses caseinates is not the way to go because it disrupts the natural structure of the micellar casein and it enhances the digestion, making it faster. That's the last thing you want—you want the slowest casein available with your whey protein.

Another problem with that acid is it disrupts some of the microfractions that are in casein as well, and these are important just like in the whey. These are also important. Whereas micellar casein only involves a filtration process much like the whey protein isolate that's microfiltered and ultrafiltered—this is all filtration-based proteins in Pro JYM.

The filtration process is a much gentler process because none of these harsh chemicals are used that can disrupt these tiny fragments which we're just beginning to really understand—how they work to enhance muscle growth and provide a host of other health benefits as well.

Many of you have wondered why I have milk protein isolate in Pro JYM. Milk protein isolate is just the milk protein in its natural form. What we know—and most of you probably know—milk protein is 20% whey and 80% casein. So why didn't I just use more of the microfiltered and ultrafiltered whey protein isolate and the filtered micellar casein to make up that remaining bit of whey and casein—why did I use milk protein?

Many of you may have heard me say that the JYM Supplement Science line—this is not a supplement business. This is an educational format, for me to teach you guys what good supplements look like. There are a lot of misconceptions about milk protein. People think it's an inferior protein; absolutely not. Long before we had whey protein powders, bodybuilders knew to drink milk.

They knew to consume dairy, and that provided milk protein—20% whey, 80% casein—which caused remarkable muscle growth along with the rest of their diet and their training programs. Milk protein is a very high-quality protein.

It's also a very gentle protein—it involves just a filtration process. I mainly put it in here as a teaching element, to show you that this is a very high quality protein. It's filtered, and when it's filtered that means it maintains the micellar casein structure and the true whey structure of milk protein. That means that all those microfractions are intact—it's truly the perfect protein source.

You've heard me say a lot that even a 50/50 blend of whey and casein is not the best way to go. We need a little bit of whey, but more casein than we originally thought to produce muscle growth. What I have found is the percentage breakdown in Pro JYM to be the best.

That's why I didn't go with a straight-up milk protein, but that would also be fairly decent—I just tweaked it a bit based on what I found in my lab—the gym—to work ideally at these exact amounts. This is a very high-quality protein source that gives you that micellar casein and the whey in the forms that they’re supposed to be in, with very little disruption—very, very gentle processing.

What the research has shown is that when you have that bit of very fast whey, mainly a larger amount of casein, and then a medium-digesting protein in the middle to bridge the gap, it promotes muscle protein synthesis and muscle growth better than just whey. What I have found is it's the fast whey and slow casein that are the most critical. Slightly less whey than casein—a bit more casein—most people are surprised.

And my views on this have changed over the years as I've worked with athletes and other individuals, and seen the research that has come out in the laboratories. We used to really focus on whey, and then we found that casein enhanced muscle growth. So, we started adding some casein, but still really focused on whey. Now we know it's actually the flip-side of that. You want a good deal of whey, but you really want to focus more on the casein aspect.